My next project

[NickH]

56560

Ive got the appropriate home for my GPA 416-8b woofers thanks too Esoteric Junkie.

Now comes the refurb. Does anyone have any advice on refurbing a pair of altec 828's?

I was planning on changing how the back panel attaches. Glued around the parameter with a opening a little bigger then the 416 in the back. And add more bracing on the back and side panels too. Im thinking I might add an extra layer of plywood on the outside to increase the rigidity too.

Nick

[sbjacob]

56560

Ive got the appropriate home for my GPA 416-8b woofers thanks too Esoteric Junkie.

Now comes the refurb. Does anyone have any advice on refurbing a pair of altec 828's?

I was planning on changing how the back panel attaches. Glued around the parameter with a opening a little bigger then the 416 in the back. And add more bracing on the back and side panels too. Im thinking I might add an extra layer of plywood on the outside to increase the rigidity too.

Nick
Very nice look forward to more photo's on the restore .:applaud:

[Lee in Montreal]

I would be curious to see how an A7 can be tuned thru proper Bass reflex. I wonder what would happen with a 2234 in there.

[NickH]

I saw that thread with the diy a7's with the reflex ports.

I though about trying something like that, and I still may. But the way I'm looking at it for the moment is altec knew what they were doing. I'll keep them stock, for now. I was already planning on running a subwoofer anyways.

I was going to start stripper the cabinets today, but my wife had other plans for me:dont-know::banghead:.

what's a guy going to do.

There at the shop I work at. So looks like I'll be working late this week:D.

I will post pictures of my progress as I go.

[Ear4life]

Hello NickH

Exiting project!
I love the 828! It for sure does good thing for the low mid and lows.
When it comes to the the bass port question, the standard opening in the front was only to get so much sensitivity out of the box as possible. They are from a time where extended lows wasn´t invented yet. The opening in the front lets a lot of midrange escape out there. I will not say it was a bassreflex hole, because it has "no tuning". I have "replaced" that open front on my 828 with three bassports. So I have lows now :). Have you thought about adding some wings on the sides of the cab?
Looking forward to read about your project, and subwoofer and stuff! :bouncy:

Best
Martin

[NickH]

Hello NickH

Exiting project!
I love the 828! It for sure does good thing for the low mid and lows.
When it comes to the the bass port question, the standard opening in the front was only to get so much sensitivity out of the box as possible. They are from a time where extended lows wasn´t invented yet. The opening in the front lets a lot of midrange escape out there. I will not say it was a bassreflex hole, because it has "no tuning". I have "replaced" that open front on my 828 with three bassports. So I have lows now :). Have you thought about adding some wings on the sides of the cab?
Looking forward to read about your project, and subwoofer and stuff! :bouncy:

Best
Martin

Hi Martin,

I have thought about the wing, just dont know how well they would fly with the wife. Did you get that, wings, fly, LOL. Corny. I am goping to try the though, one day. I figured that If I restricted the reflex port it would probably lower the sensativity.

But Im a long way away from this step. Ill try out a few things when I get there.

Nick

[sbjacob]

Hello NickH

Exiting project!
I love the 828! It for sure does good thing for the low mid and lows.
When it comes to the the bass port question, the standard opening in the front was only to get so much sensitivity out of the box as possible. They are from a time where extended lows wasn´t invented yet. The opening in the front lets a lot of midrange escape out there. I will not say it was a bassreflex hole, because it has "no tuning". I have "replaced" that open front on my 828 with three bassports. So I have lows now :). Have you thought about adding some wings on the sides of the cab?
Looking forward to read about your project, and subwoofer and stuff! :bouncy:

Best
Martin
Martin what size ports did you use and can you post some photo's also did you run any tests and if so would you mind posting the results? Thanks

[Ear4life]

Nick:
Just tell your wife that she is an angle, and the idea of the wings came from looking at her :D. In my head, she will buy it... I haven´t installed any wings. I do not have the space my living room so it has to wait...
I don´t know if you can say you lower the sensitivity by adding ports instead. Well yes below 100 you will flatten it more out but you might have a peak somewhere according to that big opening (also depending on the driver)... By the way, what subwoofer(s) are you going to add?

sbjacob:
I will post some pics in my thread later on today ( if I can find some on the laptop, I´m on vacation) :)

Best
Martin

[Alien_Shore]

Looking forward to seeing this project progression, Nick.
Martin's DIY 828 is a cool project - you should have a look at that; essentially blocking up that giant port and put some ducts in there. What is the Fs of the GPA 416-8B? Is it around 23 Hz? Perhaps you can design a removable port board?

[Lee in Montreal]

I always thought that the A7 design paired to a woofer with a low Fs and proper BR ducting can sound pretty sweet. That design can also be modified by enlarging/reducing the lower volume to accomodate any woofer's TS.

[NickH]

Agh, will the sanding ever end. That Altec gray is some tough paint. The paint stripper I got wont even touch the stuff.


On a odd side note, the paint stripper I got looks exactly like the slime from the second ghost busters movie. Pinkish with chunks in it. Ill take a picture of the stuff.

Ive always been a ghost busters junky. Some of the funniest movies ever made. Well Not including any Mel brooks flicks, :D.


But progress is happening but slow. When I get a little farther along Ill post. I will get more done this weekend.

Nick

[loach71]

Agh, will the sanding ever end. That Altec gray is some tough paint. The paint stripper I got wont even touch the stuff.


On a odd side note, the paint stripper I got looks exactly like the slime from the second ghost busters movie. Pinkish with chunks in it. Ill take a picture of the stuff.

Ive always been a ghost busters junky. Some of the funniest movies ever made. Well Not including any Mel brooks flicks, :D.


But progress is happening but slow. When I get a little farther along Ill post. I will get more done this weekend.

Nick

This may sound like heresy, but my proven method for the removal of recalcitrant finishes is soda blasting. It is like sand blasting, but uses Sodium Bicarbonate (baking soda) as the blasting medium. An experienced operator can remove the surface finish with no damage to the underlying substrate. I used this technique on my old Corvettes, and it didn't even harm the gel coat underneath the paint. I then went on to use it on some weirldy painted JBL 2360A fiberglass horns and some EV SM120 horns all with great success.

[Lee in Montreal]

Gel coat is pretty hard compared to wood. I think that using chemical stripper remains the best way. It sure takes a long time but it works without destroying the base surface. I have myself stripped several cars before restoration. I prefer using chemical stripping to remove most of the paint and undercoats. It sure is time consuming but it will not damage the sheetmetal. I would then sand all the flat or curvy surfaces, and use beadblasting only on areas that are not easily accessible.

[NickH]

Well I ditched the idea of paint stripper. Too many loose strips of wood that get caught on the putty knife. Im now using a belt sander to clean up the surfaces. Helps smooth it out too. Ill do finish sanding before I go in with the filler and straighten everything out and get it square, I found the the joints do need to be reinforced. So Ill use 2x4 and plane the to size to go over the original glue blocks altec put in. Basically Ill surround the altec block.

This is probably over kill since Im going to glue 1/2" plywood to the outside panels. But, it couldnt hurt.

Ear4life, sorry I missed the part where you asked me about a subwoofer. Im toying with quite a few ideas. From a selaed cabinet with 2 15" woofers. Or building a jbl 4688 with 2 2240's in it. I like the 4688 because of the higher sensitivity. But I have made up my mind yet. Got to concentrate on one thing at a time or I wont finish it, LOL.

[NickH]

Today was the first real day I've had to work on the cabinets. One is completely stripped sanded and reactive filler. The second is stripped except for the horn. I had to replace some of the bottom glue block with 2x 2's. I have to do the same with the other cabinet tomorrow.

I was going to take picture but my cell died. I'll take some first thing tomorrow and post them. But progress is happening.

[NickH]

5667956680Busy weekend but I did get the paint stripped off the outside of the cabinets. Still a few spots to clean up still on the edges. I'm going to start adding extra bracing next. I'll add some photos in the morning since I can't do it from my tablet.

[NickH]

Ive added some bracing to the cabinet. This is what I have done so far. More is needed thought on the top of the cabinet. It resonate when I put a sander to it. Havent figured out how Im going to do it though. Sorry for the fuzzy pictures.
Nick



56701

[Ear4life]

Hey Nick!

Looking good so far! Is it possible to take off the sidepanels and glue them on agen? and did you heare them sing before you took them apart? I must say that I´m clapping my small hands.. those vott speakers will never die!! :bouncy: (hopefully)... By the way, what HF driver/horn du you have? Sorry for all the questions :D

Martin

[NickH]

Hi Martin,

I did not take the sides off. Im sure someone could do it, but I wouldnt try. I realize the bracing is a tad overboard. What you cant tell in the other pictures is the cabinets had become a bit flimsy do to the beating that had endured over the years. Not they are nice and sturdy:D.


As for horns I have a pair of altec MRII 542 mantarays Im going to use at first. Im using jbl 2440's as the mid drivers so Im using an adapter to put them together. I want some jbl 2397's or 2360a's in the future.

Nick


Hey Nick!

Looking good so far! Is it possible to take off the sidepanels and glue them on agen? and did you heare them sing before you took them apart? I must say that I´m clapping my small hands.. those vott speakers will never die!! :bouncy: (hopefully)... By the way, what HF driver/horn du you have? Sorry for all the questions :D

Martin

[NickH]

Just got off the phone with a guy at GPA. If I brace the hell out of these and fill the horn bells with foam. I should run 2 4" diameter vent tubes at 6.5" long. Thats tuned to 28.7 hertz. -3db is 31 hertz.. Very nice.



Much better then tuning for 100 hertz which was the stock configuaration.


Nick

[NickH]

What is the best way to attach dampening material? Staples or adhesive? Im planning on using plan old fiberglass..

This is the stuff I was thinking about using.

http://www.lowes.com/pd_35136-1722-B777CT40_4294858103__?productId=3364428&Ns=p_product_price|0


Or would that not be a good choice?



Thanks,
Nick

[Ear4life]

Martin what size ports did you use and can you post some photo's also did you run any tests and if so would you mind posting the results? Thanks

sbjacob: Sorry for the late answer, my ports are Ø10 cm. Are there any specific things you want me to take pictures of?

Best regards
Martin

[NickH]

I put foam in the horn bells. I thought it would dampen them but it did not. I only put it in one but I'm going to remove it. I'm going try some rv roof paint on some thin plywood and see if it dampens it.

if not I'm going to try some asphalt roof cement.

Nick

[hjames]

I put foam in the horn bells. I thought it would dampen them but it did not. I only put it in one but I'm going to remove it. I'm going try some rv roof paint on some thin plywood and see if it dampens it.

if not I'm going to try some asphalt roof cement.

Nick

I'd try something else like Rope Caulk or silicon bathtub caulk that can be peeled off if you don't like what it does.

I think one of the folks here sprayed the outside of a ringing horn with that truck bed liner stuff -
which I gather is a combo rubber/foam/undercoat type product - but that kind of stuff is much more permanent and hard to remove

[NickH]

Hi Heather,

I'm not putting it on the inside of the horn. Its the outside the horn bells inside the cabinet. But I'm going to do some experimenting first before I use it on the horns. Silicone is a really good idea. But I don't think it would work to well here. Its a tight squeeze getting in there. I don't even I can't get a brush in there.

The reason I'm thinking about the asphalt cement is asphalt seem to do very good at deadening vibrations. That's what things like dynamat is made of. I would use dynamat but its just so expensive.

My experimental method isn't very complex. Just coat some 1/4" plywood with it and tap on it with a hammer to see if it sounds dead.

But that being said I think I might try out some rtv silicone just to see how it performs. Just might be quite tricky applying it to the inside of the horn cavities.

Nick




I'd try something else like Rope Caulk or silicon bathtub caulk that can be peeled off if you don't like what it does.

I think one of the folks here sprayed the outside of a ringing horn with that truck bed liner stuff -
which I gather is a combo rubber/foam/undercoat type product - but that kind of stuff is much more permanent and hard to remove

[hjames]

Well, I didn't think you were putting stuff inside the bell (grin) ... but I have heard folks use all kinds of material like auto-rustproofing kind of tar and such - or even canned self-expanding foam from Home Despot.

I think the guys with the spray-on bed liner stuff used cheap paint guns and then cleaned them thoroughly -
I've read a number of these kinds of projects over the 7+ years I've been reading here ...



Hi Heather,

I'm not putting it on the inside of the horn. Its the outside the horn bells inside the cabinet. But I'm going to do some experimenting first before I use it on the horns. Silicone is a really good idea. But I don't think it would work to well here. Its a tight squeeze getting in there. I don't even I can't get a brush in there.

The reason I'm thinking about the asphalt cement is asphalt seem to do very good at deadening vibrations. That's what things like dynamat is made of. I would use dynamat but its just so expensive.

My experimental method isn't very complex. Just coat some 1/4" plywood with it and tap on it with a hammer to see if it sounds dead.

But that being said I think I might try out some rtv silicone just to see how it performs. Just might be quite tricky applying it to the inside of the horn cavities.

Nick

[NickH]

Kind of a tricky one to explain. But ya not in the business end of the horn. The optimal volume for the cabinet is with the horn bells filled. I did use foam to do it. But it didn't work that well.

Nick




Well, I didn't think you were putting stuff inside the bell (grin) ... but I have heard folks use all kinds of material like auto-rustproofing kind of tar and such - or even canned self-expanding foam from Home Despot.

I think the guys with the spray-on bed liner stuff used cheap paint guns and then cleaned them thoroughly -
I've read a number of these kinds of projects over the 7+ years I've been reading here ...

[Lee in Montreal]

To dampen the horn, you could use some square panels of thick tar from the automotive industry.

[NickH]

Im not too familiar with that stuff. Cant you give me a link to a manufacturer of the stuff? How thick is it? Im guessing its installed with heat.

Tar seems to work really well and its cheap, LOL.



To dampen the horn, you could use some square panels of thick tar from the automotive industry.

[Lee in Montreal]

Tar panels, ranging from 2mm and up are used in the automotive industry to keep flat sheet panels from vibrating by adding inertia/mass. Otherwise the car would literally be a bell. You can also find variations in the automotive sound system world where people apply massive amount of such panels to keep the car from resonating. Most often, those panels have a peel-off/stick-on back. Therefore they are very easy to use.

http://ecx.images-amazon.com/images/I/61is9RnhK5L._SS500_.jpg

Dynamat is the original supplier. But they are very expensive. You can find similar products for much cheaper.

http://www.b-quiet.com/extreme.html

http://www.b-quiet.com/images/extremefullres.jpg

For one tenth the price, you can go to your local Lowes renovation center and get roofing material. ;-)

http://www.scroungers.net/t475-cheap-alternative-to-dynamat

http://i123.photobucket.com/albums/o302/rebstew187/Picture-1.jpg

You can find thicker stuff from other sources. The thicker, the better. I also suspect that every single panel in your A7 would benefit from a sheet or two of such sound deadening material to keep them from vibrating. Old wood, thin wood, dry wood will easily resonate.

[NickH]

Ok thats what I thought it was. We are on the same page. Thats why I was going to try the asphalt roof cement.

Heres a link.

http://www.homedepot.com/h_d1/N-5yc1v/R-100278428/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=karnak&storeId=10051

Just think this would be easier to put on in the tight space.


Has a thick consistency. So I would put it on with a putty knife. Works on vertical surfaces. Only 14 bucks for a can so I figured I might as well give it a try.



Tar panels, ranging from 2mm and up are used in the automotive industry to keep flat sheet panels from vibrating by adding inertia/mass. Otherwise the car would literally be a bell. You can also find variations in the automotive sound system world where people apply massive amount of such panels to keep the car from resonating. Most often, those panels have a peel-off/stick-on back. Therefore they are very easy to use.

http://ecx.images-amazon.com/images/I/61is9RnhK5L._SS500_.jpg

Dynamat is the original supplier. But they are very expensive. You can find similar products for much cheaper.

http://www.b-quiet.com/extreme.html

http://www.b-quiet.com/images/extremefullres.jpg

For one tenth the price, you can go to your local Lowes renovation center and get roofing material. ;-)

http://www.scroungers.net/t475-cheap-alternative-to-dynamat

http://i123.photobucket.com/albums/o302/rebstew187/Picture-1.jpg

You can find thicker stuff from other sources. The thicker, the better. I also suspect that every single panel in your A7 would benefit from a sheet or two of such sound deadening material to keep them from vibrating. Old wood, thin wood, dry wood will easily resonate.

[NickH]

Nothing much to report on the progress. Im filling in defects at the moment. Im working on one cabinet at a time now. Otherwise it seems like im not getting anything done.

I did decided Im going to put 3/4" baltic birch ply on the sides and bottom of the cabinets. It going to make them heavy but I have most of the ply on hand so I only have to buy a little bit.

Ill post some pictures soon.


Nick

[NickH]

Well I glued some 3/4" birch ply on the sides of one cabinet this weekend. Went well. There getting heavy, LOL. I also got some asphalt roof flashing cement to try for dampening the horn flares. I put the stuff on a piece of 1/4" plywood. Im surprised that the stuff doent really have much of an odor. It takes a long time to cure but so far it works prtty well. Looks like goose poop though, :eek:. But I can knock on the wood pretty hard and all I get is a thud. So it looks like it

Today I started filling in the gaps on the front of the cabinet. The original plywoods corners are rounded over from years of road use. So theres a little gap on the periphery.

567705677156772

Here are some photos of the progress. The dampening material I tried. And the experiment.

Not in any particular order.

Nick

[intercity125]

Hi Heather,

I'm not putting it on the inside of the horn. Its the outside the horn bells inside the cabinet. But I'm going to do some experimenting first before I use it on the horns. Silicone is a really good idea. But I don't think it would work to well here. Its a tight squeeze getting in there. I don't even I can't get a brush in there.

The reason I'm thinking about the asphalt cement is asphalt seem to do very good at deadening vibrations. That's what things like dynamat is made of. I would use dynamat but its just so expensive.

My experimental method isn't very complex. Just coat some 1/4" plywood with it and tap on it with a hammer to see if it sounds dead.

But that being said I think I might try out some rtv silicone just to see how it performs. Just might be quite tricky applying it to the inside of the horn cavities.

Nick


Hi Nick,

Awesome project! I look forward to seeing the final results. In fact, I will be starting yet another one myself... a pair of bass enclosures for the 416 driver. I am going to model them after the Altec 620's, but with some added refinements. Anyway, since there was some talk about damping, I thought I would chime in. I use a product from Dupli-Color called "Professional Undercoat and Sound Eliminator." It is amazing stuff, and unlike all the other rubberized sprays on the market, this one does not leave a shiny, smooth surface. Rather it has more of a bituminous texture that really deadens sound. I use it inside of all my speaker cabinets/projects. Most recently, a pair of Klipsch Belles that I refurbished. The only place I have found to carry it around here is Pep Boys. They keep it next to all the paints and auto body products. Just something to consider down the road.

Willy

[NickH]

Hi Willy,

I bet you a dollar that can is filled with basically the same thing as this cement. Asphalt. And low and behold, it is. Heres a link to the msds.
http://www.paintdocs.com/webmsds/webPDF.jsp?SITEID=DUPLI&prodno=026916601025&doctype=MSDS&lang=2

The reason Im drawn to the cement is the price. Most products that are for dampening carry a high price tage. This stuff can be had for 15 bucks a gallon.

This is what Im trying.
http://www.karnakcorp.com/19Flashing.aspx





Hi Nick,

Awesome project! I look forward to seeing the final results. In fact, I will be starting yet another one myself... a pair of bass enclosures for the 416 driver. I am going to model them after the Altec 620's, but with some added refinements. Anyway, since there was some talk about damping, I thought I would chime in. I use a product from Dupli-Color called "Professional Undercoat and Sound Eliminator." It is amazing stuff, and unlike all the other rubberized sprays on the market, this one does not leave a shiny, smooth surface. Rather it has more of a bituminous texture that really deadens sound. I use it inside of all my speaker cabinets/projects. Most recently, a pair of Klipsch Belles that I refurbished. The only place I have found to carry it around here is Pep Boys. They keep it next to all the paints and auto body products. Just something to consider down the road.

Willy

[intercity125]

Hi Willy,

This is what Im trying.
http://www.karnakcorp.com/19Flashing.aspx

The Karnak looks like great stuff, too. Also, I like that you can get it in an industrial size can. It will definitely go a lot further than the Dupli-Color spray cans I am using now. Thanks for turning me on to it. BTW, are you brushing it on, or can it be applied with a spray applicator?

[NickH]

The first test I used the caulk tube. But that was just because I didnt want to buy a gallon can and didnt know if it was going to work or not. The caulk gun tube is handy but it cost more. I was going to try and put it on with a putty knife at first. But I need to do more experimenting to find the best way.

Nick


The Karnak looks like great stuff, too. Also, I like that you can get it in an industrial size can. It will definitely go a lot further than the Dupli-Color spray cans I am using now. Thanks for turning me on to it. BTW, are you brushing it on, or can it be applied with a spray applicator?

[intercity125]

The first test I used the caulk tube. But that was just because I didnt want to buy a gallon can and didnt know if it was going to work or not. The caulk gun tube is handy but it cost more. I was going to try and put it on with a putty knife at first. But I need to do more experimenting to find the best way.

Nick

I suppose one just has to trowel (or putty knife) it on as smoothly and evenly as possible. Alternatively, I see a few places on-line where you can get fillable caulk tubes. That may make it easier to apply, then all you have to so it smooth it to effect.

[NickH]

I might have to check those out. The one thing I do know about this stuf is it take awhile to cure. Over 24 hours. I havent tested it's ability to flow when effected by gravity yet. Just put it on a horizontal surface, at the moment.


I suppose one just has to trowel (or putty knife) it on as smoothly and evenly as possible. Alternatively, I see a few places on-line where you can get fillable caulk tubes. That may make it easier to apply, then all you have to so it smooth it to effect.

[intercity125]

Hey Nick,

Do you have the crossovers for this project yet? Just curious. If so, what do you have? If not, do you know what you are going to use?

Willy

[NickH]

Hi Willy,

I was planning on going active. Using a minidsp. If you need inspiration there are plenty of altec and jbl crossovers that you could clone.




Hey Nick,

Do you have the crossovers for this project yet? Just curious. If so, what do you have? If not, do you know what you are going to use?

Willy

[intercity125]

I see. Well, it seems to be the way things are going, these days. I've yet to venture down that road; however, I can see where going active makes perfect sense. A good friend of mine from Universal City has a wonderful pair of Emerald Physic 2.3's that use an active crossover, and the slopes and crosses are literally endless. Want to change the tone, push a button. Want to shift the soundstage, push a button. It's like auditioning a new pair of loudspeakers with every change. Great stuff, really. I may have to go that route after I refurb my KEF 105's.

[NickH]

The in the realm of rf engineers they alway say" why do it high level when you can do it in low level". Seems to make since here too. Just mean you need multiple amps. But in a world where you can get class d amp borads that sound quite good for around 100 bucks and produce anywhere from 8 watts per channel up to 300 watts per channel. Works for me. Just need to supply the power supply.
Nick


I see. Well, it seems to be the way things are going, these days. I've yet to venture down that road; however, I can see where going active makes perfect sense. A good friend of mine from Universal City has a wonderful pair of Emerald Physic 2.3's that use an active crossover, and the slopes and crosses are literally endless. Want to change the tone, push a button. Want to shift the soundstage, push a button. It's like auditioning a new pair of loudspeakers with every change. Great stuff, really. I may have to go that route after I refurb my KEF 105's.

[NickH]

56774

Almost done with the first box. I wonder how these would sound with a sealed box. Oddy enough they sim quite well in win isd.

[sbjacob]

56774

Almost done with the first box. I wonder how these would sound with a sealed box. Oddy enough they sim quite well in win isd.
Those are looking very cool I bet they will put out some nice LF with all the added cabinet support.

[Ear4life]

Hey Nick!

Nice progress! You should put some wheels on them before you start the painting job, so you don´t have to move them the way you are doing it now ;)
Have you glued the front panel on or is it still removable?

Best
Martin

[NickH]

Thanks Ara,

Ears,

there wonlt be much of any paint on them. Im going to put wood veneer on them. The only part that will be painted is the front of the baffle board on the back of the horn. It wouldnt be very wasy to put veneer on it with the glue block at the top.

Still alot more work to do. I also decided I am going to put a piece of 3/4" ply on the tops of them. The top still resonates when the sander touches it. They are getting nice and heavy though. Good thing they arent going to move much once they are in place.


Nick

[sbjacob]

Thanks Ara,

Ears,

there wonlt be much of any paint on them. Im going to put wood veneer on them. The only part that will be painted is the front of the baffle board on the back of the horn. It wouldnt be very wasy to put veneer on it with the glue block at the top.

Still alot more work to do. I also decided I am going to put a piece of 3/4" ply on the tops of them. The top still resonates when the sander touches it. They are getting nice and heavy though. Good thing they arent going to move much once they are in place.


Nick
Nick have you considered staining them and hitting them with a few coats of water base poly they would look very nice and would save time as veneering can be very time consuming well let me rephrase that "Time consuming for me" :blink:it may not be for you ether way they will look awesome and sound great I love my Altec's wish I had more room

[NickH]

All except for the bondo I used for filler. I've always wanted to try to veneer something and I figuared this would be a good way to try it.




Nick have you considered staining them and hitting them with a few coats of water base poly they would look very nice and would save time as veneering can be very time consuming well let me rephrase that "Time consuming for me" :blink:it may not be for you ether way they will look awesome and sound great I love my Altec's wish I had more room

[intercity125]

All except for the bondo I used for filler. I've always wanted to try to veneer something and I figuared this would be a good way to try it.

Hi Nick,

It's a perfect opportunity... just 'go for it.' I believe you have a Rockler woodworkers retail store down your way, they have a great selection of veneers to choose from. I have been using pressure sensitive veneers (PSA) of late, and really love the ease in which they can be applied. I finished my Klipsch Belles in walnut PSA and they came out beautiful.

Willy

[NickH]

Oh I didn't know that. There goes the rest of my project money,lol. There is actually a few good places to buy veneer and hardwood here in Houston.

I'm actually thinking about doing it the old fashion way, hammer veneer. Except for the horn though. PSA would be the best there. There is so many opinions though. Its quite daunting. I'd like to try something fancy into don't want to get carried away.

I did cut the vent in one cabinet today. I went with a rectangular vent. It was 2 inches tall and 10 inches wide. 1.5 inches deep. I just used another layer of 3/4" plywood on the back of the baffle to get the depth.

I might actually be able to test one of these out soon. But there's still plenty of work to do. I still have to put a piece of ply on the top of both cabs. And then there's more filling and sanding to do. But I'm taking my time so I don't get impatient and screw something up.

Nick


Hi Nick,

It's a perfect opportunity... just 'go for it.' I believe you have a Rockler woodworkers retail store down your way, they have a great selection of veneers to choose from. I have been using pressure sensitive veneers (PSA) of late, and really love the ease in which they can be applied. I finished my Klipsch Belles in walnut PSA and they came out beautiful.

Willy

[NickH]

56802

Here they are as of now. You can see how I cut the vent. Much smaller then stock. Should go down close to 30Hz now. Im hoping I dont have any port noise. Ill test it out soon.

[sbjacob]

56802

Here they are as of now. You can see how I cut the vent. Much smaller then stock. Should go down close to 30Hz now. Im hoping I dont have any port noise. Ill test it out soon.
Nick I like what you did with the bottom side tie-in gives them a nice stance.:applaud:

[NickH]

Ya I though so too. At first I was going to put a piece of wood in the front to fill the space between the feet. But I'm having second thoughts.

Should be firing one up soon to test it out. But I've been sick since mid last week so I have limited energy. Really sucks too since the weather was very nice over the weekend.




Nick I like what you did with the bottom side tie-in gives them a nice stance.:applaud:

[intercity125]

56802

Here they are as of now. You can see how I cut the vent. Much smaller then stock. Should go down close to 30Hz now. Im hoping I dont have any port noise. Ill test it out soon.

Hey Nick,

I love what I am seeing so far; keep it coming! Did you use one of those on-line port calculator programs to come up with the slot size, or did you just use an educated guess? Just curious, as I will be building my custom Altec LF cabinets soon, and since they are going to be a cross between a 620 and 612, I will needto calculate a port size for them. Cheers!

Willy

[NickH]

Hey Willy you can download WINisd. Its freeware and its the sim I use. I use the beta since I have been having issues with the alpha. But it works great you just need the ts parameters for your driver.


Hope this helps.


P.S. Im testing one out right now, sounds great.

Nick



Hey Nick,

I love what I am seeing so far; keep it coming! Did you use one of those on-lineport calculator programs to come up with the slot size, or did you just use aneducated guess? Just curious, as I will be building my custom Altec LF cabinetssoon, and since they are going to be a cross between a 620 and 612, I will needto calculate a port size for them. Cheers!

Willy

[intercity125]

Very helpful... thanks! I'll load it up after work. BTW, glad to hear that your test sample is sounding so good. Can't wait to begin my project.

[NickH]

Im having a blast. I never in a million year would have thought I would have a pair of altec a7's. Now I need to cut the vent in the other cabinet and put the strip on the the back panel mounts too.
WINIsd works quit well. I found it about a year ago and have been using it ever since. And Im cheap so it being free is a major plus. Dont know how accurate it is but a lot of people use it.


Nick


Very helpful... thanks! I'll load it up after work. BTW, glad to hear that your test sample is sounding so good. Can't wait to begin my project.

[sbjacob]

Im having a blast. I never in a million year would have thought I would have a pair of altec a7's. Now I need to cut the vent in the other cabinet and put the strip on the the back panel mounts too.
WINIsd works quit well. I found it about a year ago and have been using it ever since. And Im cheap so it being free is a major plus. Dont know how accurate it is but a lot of people use it.


Nick
Nick you have a nice big area to fire those up they will sound very good in that big room .:)

[NickH]

The room they will reside in is 33 feet long and 22 feet wide, so not small. They were in the shop I work at still. Just need to buy plywood for the tops of both cabinets and finally do all the filling. Plus there dampening the cabinets and the horns.

On the topic of dampening the horn I have my verdict on the Karnak flashing cement. Its been drying on the board since the day before labor day. I put the board in the vertical position last weekend to see if gravity would cause it to flow. It did not. This is worse case sinerio too as its quite hot in the garage in the summer time. It has hardened a bit but its still a little soft. Its about the hardness of clay. So in the cabinet when there in the nice cool a.c. I sure it will be harder.

My other concern was the smell. Well, I don't even smell asphalt. Its more like a solvent smell like paint thinner. It not strong either. I only smell it when I stick my nose up to it too.


Nick you have a nice big area to fire those up they will sound very good in that big room .:)

[intercity125]

Hi Nick,

Sounds like the Karnak is going to work out great. Did you ever check into those fillable caulk tubes? Just curious.

As for horn damping, what I used for my Belle's horns, and will also be using for my 511B's, is a rubberized spray-on truck bed liner. It's kind of like Rhino-Lining but not as thick. I don't have any scientific data to back this up, but the difference in sound from the pre sprayed Belle horn to the sprayed horn was noticeably different; to my ears, anyway. If I had to give a description of the change, I'd say the sound became smoother. I don't think the Belle's horns ever had a "ringing" problem like some people describe of the 511B's, but they sure sounded good after the spray was applied. I used about 4 coats on the outside and a single coat on the inside, which did not detract from their shape in any way. In fact, they looked rather good, although in a Belle, you'll never see them anyway unless you looked around back.

Anyway, just something to consider for your horns.

Willy

[NickH]

Hey Willy,

Once I get a little farther along I'll put more thought into how to get the stuff in there. I worked on the cabs for about 4 hours today. I put a piece of 3/4" on the tops of the cabs. I glued in the back panel flange on the last cab and worked on the reflex vent. Doesn't sound like much when I type it out does it. I'll be be putting the dampening in soon though. I'll be putting 100% of my time to filling and leveling the sides out next. That's going to take a bit of time. I have done some filling on one cab but not the other one.

but progress is being made.

I actually thought about using the bedliner but I went for the cheaper option:D.





Hi Nick,

Sounds like the Karnak is going to work out great. Did you ever check into those fillable caulk tubes? Just curious.

As for horn damping, what I used for my Belle's horns, and will also be using for my 511B's, is a rubberized spray-on truck bed liner. It's kind of like Rhino-Lining but not as thick. I don't have any scientific data to back this up, but the difference in sound from the pre sprayed Belle horn to the sprayed horn was noticeably different; to my ears, anyway. If I had to give a description of the change, I'd say the sound became smoother. I don't think the Belle's horns ever had a "ringing" problem like some people describe of the 511B's, but they sure sounded good after the spray was applied. I used about 4 coats on the outside and a single coat on the inside, which did not detract from their shape in any way. In fact, they looked rather good, although in a Belle, you'll never see them anyway unless you looked around back.

Anyway, just something to consider for your horns.

Willy

[intercity125]

Hey Willy,

Once I get a little farther along I'll put more thought into how to get the stuff in there. I worked on the cabs for about 4 hours today. I put a piece of 3/4" on the tops of the cabs. I glued in the back panel flange on the last cab and worked on the reflex vent. Doesn't sound like much when I type it out does it. I'll be be putting the dampening in soon though. I'll be putting 100% of my time to filling and leveling the sides out next. That's going to take a bit of time. I have done some filling on one cab but not the other one.

but progress is being made.

I actually thought about using the bedliner but I went for the cheaper option:D.


Hi Nick,

There's really no right or wrong. Some things just work better than others. The trick is finding the good ones!

I feel exactly as you when you say, 'doesn't look like much when I type it out.' These projects are a labor of love, but can be so time consuming. Sunday is the only day I can really devote to 'projects' so I have to make every minute count. You mentioned filling and leveling... I can spend an entire day (or two) doing just that. It's a laborious process, and doesn't seem to do much in the way of furthering a project; however, I know it's a crucial step and must be done.

I've been building a pair of Audio Nirvana Super 8 Monitors for the last two months, and even at their size it seems to have taken forever. I only have a little sanding to complete and then install the veneer and they're done. Then I can begin the big project on the Altec LF cabinets for my 511B's. I'll be sure to add pics, just as you have with yours.

Willy

[NickH]

Hey Willy,What really doesn't help is I'm getting over a nasty cold too. Even with a dust mast I'm dieing after an hour of cutting or sanding. I will be so glad when its out of my system. That was the reason I stopped yesterday as I was coughing my brains out.
Hi Nick,There's really no right or wrong. Some things just work better than others. The trick is finding the good ones!I feel exactly as you when you say, 'doesn't look like much when I type it out.' These projects are a labor of love, but can be so time consuming. Sunday is the only day I can really devote to 'projects' so I have to make every minute count. You mentioned filling and leveling... I can spend an entire day (or two) doing just that. It's a laborious process, and doesn't seem to do much in the way of furthering a project; however, I know it's a crucial step and must be done.I've been building a pair of Audio Nirvana Super 8 Monitors for the last two months, and even at their size it seems to have taken forever. I only have a little sanding to complete and then install the veneer and they're done. Then I can begin the big project on the Altec LF cabinets for my 511B's. I'll be sure to add pics, just as you have with yours.Willy

[intercity125]

Hey Willy,What really doesn't help is I'm getting over a nasty cold too. Even with a dust mast I'm dieing after an hour of cutting or sanding. I will be so glad when its out of my system. That was the reason I stopped yesterday as I was coughing my brains out.

Yeah, that's a bummer. I hope you feel better soon, so you can get back to it hard and heavy... we need more pics! ;)

[sbjacob]

Yeah, that's a bummer. I hope you feel better soon, so you can get back to it hard and heavy... we need more pics! ;)
Hi Nick hope your recovered any update on the restore?

[NickH]

Hi Nick hope your recovered any update on the restore?

Well if it's not one thing its another. I was looking forward to getting a bunch of work done last weekend. But Saturday I pulled my back out. Sucks. Im hoping maybe this wekend, but I doubt it.

[intercity125]

Hey Nick,

It's been a while since we've heard from you; hope all is well and that you're doing okay. How's the Altec project coming along? We'd sure love to know where you're at with it. Give us an update when you get the chance. Cheers!

Willy

[NickH]

Ya I am. My wife and I just got into out new house. Before that I was making sure everything got done right so we could move into our new house. The altecs got moved from my work to my new garage. At the moment the garage is a little tight with the boxes and all. But Im hoping to get back to them real soon. Cant been soon enough. I cant wait to fire these bad boys up and listen to some tunes.

I decided to forgo the veneer and paint them gray. Just feels better that way.

As soon as I get back to it ill post some more pictures. Not a whole lot left. Just some more filling sanding and then paint. Oh and putting some tar in the old horns too, LOL.


That sounds kind of obscene:blink:

Nick

[intercity125]

Ya I am. My wife and I just got into out new house. Before that I was making sure everything got done right so we could move into our new house. The altecs got moved from my work to my new garage. At the moment the garage is a little tight with the boxes and all. But Im hoping to get back to them real soon. Cant been soon enough. I cant wait to fire these bad boys up and listen to some tunes.

I decided to forgo the veneer and paint them gray. Just feels better that way.

As soon as I get back to it ill post some more pictures. Not a whole lot left. Just some more filling sanding and then paint. Oh and putting some tar in the old horns too, LOL.


That sounds kind of obscene:blink:

Nick

Hi Nick,

Glad to hear that all is well. And, congratulations on the new house. It's a lot of work moving into a new house, or any house for that matter. No wonder you've been off the radar.

I think going gray is a great idea, and is so much easiet than trying to veneer a speaker of that size. I'm planning on doing a version of the Altec 612, with the 511's on top, and I'm going to do them in a semi-metalic gray.

Anyway, enjoy the new house, and when you get settled in and back to work, snap us a few pics of the finished product. Cheers!

Willy

[NickH]

Hi Nick,

Glad to hear that all is well. And, congratulations on the new house. It's a lot of work moving into a new house, or any house for that matter. No wonder you've been off the radar.

I think going gray is a great idea, and is so much easiet than trying to veneer a speaker of that size. I'm planning on doing a version of the Altec 612, with the 511's on top, and I'm going to do them in a semi-metalic gray.

Anyway, enjoy the new house, and when you get settled in and back to work, snap us a few pics of the finished product. Cheers!

Willy

Will do.

[loach71]

Hi Nick,

Sounds like the Karnak is going to work out great. Did you ever check into those fillable caulk tubes? Just curious.

As for horn damping, what I used for my Belle's horns, and will also be using for my 511B's, is a rubberized spray-on truck bed liner. It's kind of like Rhino-Lining but not as thick. I don't have any scientific data to back this up, but the difference in sound from the pre sprayed Belle horn to the sprayed horn was noticeably different; to my ears, anyway. If I had to give a description of the change, I'd say the sound became smoother. I don't think the Belle's horns ever had a "ringing" problem like some people describe of the 511B's, but they sure sounded good after the spray was applied. I used about 4 coats on the outside and a single coat on the inside, which did not detract from their shape in any way. In fact, they looked rather good, although in a Belle, you'll never see them anyway unless you looked around back.

Anyway, just something to consider for your horns.

Willy

I use the same goop for horn dampening. You can also use gravel guard. I buy the stuff in bulk from an auto refinishing wholesaler. I use a schutz gun and air compressor to apply it. The material, once dried, takers a paint finish very well and does not out gas.

[Lee in Montreal]

Rubberized body protection. Also known as body shutz by German car owners.

Wurth makes some. Other brand available. Usually, you can get a fine or a coarse texture.

http://forums.pelicanparts.com/uploads2/wurth1ab1069128542.jpg

Lee

[NickH]

I think the roofing stuff is very similar to the car stuff. I know there is glass fiber in the roofing cement though. Thats probably the only difference. The solvents are more then likely the same.


Nick


Body Shutz eh. That funny.

[NickH]

Im now trying to get the honey do list cut down some. Im hoping to be able to work on these soon though. My wife wants to park her car in the garage. I told her I would have to finish the cabinet so she can.

Maybe if Im luck she'll buy that and let me work on these bad boys this wekend. But then again, I'm not that lucky, LOL.


But they are taking up a ton of space in the garage. Im hoping that ill be at a point to get them done afater the holidays. Time is just flying by and they aint going to finish themselfs.

[NickH]

Well I have one cabinet painted. I'm going to put in some insulation this weekend hopefully. On the subject of horn dampening, the roofing cement doesn't seem to be working. I've put quite a bit on and no change when I knock on them. Sucks but that the way it goes. I tested the stuff on 1/4 inch ply because I didn't have any 3/8 inch.

I'll try an fire up the laptop to get some pictures loaded soon.

[Ear4life]

Hello Nick!
Happy new year!

Glad to hear that progress is on again :) that is more than I can say about my horn project at the moment :(

About damping of the horns: A friend of mine told me to make a closed chamber behind the horn curves, and fill them with sand, and glue an extra layer of wood on the top. He has done it to his Altec cabs, and they are soooo dead when you knock on them!! I have not don it to mine "yet" (my wheels underneath can not carry the extra load)

Best regards
Martin

[intercity125]

Hello Nick!
Happy new year!

Glad to hear that progress is on again :) that is more than I can say about my horn project at the moment :(

About damping of the horns: A friend of mine told me to make a closed chamber behind the horn curves, and fill them with sand, and glue an extra layer of wood on the top. He has done it to his Altec cabs, and they are soooo dead when you knock on them!! I have not don it to mine "yet" (my wheels underneath can not carry the extra load)

Best regards
Martin


Hi Martin,

One could also build the same box and fill it with a dense closed cell foam to stop the ringing. The idea is to completely fill the box and cushion the horn against any vibrations. Perhaps not quite as dead as using sand, but it sure keeps the weight down.

Nick,

Looking forward to the pics of your painted Altec... Happy New Year!

Willy

[NickH]

A buddy of mine said that too. It an awful lot of weight to add to it. I've got a few more idea to try though. I was going to get some adhesive backed hard felt and put it on the flares.

The tar is doing some just needs more. But its more then I want to put on there. Plus its not very easy getting in there.

Nick

[NickH]

57843


Got one up and running. Im now playing around with the horns. Sounds good so far though. Got the first coat of paint on the second cabinet last night. Hoping to get the second coat on tonight and get it moved this weekend. It would be nice to have stereo sound and not mono.

[intercity125]

57843


Got one up and running. Im now playing around with the horns. Sounds good so far though. Got the first coat of paint on the second cabinet last night. Hoping to get the second coat on tonight and get it moved this weekend. It would be nice to have stereo sound and not mono.


Looking good, Nick!

Okay, got a couple of questions... what type of paint did you use on the cabinets? I've been thinking about going the paint verses veneer route on my horn project, too. Also, I see that you have a (ribbon?) tweeter atop the cabinet; are you running it as a "super tweeter" connected in series with the mid/horn, or do you have a three-way crossover? Thanks!

Willy

[NickH]

Behr brand paint and the color is dark granite. Behr is home depots brand of paint I believe. At the moment the tweet is crossed in at 5 k. But I'm just using a beater parts express cross over until I get all my parts from erse.
They will be crossed in at 7k on the crossover I'm building and its a linkwitz alignment.

Still waiting to put a second coat on the other cabinet. Been to cold to paint the last few days. I'm hoping I'll get it done this weekend or I'm buying a heater.

Nick

P.S. Its a fountek ribbon. Neocd 2.0 I think. They were damn near 200 bucks a pop when I bought them. Price dropped right after I bought them to around 100 a pop. Go figure.

[Ear4life]

Hey Nick!

Nicely done! I hope you have the other speaker up and run soon! Still happy about the sound? I had to do a lot of tweaking in the crossover before mine became "right". Do you like the Fountek ribbon? I have the Neo Pro 5I laying around just waiting for me to start working on the crossover.

Best regards
Martin

[intercity125]

Behr brand paint and the color is dark granite. Behr is home depots brand of paint I believe. At the moment the tweet is crossed in at 5 k. But I'm just using a beater parts express cross over until I get all my parts from erse.
They will be crossed in at 7k on the crossover I'm building and its a linkwitz alignment.

Still waiting to put a second coat on the other cabinet. Been to cold to paint the last few days. I'm hoping I'll get it done this weekend or I'm buying a heater.

Nick

P.S. Its a fountek ribbon. Neocd 2.0 I think. They were damn near 200 bucks a pop when I bought them. Price dropped right after I bought them to around 100 a pop. Go figure.

Hi Nick,

Thanks for the information on the paint. The color suits the cabinets very well. At the moment I only have the 511B horns and a pair of rebuilt Altec N501-8B crossovers. I had been entertaining the thought of adding a pair Fostex, Air Motion, or Fountek tweeters in series just to complement the horns, but now that I have seen your project I am wondering if I should just go with a true three-way crossover from ALK or GR Research. Hmm, jury's still out, but I am digging your's at the moment and can't wait to hear your thoughts on the final product. Cheers!

Willy

[NickH]

Last night I did something different last night. I hooked a jbl 3115a crossover to it. Its a 2 way 500hz cross with cd compensation. Huge difference. I did 2 different things with the tweet. I have 2 I tried the ribbon plus a Jensen r106. I just use a cap I had on hand for a 1st order cross. I have to say I'm digging it. I'm trying to get my hands on a jbl 3110a which is a 800 us cross with cd comp.

as for the changed bass reflex tuning, I'm waiting on having stereo before making my decision on it. But it seems to work pretty well.

I can tell you this, even in mono listening to classical music. I can close my eyes an I'm in front of a. Orchestra.

All in all I'm quite happy. Just waiting on a day where the temp is above 50 so I can get the last coat of paint on.

Nick



Hi Nick,

Thanks for the information on the paint. The color suits the cabinets very well. At the moment I only have the 511B horns and a pair of rebuilt Altec N501-8B crossovers. I had been entertaining the thought of adding a pair Fostex, Air Motion, or Fountek tweeters in series just to complement the horns, but now that I have seen your project I am wondering if I should just go with a true three-way crossover from ALK or GR Research. Hmm, jury's still out, but I am digging your's at the moment and can't wait to hear your thoughts on the final product. Cheers!

Willy

[intercity125]

Last night I did something different last night. I hooked a jbl 3115a crossover to it. Its a 2 way 500hz cross with cd compensation. Huge difference. I did 2 different things with the tweet. I have 2 I tried the ribbon plus a Jensen r106. I just use a cap I had on hand for a 1st order cross. I have to say I'm digging it. I'm trying to get my hands on a jbl 3110a which is a 800 us cross with cd comp.

as for the changed bass reflex tuning, I'm waiting on having stereo before making my decision on it. But it seems to work pretty well.

I can tell you this, even in mono listening to classical music. I can close my eyes an I'm in front of a. Orchestra.

All in all I'm quite happy. Just waiting on a day where the temp is above 50 so I can get the last coat of paint on.

Nick

Hi Nick,

No kidding! I've had to put my KEF 105 project on hold because it has been too darn cold out in the garage to do anything. I just have to apply and trim route the final edge-banding, then I can begin on the Altec's. Tomorrow (Sun) is supposed to be a fairly warm day so, perhaps, I can knock those out.

Glad to hear that the JBL 3115a's have made a big difference. I'll give my N501's a try and see what happens. I still like the idea of a full-range two-way, but the main goal is to get them sounding great no matter what.

Yeah, there's nothing like a pair of big Altec's (or K-Horns) to give you that "you are there" music experience. A good friend of mine who lives in town has a pair of K-Horns, being driven by tubes, and I just marvel at the sound every time I hear them. I hope my Onken/511B's sound just as good, if not better.

Willy

[NickH]

Yep, going in the right direction. I did leave out one important detail. The cheap 3 way cross from parts express is crossed at 800 at the low end and not 500.

Just wanted to let you know that.

Ya weather report is the same as yours here. I'm going to buy a little heater for the garage though. Just incase.

Nick




Hi Nick,

No kidding! I've had to put my KEF 105 project on hold because it has been too darn cold out in the garage to do anything. I just have to apply and trim route the final edge-banding, then I can begin on the Altec's. Tomorrow (Sun) is supposed to be a fairly warm day so, perhaps, I can knock those out.

Glad to hear that the JBL 3115a's have made a big difference. I'll give my N501's a try and see what happens. I still like the idea of a full-range two-way, but the main goal is to get them sounding great no matter what.

Yeah, there's nothing like a pair of big Altec's (or K-Horns) to give you that "you are there" music experience. A good friend of mine who lives in town has a pair of K-Horns, being driven by tubes, and I just marvel at the sound every time I hear them. I hope my Onken/511B's sound just as good, if not better.

Willy

[NickH]

Painting is done.:D

let it dry for a few days then put in some insulation. It will make its way upstairs in a couple days. Then I start building amps next.

Can't wait.

Nick

[NickH]

57913

Second cabinet is done and upstairs. I didnt have much time to play around last night. I just installed the woofer and soldered leads onto the cheap parts express crossovers. Plus insulated the cabinet.

I spent a few minutes listening. There was something odd going on. The volume was oscillating. I didnt have time to trouble shoot the problem since it was getting to be past my bed time. Im getting most of the parts for the crossover Im building tonight. The rest Ill have in a couple days. Im going with a low frequency of 550 hz. I picked 550 to get the closest value on the coils. And then 7000. Again its linkwitz.

Im going to cut a piece of wood to mount the tweeters on top of the horns. I also need to order 2 more l pads so I can play with the other tweeters I have. Namely some jensens which I really like. The have a much wider dispersion then the ribbons.


Nick

[Ear4life]

Hey Nick!

Good job! They are looking very nice! :)

When it comes to the impedance curve of a speaker, it is changing a lot over the frequencies, and those "universal" filters will most likely not give a good result. It will help you if you have a measure microphone, to see how fare the theory is from the real world, when you are trying different values in the crossover ;)
Remember, it is not the DC, or "Z" impedance of the driver, but the impedance curve that often appears along with the response curve, you have to use when making crossovers.

Best regards
Martin

[NickH]

Hi Martin,

Ya I know. Its just a temporary. Ive got almost all the parts I need to build them. Just waiting on 4 more inductors. I dont have a measurement mic but Im thinking about ordering 1 next week.

How could you use the impedance curve to calculate the component values for a crossover? The impedance is never constant. Not saying it cant be done. Im just saying I dont know how to do it. But I know there will be a lot of trial and error. Doubt Ill get it right the first time I put it together.

Thanks,
Nick




Hey Nick!

Good job! They are looking very nice! :)

When it comes to the impedance curve of a speaker, it is changing a lot over the frequencies, and those "universal" filters will most likely not give a good result. It will help you if you have a measure microphone, to see how fare the theory is from the real world, when you are trying different values in the crossover ;)
Remember, it is not the DC, or "Z" impedance of the driver, but the impedance curve that often appears along with the response curve, you have to use when making crossovers.

Best regards
Martin

[Ear4life]

Hi Nick

Start with picking a crossover frequency. Then look at the impedance curve, and see what it shows at that specific frequency. It might be 6 or 10 ohm or something else. And that value should be used along with crossover frequency to calculate the components :) (this is how it works in theory) But it takes a mic to make the best result, it can also be a very good leaning experiences.

Best regards
Martin

[NickH]

I feel stupid now. I should have thought of that. But anyway, I'll be increasing the crossover frequency in the future so I will use that method. I need to get something to measure it though.


I had the tester parts express sells but it died. I need to buy some testing toys. A measurement mic too.

Nick




Hi Nick

Start with picking a crossover frequency. Then look at the impedance curve, and see what it shows at that specific frequency. It might be 6 or 10 ohm or something else. And that value should be used along with crossover frequency to calculate the components :) (this is how it works in theory) But it takes a mic to make the best result, it can also be a very good leaning experiences.

Best regards
Martin

[NickH]

Had an eventful weekend. I spent some time with the jensen tweeters connected to the speakers. I was very pleased with the sound. They only go up to 15k, and Im sure it starts to roll off way before that. But they just are so easy to listen too. Then I thought to switch the ribbons back in. Man what a big change. I was hearing a shimmer on cymbals that I just wasn't hearing before. Im in a tough spot as they both and very nice qualities.

But I have decided that I need to try some jbl tweeters on them. Im thining either 2404's or 2405's. I want to keep they 3 way otherwise I would just use both the jensen and fountek tweeters. But as with ribbons, there lasers.

I also for kicks hooked them to a little class d amp. It pushes max 5 watts at 8 ohms. Im quite surprised. But its was a duh moment. All my audio friend where telling me that you dont need much over 10 watts with them. I knew they were efficient, but I just needed to show my self how efficient they really are.

Ive got a dynakit st35 that will be running them for a bit. I just have to figure out a little issue with it. The power tubes are not seeing any bias voltage. But once it's up and running they should be pretty good driving them until I finish the next amp im working on. Its a triode mode class a push pull kt120 amp. It will probably only produce about 10 watts. Maybe a little more if im lucky. But it should work pretty well at driving them until I build a single ended gm 70 amp.

I did get my thorens td 124 working and hooked it up to them. A buddy of mine came over. He love's the song inagaddadavida so I put on the record. I had my emotive amp hooked to them at the time. It produces 125 watts rms. I crank the you know what out of it at the drum solo. It was soooo freaking loud. MY GOSH. I know I lost some hearing on that one. I've been to concerts that were more quite. But I torned it down pretty quick. The jensens were on top and I doubt that can handle more then a watt or 2. The speakers they were on were only rated at 30 watts total.


But for an impromptu setup it sounds really good. Everyone who hears is say wow. But no audiophiles have heard it. Im sure it would be picked apart. Once the crossovers are built it will improve quite a bit.


Nick

[sbjacob]

Had an eventful weekend. I spent some time with the jensen tweeters connected to the speakers. I was very pleased with the sound. They only go up to 15k, and Im sure it starts to roll off way before that. But they just are so easy to listen too. Then I thought to switch the ribbons back in. Man what a big change. I was hearing a shimmer on cymbals that I just wasn't hearing before. Im in a tough spot as they both and very nice qualities.

But I have decided that I need to try some jbl tweeters on them. Im thining either 2404's or 2405's. I want to keep they 3 way otherwise I would just use both the jensen and fountek tweeters. But as with ribbons, there lasers.

I also for kicks hooked them to a little class d amp. It pushes max 5 watts at 8 ohms. Im quite surprised. But its was a duh moment. All my audio friend where telling me that you dont need much over 10 watts with them. I knew they were efficient, but I just needed to show my self how efficient they really are.

Ive got a dynakit st35 that will be running them for a bit. I just have to figure out a little issue with it. The power tubes are not seeing any bias voltage. But once it's up and running they should be pretty good driving them until I finish the next amp im working on. Its a triode mode class a push pull kt120 amp. It will probably only produce about 10 watts. Maybe a little more if im lucky. But it should work pretty well at driving them until I build a single ended gm 70 amp.

I did get my thorens td 124 working and hooked it up to them. A buddy of mine came over. He love's the song inagaddadavida so I put on the record. I had my emotive amp hooked to them at the time. It produces 125 watts rms. I crank the you know what out of it at the drum solo. It was soooo freaking loud. MY GOSH. I know I lost some hearing on that one. I've been to concerts that were more quite. But I torned it down pretty quick. The jensens were on top and I doubt that can handle more then a watt or 2. The speakers they were on were only rated at 30 watts total.


But for an impromptu setup it sounds really good. Everyone who hears is say wow. But no audiophiles have heard it. Im sure it would be picked apart. Once the crossovers are built it will improve quite a bit.


Nick
Nice work I have the JBL2404 baby cheek tweeters on my A7's a very nice match I also added a BBE sonic maximizer to my A7 setup and it really helps more on the LF .

[intercity125]

Hi Nick,

The speakers have really come along nicely, and it sounds like you are well on your way to finding the correct crossover points to suit your tastes. I wanted to ask about the modified reflex port and how it has affected the bass response. Not sure if you had heard the speakers before the mod, but I am curious to know if the bass response had a noticable improvement after the mod? I've also seen where some have closed in the cabinet completely and not used a port, at all. I'd sure appreciate your thoughts on the matter whenever you get the time. Thanks!

Willy

[NickH]

Hey Willy,

Yep went thru the process of charting the 416's impedance versus frequency. It changes quite a bit. I put a zobel network on it in the end. After all that work I have decided its just easier to go active. Im in the process of building a 3 way tube active crossover with a summed output below 100 hz for the subwoofer.. But I am thinking about still using a passive crossover for the mids to tweeters still. I havent made my mind up completely. I did on the other hand fix one problem with the st35 amp Im going to use on them. But I created another problem. I need to rewire the grounds on the amp. There are too many and its created a ground loop. So lots of hum.

Oh in regardes to the changes reflex tuning. Its not bad but not perfect. No matter what you do, they will always have a 6 db drop below 100hz. Thats why Im going the subwoofer route.
But progress is being made.

Nick





Hi Nick,

The speakers have really come along nicely, and it sounds like you are well on your way to finding the correct crossover points to suit your tastes. I wanted to ask about the modified reflex port and how it has affected the bass response. Not sure if you had heard the speakers before the mod, but I am curious to know if the bass response had a noticable improvement after the mod? I've also seen where some have closed in the cabinet completely and not used a port, at all. I'd sure appreciate your thoughts on the matter whenever you get the time. Thanks!

Willy

[intercity125]

Hey Nick,

Thanks for the info. Active is a great way to go, as there is so much flexibility and choice when it comes to slopes and cut-offs; the combinations are virtually endless.

The reason I asked about your port mod is because I have a chance to purchase a pair of A-7 cabinets, verses making a pair of Onken enclosures myself. I wasn't looking forward to the build, but I do like the design. The A-7's, on the other hand, will need a bit of TLC and I would, most likely, do a port mod on them, as well, but that's the fun of it.

I just have to decide which way to go.

Willy

[Ear4life]

Hello guys!

Nick: To make a very good passive crossover isn´t easy. So going with active crossover gives other opportunities and advantages as well. And it is easy to try out new components :bouncy: Keep it up!! :D

Willy: It is a must to create a real bass reflex rather than just one big hole :blink: especially if used at home (just where we want it!!) , it will extend the response in the low end as if it was different speaker. The Altec A7 / 828 cabinet does sounds very good, and has good internal volume. Most of the music-people I know prefer the A7/828 over the Onken for different reasons. What I really like about the 828 is that you can match the time domain of the bass driver and the compression driver on top very well.

Best regards
Martin

[intercity125]

Hi Martin,

I will, most likely, opt for the 828 cabinets simply because they are complete and need the least amount of work to get them done. I will still go through them with a fine-tooth comb, as my better half expects nothing less if they are going to be used in the house!

I've heard 828's (A-7 500's) on a couple of occasions and agree with your comment that they sound very good. I've just never heard a pair that someone has tweaked, if you will. Regarding the Onken, I have neither seen nor heard a pair, I just like the design aspect of them. I will be looking at the 828 cabinets, hopefully, this weekend, so I will report back and let you know how it went. Cheers!

Willy

[NickH]

Hello Gentlemen,

Didn't get much done this weekend. Have to get my garage organized. I started playing around with trying to diy some smith horns. But I think I'm going to hold off. I've got 3 2 by 4 foot sheets of 3/4 inch bb ply. I think I'm going to go full altec. Yep I'm going to put on some wings. I still want to try to diy some smiths but right now I'm still really digging these 2380 copies.

As for the wings I'm not going to go crazy. I figure a foot on the top and sides should do it. Plus my wife really wants the horns mounted in a baffle. The wings are supposed to really help the bass response.

I'm also thinking about putting a sub together. I've got a 7cuft cabinet that I built a while ago. I'm going to get 2 parts express 15" woofer and throw'em in there. I've got a 300 watt 2 channel amp to drive them for now. I'm going to run them from 2 100hz summed low pass active filters. Not going to run any equalization at first. Just run them straight.

Hey Willy. Okens are very nice. But the 416 is not the best driver for them. It will work though. The ultimate in onken driver is the 515. A very good friend runs onkens with iconic 515's in them. Though iconic calls them by another name. They are not the easiest to implement. The impedance of everything has to be taken into consideration. But your patience will be rewarded with stellar performance. But I would say that these 828's come in a pretty close second. But the onkens do a tad better in the bass department. But not much below 35 to 40 Hz. A sub still helps.

As for my crossovers they will still be analog. Plus I'm still going to use Passive crossovers between the mids and tweeters. I just wanted to have a separate amp for the woofers.

the crossovers are tube. Bass is fourth order sallen key and the woofer to mid tweet is 3 second orders in series.

For now I'm not going to bother with time alignment.

More later. Now I've got some John Williams to listen to.

Nick

[fpitas]

On the subject of damping the 511, here's my $0.02:

http://www.diyaudio.com/forums/multi-way/102329-horn-damping-9.html#post3060342

A skeptical friend repeated my procedure with similar results; no ringing, and to his surprise a much better sounding horn. This despite his horn being solidly mounted to a baffle board, with a good gasket.

Besides damping the ringing, I think the horn also needed to be reinforced against vibration in many spots, especially the bells.

BTW, later I discovered that "cocooning" the rear of the horn using the polyurethane adhesive, behind the flange back to the neck, made a small difference. Once again I think sound was radiating from the horn from vibration. The experience has made me appreciate why TAD, for example, starting making their horns out of solid or laminated wood, with thick wall sections everywhere.

[NickH]

Hi Fpitas,

Thatnks for the info. We arent actually talking about the 511 horn flares. I was trying to dampen the horn flares on the 828 bass horn. But this might be usalble here too. Ill check it out. Thanks.

Nick



On the subject of damping the 511, here's my $0.02:

http://www.diyaudio.com/forums/multi-way/102329-horn-damping-9.html#post3060342

A skeptical friend repeated my procedure with similar results; no ringing, and to his surprise a much better sounding horn. This despite his horn being solidly mounted to a baffle board, with a good gasket.

Besides damping the ringing, I think the horn also needed to be reinforced against vibration in many spots, especially the bells.

BTW, later I discovered that "cocooning" the rear of the horn using the polyurethane adhesive, behind the flange back to the neck, made a small difference. Once again I think sound was radiating from the horn from vibration. The experience has made me appreciate why TAD, for example, starting making their horns out of solid or laminated wood, with thick wall sections everywhere.

[fpitas]

Oops :o: My reading comprehension fail.


Hi Fpitas,

Thatnks for the info. We arent actually talking about the 511 horn flares. I was trying to dampen the horn flares on the 828 bass horn. But this might be usalble here too. Ill check it out. Thanks.

Nick

[NickH]

No problem.


Oops :o: My reading comprehension fail.

[NickH]

Well I think Im going to move on to another altec bass cabinet. I like the 828's, but I want to build. Im going to try and build a pair of either 817's 815's.

I dont have 2 more 416's to populate them so Im going to try out parts express 15" pro driver. The ts parameters are in between the ts parameters of the gpa 416 and the 515. Im thinking Ill build a pair of half width jbl 4520's and put the 416's in them for the below 50 crowd.

I'm thinking the 817 will be a better fit. Threw my door ways that is, LOL. Ive read the 815 is a little large for normal doorway width. I'm hoping to start build wood soon. Ive got a none audio toy to pay off first though then its gung hoo.


Nick

[intercity125]

Well I think Im going to move on to another altec bass cabinet. I like the 828's, but I want to build. Im going to try and build a pair of either 817's 815's.

I dont have 2 more 416's to populate them so Im going to try out parts express 15" pro driver. The ts parameters are in between the ts parameters of the gpa 416 and the 515. Im thinking Ill build a pair of half width jbl 4520's and put the 416's in them for the below 50 crowd.

I'm thinking the 817 will be a better fit. Threw my door ways that is, LOL. Ive read the 815 is a little large for normal doorway width. I'm hoping to start build wood soon. Ive got a none audio toy to pay off first though then its gung hoo.


Nick

Hey Nick,

What's up? Did all that Onken build talk over on my thread get your juices flowing? LOL! On a serious note, the 517 is a great cabinet, and a great looking cabinet, too. It's a tough build, what with its flare and side vents, but the rewards are worth the effort.

Regarding that pro 15, I say go for it. We installed Peavey Low Rider 15's in a friends La Scala's and the bass was unbelievable. We did this blind, without regard to the ts parameters or anything, just a one for one swap and they sound awesome. Just food for thought.

Willy

[NickH]

Hey Willy,

Sure did. Nah just kidding. I was thinking about building a pair of these before I got the 829's. I figure if I take my time I can build anything. What helps speed things up is I use a brad gun. And it won't be done the same way altec did it.

I was also thinking about buying a pair of 421's and having them reconed as 416s. Or I could just buy 2 more. But there not the cheapest speakers. Hence trying the pe drivers. But I think with enough time and patience I can build them. I hope, lol.

Nick



Hey Nick,

What's up? Did all that Onken build talk over on my thread get your juices flowing? LOL! On a serious note, the 517 is a great cabinet, and a great looking cabinet, too. It's a tough build, what with its flare and side vents, but the rewards are worth the effort.

Regarding that pro 15, I say go for it. We installed Peavey Low Rider 15's in a friends La Scala's and the bass was unbelievable. We did this blind, without regard to the ts parameters or anything, just a one for one swap and they sound awesome. Just food for thought.

Willy

[intercity125]

Hey Willy,

Sure did. Nah just kidding. I was thinking about building a pair of these before I got the 829's. I figure if I take my time I can build anything. What helps speed things up is I use a brad gun. And it won't be done the same way altec did it.

I was also thinking about buying a pair of 421's and having them reconed as 416s. Or I could just buy 2 more. But there not the cheapest speakers. Hence trying the pe drivers. But I think with enough time and patience I can build them. I hope, lol.

Nick

Hi Nick,

A Brad gun is a very handy tool when it comes to cabinet construction. It keeps things aligned while glue sets up, and it allows you to add screws later without fear of things shifting around. The traces are easy to fill as the holes are so darn small, and it just speeds things along. Great tool.

I'll let you in on one of my trade secrets (lol), and the way I will be building my Onken enclosures... the Dowelmax. This in an indispensible tool for making deadly acccurate, and strong, joints in wood without the need of nails or screws. You simply drill the holes using the Dowelmax jig, add glue and the dowels, and clamp things down. The joint will never slip and you needn't worry about filling in holes afterwards. You can certainly add screws if you choose, but it is not necessary. Check out the Youtube demo's, as they can explain things far better than I.

How would the JBL 2225H work in a 517 cabinet? It's got some impressive specs, and can be had for reasonable costs, though I admit not having bumped its TSP's against the 517. It is one of the choices I may use in the Onken if I don't go with the GPA-515.

Willy

[NickH]

Ill check out the dowelmax. Sounds like something you would hear about on an infomercial. Your the second person who mentioned using dowels. Ill give it a try. Oddly enough the 2225 is one of the optional drivers im looking at. I have the 2 416 so Im thinking to just get 2 more. 418's and 421's are easy enough to score on ebay. They can be converted into 416. And when they are alnico magnets the the same. Just charged differently.

Ill just go with my original route and build a reflex subwoofer. Besides I would be pushing it with the 817 alone. Adding a 4520 and I think my wife may draw the line.




Hi Nick,

A Brad gun is a very handy tool when it comes to cabinet construction. It keeps things aligned while glue sets up, and it allows you to add screws later without fear of things shifting around. The traces are easy to fill as the holes are so darn small, and it just speeds things along. Great tool.

I'll let you in on one of my trade secrets (lol), and the way I will be building my Onken enclosures... the Dowelmax. This in an indispensible tool for making deadly acccurate, and strong, joints in wood without the need of nails or screws. You simply drill the holes using the Dowelmax jig, add glue and the dowels, and clamp things down. The joint will never slip and you needn't worry about filling in holes afterwards. You can certainly add screws if you choose, but it is not necessary. Check out the Youtube demo's, as they can explain things far better than I.

How would the JBL 2225H work in a 517 cabinet? It's got some impressive specs, and can be had for reasonable costs, though I admit not having bumped its TSP's against the 517. It is one of the choices I may use in the Onken if I don't go with the GPA-515.

Willy

[NickH]

Holy crap that things expensive. That cost more then a gpa 416-8c.

I think I will stick with pl adhesive and a trusty brad gun. Maybe some screws too.


Nick

[intercity125]

Holy crap that things expensive. That cost more then a gpa 416-8c.

I think I will stick with pl adhesive and a trusty brad gun. Maybe some screws too.


Nick

LOL! Yes, it is. I got mine early on, when they had a sale, so it wasn't too bad. They do make a "JR." version that does many of the things the Dowelmax does, but it is still $99.00.

Let us know what cabinet you decide to go with.

Does this mean you have scrapped the wing project? Just curious.

[NickH]

300 wouldnt be bad if it was a power tool. I just think its a little steep for what it is. 99 bucks is much better. For now yes the wings are scrapped. I will proceed once the 817 cabinets are built and maybe try it on them.

Im thinking about investing in a biscuit joiner. Harbor frieght has one. If I did a ton of wood working I would probably buy a real nice one. But since I dont. Ive bought quite a few of there power tools. They have worked out fine for me. If I started doing this more I would probable upgrade to something better.



LOL! Yes, it is. I got mine early on, when they had a sale, so it wasn't too bad. They do make a "JR." version that does many of the things the Dowelmax does, but it is still $99.00.

Let us know what cabinet you decide to go with.

Does this mean you have scrapped the wing project? Just curious.

[NickH]

I think I'll just buy 2 more GPA 416-8b drivers for the 817.

[NickH]

I am re visiting the 815. Maybe with a little unique engineering I can make it doable in the house. Namely remove the back chamber portion so its just the horn. I will attache the back chamber when I have it up stairs. Just use so duct seal or something similar to make it air tight when I install it. I bought 2 sheets of 3/4 inch mdf last night to make the horns out of. I also have some 2' / 4' sheets of 3/4" birch ply to use. I think at first Im going to try the parts express woofers. And bought 2 more 416's at a latter date.

The nice thing about making the back chamber removable is I can experiment with different size ones. Other then that Ill keep the throat size siz the standard altec dimensions. The horn length will be 24 inches and the moth width will be 48. Should be a fun little project.

Ill keep ya posted.

Nick

[intercity125]

Hey Nick,

That's a pretty hefty project (in more ways than one!) but will be very nice when completed. I am just finishing up my KEF 105 restoration and will begin work on the Onken bass enclosures. I'll start a thread on the project for anyone who is interested. It's going to be slow going as I want to do them up right.

I still haven't joined the DIY Audio site, but I do plan to. And, thanks again for pointing out your friend out to me. Cheers!

Willy

[NickH]

Hey Willy,

Those kef 105's are cool looking speakers. Kinda like ess speakers. I'm currently in a stand still. I'm trying to decide how to proceed.I don't know if I'm going to make something like a 4530ish back horn for the lows. I might still build a single driver 815 for the mid bass or cut the bottoms off the 829's and use them. So many choices to make.

But at the moment I'm building 2 tube monoblocks. I've been working on these for awhile and I need to get them finished before anymore magic happens in the speaker department. But the gears are turning.

what drivers are you planning to use for the onkens?

Nick

[intercity125]

Hi Nick,

It's a tough decision with all the possible choices. I say throw caution to the wind and go with what your gut tells you, and, what will best suit your listening room. The right decision will spring forth.

Yeah, I love the 105's. They are true studio monitors and hold nothing back. I turn to them when I want to know exactly what's on a recording. Probably not fair to use them in the "home" environment, but I like my music to be honest, good, bad, or indifferent.

As for the Onken's, I've narrowed it down between two candidates for the drivers... the JBL 2226H or the GPA 515. Both are great for the Onken and share many similarities rather than differences, so it will probably come down to a matter of cost. The JBL's can be hideously expensive, but there is a gentleman here in town selling three of them for a very reasonable price. Then again, I haven't ruled out drivers from other manufactures as there are many good ones out there and probably at a lower cost than both the JBL's or GPA's.

On another note, I joined the DIY Audio site and sent a PM to your friend Kevin. Just waiting to hear back from him. Thanks again for his information.

Willy

[NickH]

Hey Willy,

The GPA 515 with the ceramic magnet is 300. The alnico is 550. Not cheap but there's not much that can compete with there performance.

You can get a pair of used 2226's for pretty cheap I imagine. I don't know much about them so I can't say how they would do. I know the 515 will work past 1khz quite well.

Good luck and I hope Kevin gets back to you. He's been very busy the last year. Its hit or miss hearing back from him. There are some real good guys other then him. I want to say either pano or gm are the other guys. I just don't remember which one.

I'm thinking I'm going to do a little of both. A single driver 815 and a modified 4530. Make them both the same height. I told my wife I'm making new cabinets that are smaller. Huh not, lol. They will be be 4 feet tall and probably 5 wide. I should have known better.


Nick




Hi Nick,

It's a tough decision with all the possible choices. I say throw caution to the wind and go with what your gut tells you, and, what will best suit your listening room. The right decision will spring forth.

Yeah, I love the 105's. They are true studio monitors and hold nothing back. I turn to them when I want to know exactly what's on a recording. Probably not fair to use them in the "home" environment, but I like my music to be honest, good, bad, or indifferent.

As for the Onken's, I've narrowed it down between two candidates for the drivers... the JBL 2226H or the GPA 515. Both are great for the Onken and share many similarities rather than differences, so it will probably come down to a matter of cost. The JBL's can be hideously expensive, but there is a gentleman here in town selling three of them for a very reasonable price. Then again, I haven't ruled out drivers from other manufactures as there are many good ones out there and probably at a lower cost than both the JBL's or GPA's.

On another note, I joined the DIY Audio site and sent a PM to your friend Kevin. Just waiting to hear back from him. Thanks again for his information.

Willy

[NickH]

Ok I finally settled on a bass horn. Im going ahead with building a pair of jbl 4520's. Oh and Im bought a biscuit joiner. Harbor frieght has a dowel drilling jig that I bought. The only problem its it only works on butt joints where the wood is in the same direction. So corners would be a bit tricky. Ive been wanting a biscuit joiners so I went ahead and ordered one. Im going by lowes tonight and get some more wood cut. Im using mdf for everything since its not going to be moved much.



Nick

[intercity125]

Hey Nick,

How's it going? Good choice on the 4520's. Nice design and shouldn't be (too) complicated to build. Are you going to use two drivers per cab or mod them to take a single, larger, driver? Just curious. Either way they should supply you will all the bass you'll ever need, and more. Good deal on the biscuit joiner. I've never used one but I know they are very popular among cabinet making enthusiasts. Sounds like you are set. When does the work begin?

The KEF's are done and making wonderful music, so now I can begin on the Onken/Altec project. I've labored over this concept in my mind, and on paper, for several weeks now and I have decided to break with tradition and construct the Onken's as sealed enclosures. Of course, this means I will have to use totally different drivers than the GPA 515's or JBL 2226H's, due to their lower EPB/QTS specs, but that's okay. There are plenty of drivers that will behave well in a sealed enclosure. Anyway, more on that in a separate thread.

Keep us posted on the 4520's, and don't forgrt to include pics. Are you going to continue the 4520's in this thread or begin a new one? Cheers!

Willy

[NickH]

Haha, they begin today. I cut all the sides and cut slots for biscuits. I'm also using confitmat screws. Now I'm going to start mapping out the horn vanes on one of the sides. The clamp it to the otherwise and drill a bunch of holes through both. The holes will be corresponding point of the internal panels. I'm going to use blocks of 1x2 finished pine to fasten the internal vanes too. Not sure how I'm going to do that assembly yet. But I'm taking my sweet time too minimise screw ups on my part.

I think I'll make 2 holes in the baffle and make a block off for a hole so I can run it with one driver. I had to go buy some pipe clamps though. I'm gluing to pieces of mdf together for the back panel but my big bar clamps weren't big enough. So off to home depot again. Got a 10 foot piece of black pipe and 2 pipe clamp kits. Had them cut the pipe in half and I'm good. I think I'm going to clean up the glue edge on the 2 back panels with my router table though. They are a little rough at the moment. I also need to decide what adhesive to use. I'm planning to try loctite's pl which I've read good things about. Its applied with a caulking gun and expands as it cures so its good for sealing up things.

These cabinets won't be perfect but they will hopefully do the job for a bit.

As for the harbor freight biscuit joiner, its not perfect. It has a lot of play in the fence but I've seemed to get the hang of it. As a starter tool its just fine. It doesn't produce cabinet shop perfect joints. But neither can I yet, lol.





Hey Nick,

How's it going? Good choice on the 4520's. Nice design and shouldn't be (too) complicated to build. Are you going to use two drivers per cab or mod them to take a single, larger, driver? Just curious. Either way they should supply you will all the bass you'll ever need, and more. Good deal on the biscuit joiner. I've never used one but I know they are very popular among cabinet making enthusiasts. Sounds like you are set. When does the work begin?

The KEF's are done and making wonderful music, so now I can begin on the Onken/Altec project. I've labored over this concept in my mind, and on paper, for several weeks now and I have decided to break with tradition and construct the Onken's as sealed enclosures. Of course, this means I will have to use totally different drivers than the GPA 515's or JBL 2226H's, due to their lower EPB/QTS specs, but that's okay. There are plenty of drivers that will behave well in a sealed enclosure. Anyway, more on that in a separate thread.

Keep us posted on the 4520's, and don't forgrt to include pics. Are you going to continue the 4520's in this thread or begin a new one? Cheers!

Willy

[intercity125]

Haha, they begin today. I cut all the sides and cut slots for biscuits. I'm also using confitmat screws. Now I'm going to start mapping out the horn vanes on one of the sides. The clamp it to the otherwise and drill a bunch of holes through both. The holes will be corresponding point of the internal panels. I'm going to use blocks of 1x2 finished pine to fasten the internal vanes too. Not sure how I'm going to do that assembly yet. But I'm taking my sweet time too minimise screw ups on my part.

I think I'll make 2 holes in the baffle and make a block off for a hole so I can run it with one driver. I had to go buy some pipe clamps though. I'm gluing to pieces of mdf together for the back panel but my big bar clamps weren't big enough. So off to home depot again. Got a 10 foot piece of black pipe and 2 pipe clamp kits. Had them cut the pipe in half and I'm good. I think I'm going to clean up the glue edge on the 2 back panels with my router table though. They are a little rough at the moment. I also need to decide what adhesive to use. I'm planning to try loctite's pl which I've read good things about. Its applied with a caulking gun and expands as it cures so its good for sealing up things.

These cabinets won't be perfect but they will hopefully do the job for a bit.

As for the harbor freight biscuit joiner, its not perfect. It has a lot of play in the fence but I've seemed to get the hang of it. As a starter tool its just fine. It doesn't produce cabinet shop perfect joints. But neither can I yet, lol.

Hey Nick,

Man, you don't waste any time, do you? LoL! Confirmat screws are a perfect choice for particle board and MDF applications. As for adhesives, I've been using Titebond III Ultimate Wood Glue for most of my woodworking projects and it works great. For something more heavy duty you can also use Titebond Provantage Interior & Exterior Wood Projects Adhesive. It, too, is applied with a caulking gun. Good stuff! Depending on how fast you need a set and cure rate they have many other adhesives to choose from, too. Just something else to consider.

Willy

[NickH]

Oh no, don't give me more choices, lol. Its been a busy weekend. But productive. I finished the frame for the first horn. Drew the pattern on on the inside of a side. Then drilled small holes threw that panel and into one I had clamped to the bottom of it and then I played connect the dots. I also did that to two other sheets for the second horn.

I did have to change the horn a little. My horn is a little thinner the the 4520 by 2 inches so I had to compensate for it. So some angles have changed. But its coming along.

Nick


Hey Nick,

Man, you don't waste any time, do you? LoL! Confirmat screws are a perfect choice for particle board and MDF applications. As for adhesives, I've been using Titebond III Ultimate Wood Glue for most of my woodworking projects and it works great. For something more heavy duty you can also use Titebond Provantage Interior & Exterior Wood Projects Adhesive. It, too, is applied with a caulking gun. Good stuff! Depending on how fast you need a set and cure rate they have many other adhesives to choose from, too. Just something else to consider.

Willy