Some photos of my 4345 clones

[just4kinks]

Yesterday a photography enthusiast friend of mine came over to take some pictures of my 4345 project. He thought the woodworking would make an interesting lighting project. The pictures came out great, and I'm thrilled with the progress on the cabinets! This is the first time they've been even partially assembled.

I have dozens of things to say about the project, but I'll let the pictures do most of the talking. Here are some answers to the inevitable questions:
- All panels are 1" B/BB Baltic Birch including the baffle.
- I cut the locking miter joint completely on the table saw. It was time consuming but I'm happy with how it turned out. That said I'll probably just use the router bit next time.
- The mid-bass box is sloped downwards slightly on the top to fit a larger compression driver.

I will upload some more pics of the construction later.

http://farm7.staticflickr.com/6213/6377823517_65d03be9f7_b.jpg

http://farm7.staticflickr.com/6105/6377823879_8313b31575_b.jpg

http://farm7.staticflickr.com/6057/6377824205_de5def78e1_b.jpg

http://farm7.staticflickr.com/6214/6377824511_9c5f45b5cb_b.jpg

http://farm7.staticflickr.com/6039/6377824827_1bba6b364f_b.jpg

http://farm7.staticflickr.com/6235/6377825177_dfd615225d_b.jpg

http://farm7.staticflickr.com/6093/6377825543_55cdfdbb52_b.jpg

http://farm7.staticflickr.com/6114/6377825853_3687ef7c52_b.jpg

http://farm7.staticflickr.com/6213/6377826205_7925683d65_b.jpg

http://farm7.staticflickr.com/6237/6377826447_9e0d9f4108_b.jpg

[rdgrimes]

Love the joints. Nice work.

[4313B]

Outstanding!

I hope you enjoy them. :)

[Lee in Montreal]

Holy Batman. That's very impressive craftmanship here. :eek:

Please explain how you do the joints...

[Mr. Widget]

Love the joints. Nice work.Yeah, yeah... I was admiring the clamps! I have piles of "Pony" clamps and Jorgensen pipe clamps, but those Cabinet Masters look awesome! ;)

Great work, keep this pics coming!


Widget

[just4kinks]

Thanks everyone.

And 4313b, I owe you a debt of gratitude for all of your engineering that is behind these:

http://farm7.staticflickr.com/6211/6378329117_6282eefddb_b.jpg

Also thanks to JohnW who modified the l-pads and added the zobel. This is the circuit I used, with a few tweaks of my own:
http://www.audioheritage.org/vbulletin/showthread.php?314-4345-monitor-plans&p=122115&viewfull=1#post122115

Here is one of the boards after etching:
http://farm7.staticflickr.com/6113/6378328453_c912c63f07_b.jpg

[just4kinks]

Yeah, yeah... I was admiring the clamps! I have piles of "Pony" clamps and Jorgensen pipe clamps, but those Cabinet Masters look awesome! ;)


It's all because of the photography! I told my friend he should sell those photos to Jorgensen.



Please explain how you do the joints...

7 cuts on the table saw. 3 dadoes, 2 bevels, 2 straight cuts. The error compounds so extreme accuracy is required. Slight bowing of the panel or variation in the pressure holding the panel against the table or fence will ruin the joint. Like I said, I think I'll use the lock-miter router bit next time!

The hardest cut is the first one because you need to make a jig to hold the panel vertically:
http://farm7.staticflickr.com/6037/6378328789_d2825c9eba_b.jpg

Here are a couple other pics, showing the jointing of the midbass box:
http://farm7.staticflickr.com/6094/6378329463_c48f98c72e_b.jpg

I wanted to beef up the bracing over the stock design, but it was a tight fit! I was planning on more cross bracing and a sideways piece across the top, but there is just not enough room.http://farm7.staticflickr.com/6019/6378329713_3216d084e6_b.jpg

[Amnes]

Wow. The woodwork looks simply amazing! I haven't seen pics of a project here with neater cabinets at the stage yours are. The crossovers - man what gems. They look like '80's Japanese optics quality.

I must ask - may you post a picture of your drivers? Even ones shot with a towel will do. Also - are you a carpenter? Where did you get those skills? This thread made my day.


http://blog.ethicallyhip.com/files/File/props.jpg

[Lee in Montreal]

And 4313b, I owe you a debt of gratitude for all of your engineering that is behind these:

It looks like somebody spent all his monthly allowance at Solen. :D

[gferrell]

The obvious question is- WILL YOU MAKE ME A PAIR!

[Wardsweb]

Wow that is come clean work. You are a true craftsman. :applaud:

[richluvsound]

Inspiring ... Makes me want a pair ! like the Miller Tig rig in the background . Its wonderful to see a youngman with the desire to learn such wonderful skills and put them to use building the things of his dreams .... :applaud:

Rich

[charles cai]

good job:applaud:

[Hey19]

Thanks everyone.

And 4313b, I owe you a debt of gratitude for all of your engineering that is behind these:

http://farm7.staticflickr.com/6211/6378329117_6282eefddb_b.jpg

Also thanks to JohnW who modified the l-pads and added the zobel. This is the circuit I used, with a few tweaks of my own:
http://www.audioheritage.org/vbulletin/showthread.php?314-4345-monitor-plans&p=122115&viewfull=1#post122115

Here is one of the boards after etching:
http://farm7.staticflickr.com/6113/6378328453_c912c63f07_b.jpg

are those charge coupled networks?

[DavidF]

Love the joints. Nice work.

Ooooh yes. Precision tools, sharp blades and skilled hands. Very nice.

[just4kinks]

Thanks for the kind words, everyone. It means a lot coming from you guys. But really these are small accomplishments compared to some of the amazing creations I have seen from other forum members!



I must ask - may you post a picture of your drivers? Even ones shot with a towel will do. Also - are you a carpenter? Where did you get those skills? This thread made my day.


I will post a pic when I have them, currently they are being reconed by the one and only Edgewound. I will be using 2245h + 2122h + 2425j (for now) + 077.

And I'm no carpenter, just an enthusiast for all kinds of DIY. Anybody could do the same with enough patience and good tools.


It looks like somebody spent all his monthly allowance at Solen. :D

Please don't remind me! This project has been expensive at every turn.


like the Miller Tig rig in the background


Good eyes, I'm surprised you spotted it! Unfortunately it's just a MIG, I'd love to learn TIG but that's a project in itself.


are those charge coupled networks?

Yes, following 4313b's design and the schematic in the link. There is still a lot of work to be done, hopefully I will have more pics posted within the next couple weeks.

[1audiohack]

Good eyes, I'm surprised you spotted it! Unfortunately it's just a MIG, I'd love to learn TIG but that's a project in itself.

Judging by the personal skill you have displayed I doubt you will find it difficult, I personally don't find it any more demanding than any of the other common welding processes.

I however will be staring at my table saw this weekend wondering how to duplicate your precision joinery.;)

[richluvsound]

The whole world is a Mecchano set , but it looks like you have made huge strides with the toughest one
' WOOD '

You will enjoy that speaker . There is nothing better than hearing a speaker you've made .

This is the best DIY speaker forum in the world !

BTW ,when you can TIG aluminium over head ,you can weld . TIG welding stainless is easy by comparison ,but finishing it is a another ball game ... If you can gas weld ,you can Tig ... Practice

Rich

[Amnes]

just4kinks I must thank you again for starting this thread. It gave me some inspiration for what do and what to postpone in the near future (clonewise). I couldn't fit the big picture in my tunnelvision beforehand.

[Eaulive]

That is some really great work, you have all my respect. :applaud:

[rdgrimes]

OK, since we're all slathering him with priase, I think that just4kinks needs to step up and admit how many pieces of plywood were "re-purposed" in the course of this project. :D

[Amnes]

OK, since we're all slathering him with priase, I think that just4kinks needs to step up and admit how many pieces of plywood were "re-purposed" in the course of this project. :D

True! Show us the bin with bloody fingers too!

[richluvsound]

Ignore these guys.... there is more gripfill than wood in their speaker builds !

;)

[just4kinks]

OK, since we're all slathering him with priase, I think that just4kinks needs to step up and admit how many pieces of plywood were "re-purposed" in the course of this project. :D

Plenty! But let's call those the "test pieces" ;)

Luckily the bloody finger bin is still empty.

Seriously there were quite a few mistakes, mostly from being absent-minded. Some of them still make me sick to think about, even though I was able to repair. Oh well, if they were perfect now then I would only be more upset later on when the cat scratches them.

[rdgrimes]

Plenty! But let's call those the "test pieces" ;)


That's why I always start cutting the biggest bits first, so they can be made into smaller bits if circumstances call for it. ;)

That plywood can't be cheap, a mistake must hurt in more ways than one.


Ignore these guys.... there is more gripfill than wood in their speaker builds !

;)
I have it on good authority that wood filler has excellent sonic qualities.

[4313B]

That's why I always start cutting the biggest bits first, so they can be made into smaller bits if circumstances call for it.:applaud:

[badman]

Excellent work. That joinery is truly superb, though also truly excessive :) But nothing exceeds like excess!

[Uncle Paul]

Dang, that's excellent work all the way around! Can't wait to see how they turn out!

[DavidF]

Ignore these guys.... there is more gripfill than wood in their speaker builds !

;) Hey...hey. That's uncalled for. (can you buy gripfill in 5 gallon tins?)

[just4kinks]

They're starting to look like speakers! A bunch of friends came over this weekend to help me glue them. All the joints had to be glued in one shot, and the glue I used (Titebond Extend) has a 15 minute working time. Even with 6 people we were cutting it close! There is still a ton of work to be done, but this is a major milestone.

http://farm8.staticflickr.com/7144/6464017639_4ff1755cb3_b.jpg

http://farm8.staticflickr.com/7020/6464017357_849ef2fb8b_b.jpg

http://farm8.staticflickr.com/7008/6464017459_09ee943f1b_b.jpg

[BMWCCA]

Beautiful craftsmanship!
:applaud:

[just4kinks]

The network enclosures are starting to come together. I'll post a fully assembled picture after polyurethane.

Can you believe that my wife wants me to hide these behind the speakers?!?

http://farm8.staticflickr.com/7008/6490592497_33365e2d42_b.jpg

[just4kinks]

The grill frames are finished. I'm not very happy with them, the plywood was a little warped and it threw everything off.

http://farm8.staticflickr.com/7145/6508693121_c8be46d136_b.jpg

[rdgrimes]

The grill frames are finished. I'm not very happy with them, the plywood was a little warped and it threw everything off.



A little steam and clamp time won't fix it?

[just4kinks]

A little steam and clamp time won't fix it?

I could give it a try... does steam work on plywood?

[richluvsound]

Thats how we used to bend marine ply panels on boats hulls . The trick I have found is to take the warp slightly further in the opposite direction ...it will spring back a little . You can also wet the concave side , it will expand leaving the convexed side static .

Apply the water with a damp sponge . Be careful with steaming , you don't want to separate the adhesive .

Another way , looking at your pics . remove the top bead , clamp the ply do flat and then re-glue the top bead .
When I do them I don't use screws on the top bead , glue ,clamp and when dry I drill 1/8 hole and use a bamboo skewer dipped in glue , leave it slightly proud and pare back with a sharp chisel .
Good luck and remember , good carpenters make mistakes , very good ones can fix it without leaving a trace .

You have wonderful skills ,now comes the experience . Have faith, you have a genuine gift !

Rich

[bigyank]

Awesome job on the grills. I usually use MDF for my grills (1" double refined MDF) but have you thought about trying some Hickory instead of plywood? Still as others have said, you got some definite wood working game, well done!


The grill frames are finished. I'm not very happy with them, the plywood was a little warped and it threw everything off.

http://farm8.staticflickr.com/7145/6508693121_c8be46d136_b.jpg

[just4kinks]

The networks are done! I didn't want to leave anything to chance, so I took some measurements and plotted the results in Excel.

http://farm8.staticflickr.com/7004/6632728375_4b228ec4f2_b.jpg

http://farm8.staticflickr.com/7035/6632728991_05c8ae7c6f_b.jpg

Here are the stock 3145 voltage drives for comparison:
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=15381&stc=1&d=1146736579

Better than I expected!

Other updates:
I tried to straighten the grills with some steam. I made some progress but I didn't want to stress the plywood too much. They're pretty good now, I don't think they'll rattle or anything.

I'm done with finishing. I ended up using Minwax Polycrylic, sprayed with HVLP. It looks pretty good, I'll post some more pictures after I get the drivers (there seems to be a delay in obtaining the recone kits from JBL).

[Amnes]

I'm lovin the crossovers. Bummer on the recone part. Hopefully you'll get them soon. Can't wait to see the cabs.

[Wellsie]

just4kinks (http://www.audioheritage.org/vbulletin/member.php?5495-just4kinks) Beautiful boxes! I just had a simple question. Where did you get the boards etched? Wellsie

[just4kinks]

Thanks. I etched them myself... the boards are big (8"x12") and it's not cost effective to send them out. And I used really wide traces, so I wasn't too worried about accuracy. Really the only problem is the chemical disposal.

I actually exposed them in the sun on my driveway! I overexposed the first one and all the photoresist came off, so I used clear contact paper and cut out the traces with an x-acto knife. I shortened the exposure on the second board and it came out perfect. If I do many more I'll buy an exposure lamp.

[boputnam]

Hmm... San Jose. Not so far. I'd love to see these beauties in real size!

:coolness:

[just4kinks]

Sure, you can see them, but if you want to hear them you'll have to wait a month or two. I'm still waiting on the recones <sigh>.

[4313B]

Sure, you can see them, but if you want to hear them you'll have to wait a month or two. I'm still waiting on the recones <sigh>.I'm ashamed to say that he's waited longer than that for me to build him a pair of networks. :o:

[just4kinks]

It was a good weekend! My wife and I drove down to Southern California for the weekend, and picked up the recones along the way. Edgewound has done an incredible job, I hope they sound as good as they look!

http://farm6.staticflickr.com/5119/7061024335_99f1b02720_b.jpg

[richluvsound]

You are in for a real treat ..... :D Nice work Edge !

Rich

[edgewound]

It was a good weekend! My wife and I drove down to Southern California for the weekend, and picked up the recones along the way. Edgewound has done an incredible job, I hope they sound as good as they look!

http://farm6.staticflickr.com/5119/7061024335_99f1b02720_b.jpg

It's always my pleasure to meet Lansing Heritage members in person....Thanks, Joe. I hope you and your lovely wife had a nice time in SoCal, despite the typically awful holiday traffic.

I'm just sorry it took so long to get the kits for the 2245Hs...but they turned out nice, nonetheless.

Your craftsmanship on these cabinets is a work of art. The attention to detail is simply stunning.



You are in for a real treat ..... http://www.audioheritage.org/vbulletin/images/smilies/biggrin.gif Nice work Edge !

Rich

Thanks, Rich. Your work is always inspiring to see.

[boputnam]

I'm just sorry it took so long to get the kits for the 2245Hs...but they turned out nice, nonetheless.:applaud:

[just4kinks]

It's always my pleasure to meet Lansing Heritage members in person....Thanks, Joe. I hope you and your lovely wife had a nice time in SoCal, despite the typically awful holiday traffic.

I'm just sorry it took so long to get the kits for the 2245Hs...but they turned out nice, nonetheless.


It was nice to meet you too, Ken, as well as all the other LH members that have helped me through this project.

The 2245's did turn out nice, and the 2122's did too! I know the delay was out of your hands, don't worry about it.

[just4kinks]

I left work early yesterday to get these assembled. I am totally pleased! It was worth every minute and every penny, and I haven't even dialed in the crossovers yet. The 2245's are amazing, deep and tight bass.

Here are a few more pics:

Note the lack of grill velcro. I have neo magnets embedded in the baffle from behind. I was unsure if I should do this, because the magnets attract dust (and screwdrivers), but now I'm glad I did. The grill attachment is so easy. Turns out that I don't even need the grill guide pin, too bad I drilled it already. Otherwise the baffles would be completely clean.
http://farm8.staticflickr.com/7272/6919121698_799e8d8276_b.jpg

http://farm8.staticflickr.com/7249/7065201693_c4f69e2fa4_b.jpg

And here is a final shot of the corner, to show how it looks finished. I love Baltic birch!
http://farm8.staticflickr.com/7083/6919121442_955e0026c4_b.jpg

[4313B]

Love the color! Well done! :applaud:


The 2245's are amazing, deep and tight bass.Crazy aren't they? :) I wish I still had the twenty cubic feet available for a pair. :yes:

[yggdrasil]

Looking very good. I'm sure you'll enjoy many hours with them!

[Amnes]

Love the fresh recones. That + your craftsmanship makes those cabs stunning. How deep are those magnets how many and what is their size? I'd like to use the same grill mounting technique if I decide to build a second pair of 4344's finished to my taste.

Is the eq plugged into your chain? I'm experiencing quite a bit of boomyness from my 2235ers in the 80-300 range. If that eq is plugged in it seems you have a similar problem. I suspect the source of it to be from one or a combination of the following reasons:

1. Room response
2. New speaker surrounds
3. Inadequate internal damping

I can't do much about #1. #2 will take some time to figure out. #3 is the only hipothetical cause that can be worked with in my case. I 1" of sheep wool on the inside of the cabinets. Need to experiment a bit.

[4313B]

Other things to check.

4. LF too close to the floor. (LE14H, 136H/2231H, 2235H and 2245H didn't require boundary reinforcement while the 124H/2203H was a bit more forgiving)
5. Too much DCR in the LF filter inductor(s).
6. No fiberglass insulation. (Greg tunes his enclosures using fiberglass, if you don't use fiberglass you will need to re-tune and/or re-volume the enclosure accordingly.

Note that not using fiberglass isn't trivial, it changes the net effective volume of the enclosure and therefore the system tuning as well as driver loading.

[Amnes]

Sounds like #6 is my problem. I'm not a fan of fiberglass but if it's a must...

[4313B]

Possibly.

Easy enough to check.

Greg invariably used 1" fiberglass on all surfaces but the baffle.

It is icky to work with... I preferred the tuflex in the Bozaks but it didn't seem to work so well in stock JBL enclosures. :p

[JuniorJBL]

Very nice J4K!! Those truly are a "Statement" speaker system!! Enjoy.:D

[just4kinks]

How deep are those magnets how many and what is their size? I'd like to use the same grill mounting technique if I decide to build a second pair of 4344's finished to my taste.

They are pretty big, 3/4" diameter x 3/8" thick N52. I took a guess at the pulling force I needed, used an online calculator to get and idea of the size, and then bought the cheapest size that was comparable. They are set almost all the way into the baffle/grill, about 1/16" from the face, covered only by a ply or two. Grind the point off of your forstner bit, and double check the depth stop before you drill! They are secured with epoxy, and if I ever do it again I will cut an opening for the air to escape when they are inserted.

The dust attraction is a real problem, it will form a faint shadow and it doesn't clean easily.


Is the eq plugged into your chain? I'm experiencing quite a bit of boomyness from my 2235ers in the 80-300 range. If that eq is plugged in it seems you have a similar problem.

The EQ is not in the chain, the curve in the picture is left over from my old setup. I ran some pink noise through last night, and the response is pretty flat. I'm a bit surprised, even if the speakers are perfect I would have expected more room anomalies and inaccuracies in my cheapo RTA setup. Anyways I did locate a polarity problem, and there are a few small bumps and dips but nothing that seems significant compared to the problems I dealt with last time.

[Jonis]

The dust attraction is a real problem, it will form a faint shadow and it doesn't clean easily.


Beautiful on every account!!! Regarding the magnet secured frames-- I'm considering this on my next set. Would there be any downside to putting the magnet in the grill and the striker plate in the baffle to minimize the dust effects?

[just4kinks]

Beautiful on every account!!! Regarding the magnet secured frames-- I'm considering this on my next set. Would there be any downside to putting the magnet in the grill and the striker plate in the baffle to minimize the dust effects?

I used magnets in both the grill and baffle, but a single, bigger magnet in the grill and a striker plate in the baffle is a great idea.

[edgewound]

I left work early yesterday to get these assembled. I am totally pleased! It was worth every minute and every penny, and I haven't even dialed in the crossovers yet. The 2245's are amazing, deep and tight bass.

Here are a few more pics:

Note the lack of grill velcro. I have neo magnets embedded in the baffle from behind. I was unsure if I should do this, because the magnets attract dust (and screwdrivers), but now I'm glad I did. The grill attachment is so easy. Turns out that I don't even need the grill guide pin, too bad I drilled it already. Otherwise the baffles would be completely clean.
http://farm8.staticflickr.com/7272/6919121698_799e8d8276_b.jpg

http://farm8.staticflickr.com/7249/7065201693_c4f69e2fa4_b.jpg

And here is a final shot of the corner, to show how it looks finished. I love Baltic birch!
http://farm8.staticflickr.com/7083/6919121442_955e0026c4_b.jpg

Stunning craftsmanship. Love the Scandinavian style look...and the outboard networks.

Congrats on the gorgeous project. I bet the crossovers mounted outside the box improves the performance a bit by cutting down vibration.

[Titanium Dome]

Congratulations! Very nice work. :)

[moparfan]

The color helps it blend in so that it doesn't look like a huge 2001 monolith in the living room.

This is such fantastic workmanship.

[Krunchy]

They look really nice!
Having made some primitive pete style cd racks recently in makeshift circumstances w/a router I can really appreciate how meticulous your woodworking skills are.
Freshly reconed drivers is basically like having some brand new 4345's. They will bring many many years of pure pleasure.
Welcome to the club &.... enjoy the hell out of them. :cheers: :dancin: :banana: :rockon1: :rockon2: :homer:

BTW: did you put a finish on them, clear coat & what kind of music do you mainly listen to?

[boputnam]

... I did locate a polarity problem.What was that, and how did it manifest?

[just4kinks]

What was that, and how did it manifest?

Well, the 3145 is a 4-way with the upper 3 sections inverted WRT the woofer. Even when the biamp switch is engaged.

I am biamping, with a 3-way passive crossover, and I wasn't sure about the polarity so I decided to match the 3145, with the upper 3 sections inverted WRT the woofer. When I looked at it with the RTA, I saw a distinct dip at around 300Hz. I flipped the wires going into the crossover and it flattened out. Both channels were the same.

Now I'm wondering... given the phase characteristics of the 3-way crossover, should the top 2 sections be inverted instead?

Maybe I'm thinking about it too hard, I probably just screwed up the wiring somewhere.

[just4kinks]

Thanks guys!


The color helps it blend in so that it doesn't look like a huge 2001 monolith in the living room.


Too bad, "2001 monolith" is what I was going for! :D


BTW: did you put a finish on them, clear coat & what kind of music do you mainly listen to?

I sprayed them with Minwax Polycrylic. It came out alright, but I'll probably just stick with polyurethane next time (I avoided it this time because of the yellow tint).

As far as music goes, I like rock, but I listen to a little bit of everything. Mostly newer stuff, from the last 20 years or so.

[Mr. Widget]

Congratulations! Very nice work. :)My thoughts exactly! :bouncy:


Widget

[Mr. Widget]

I sprayed them with Minwax Polycrylic. It came out alright, but I'll probably just stick with polyurethane next time (I avoided it this time because of the yellow tint).I almost always use one of the water based urethanes when finishing light woods... the satin Polycrylic works pretty well and doesn't yellow.


Widget

[boputnam]

Well, the 3145 is a 4-way with the upper 3 sections inverted WRT the woofer. Even when the biamp switch is engaged.Correct.


I am biamping, with a 3-way passive crossover, and I wasn't sure about the polarity so I decided to match the 3145, with the upper 3 sections inverted WRT the woofer.Correct.


When I looked at it with the RTA, I saw a distinct dip at around 300Hz.Now that there, is interesting. The crossover from the 2245 to the 2122H is 290Hz - nominally where you've seen this anomaly with your measurement gear.


I flipped the wires going into the crossover and it flattened out. Both channels were the same.Interesting solution, but it might have dealt with the symptom and not the problem.


Now I'm wondering... given the phase characteristics of the 3-way crossover, should the top 2 sections be inverted instead?As we tend to say in these instances, "you can do whatever pleases", but this would be different from the OEM engineering.


Maybe I'm thinking about it too hard, I probably just screwed up the wiring somewhere.Possible.

Clearly, you're deeply steeped in all this. However, may I be so bold as to humbly ask :o: if you're aware of JBL's unique polarity convention? Unless you are, this could explain the anomaly (cancellation) you noted, right where you noted it. But, if, as I expect, I get enlightened by your reply, we'll have to dig a little deeper... :hmm:

[just4kinks]

Clearly, you're deeply steeped in all this. However, may I be so bold as to humbly ask :o: if you're aware of JBL's unique polarity convention? Unless you are, this could explain the anomaly (cancellation) you noted, right where you noted it. But, if, as I expect, I get enlightened by your reply, we'll have to dig a little deeper... :hmm:

If you mean positive on black, yes I am aware of it.



As we tend to say in these instances, "you can do whatever pleases", but this would be different from the OEM engineering.

This got me thinking, what did JBL do in the 3155? The answer is that all 4 sections have the same polarity:
http://www.jblproservice.com/pdf/Network Schematics/3155 Network.pdf (http://www.jblproservice.com/pdf/Network%20Schematics/3155%20Network.pdf)

I started searching for an explanation, and the answer has been in front of me the whole time:
http://www.audioheritage.org/vbulletin/showthread.php?23824-My-quot-New-quot-4345-Clones&p=240082&viewfull=1#post240082
http://www.audioheritage.org/vbulletin/showthread.php?23824-My-quot-New-quot-4345-Clones&p=240590&viewfull=1#post240590

Sorry, Mr. Widget, but I bet you knew it wouldn't be "for the last time" when you wrote that :D

[BMWCCA]

I started searching for an explanation, and the answer has been in front of me the whole time:
http://www.audioheritage.org/vbulletin/showthread.php?23824-My-quot-New-quot-4345-Clones&p=240082&viewfull=1#post240082
http://www.audioheritage.org/vbulletin/showthread.php?23824-My-quot-New-quot-4345-Clones&p=240590&viewfull=1#post240590

Sorry, Mr. Widget, but I bet you knew it wouldn't be "for the last time" when you wrote that :D

OMG. Not that thread again! :eek:

[boputnam]

If you mean positive on black, yes I am aware of it.I guessed you would. :) But it's all in how you use that knowledge... ;)


This got me thinking, what did JBL do in the 3155? The answer is that all 4 sections have the same polarity...Correct. But that is not what JBL did with the 3145.

I have not experienced the dip you described, and my networks are stock - so wiring is easy the OEM way. I'm suspicious that with your gorgeous networks and JBL's inverted polarity there is some unintended wiring snafu. But it doesn't matter, so long as you have resolved the anomaly and have your motors firing the way (i.e., direction) you want them to on (+) signal.


OMG. Not that thread again! :eek::applaud: It was good to re-read that stuff. 3-yrs ago... Whoa.

[DavidF]

Love the color! Well done! :applaud:

Crazy aren't they? :) I wish I still had the twenty cubic feet available for a pair. :yes:

The big-baffle enclosures are always appealing to me. An outmoded preference, no doubt. But an old-fart is as an old-fart does.

Very well done.

[maxwedge]

I think their ugly!




























NOT!!!!!!!!:mona_lisa:
Nice work:D

[Titanium Dome]

I think their ugly!




























NOT!!!!!!!!:mona_lisa:
Nice work:D


Dood, I was ready to drive to Concord and dump cold water on your head! That is, until I saw your bottom line. :rotfl:

[maxwedge]

Dood, I was ready to drive to Concord and dump cold water on your head! That is, until I saw your bottom line. :rotfl:
Watch out, I have quick reflexes and long arms!:p

All joking aside, just4kinks project came out REALLY NICE!

[just4kinks]

I think their ugly!




























NOT!!!!!!!!:mona_lisa:
Nice work:D

You are SO off my Christmas card list! (j/k, glad you like them)


I bet the crossovers mounted outside the box improves the performance a bit by cutting down vibration.

I've been thinking about this comment, and I can't imagine how vibration would have any effect on resistors or capacitors. But it does seem that physical movement of an air-coil inductor through its own magnetic field would induce a distortion. I wonder if it would be measurable or audible.




I have not experienced the dip you described, and my networks are stock - so wiring is easy the OEM way.

Interesting. I assume you are biamping? 4th order network?


I'm suspicious that with your gorgeous networks and JBL's inverted polarity there is some unintended wiring snafu.


Yes, that is very possible! Eventually I'll pull the woofer and check everything, but right now I'd rather just listen to them. :D

[boputnam]

Interesting. I assume you are biamping? 4th order network?Yeah, per my pm a few weeks back. Bryston 10B LR, custom, using for the 4345 crossover point but 4th-order slope. It really tightened-up the low-end. The 2245 is such a wonderfully tonal, low Q woofer, it's nice to leave it on it's own as much as possible.


...right now I'd rather just listen to them. :DI second that!

[just4kinks]

Yeah, per my pm a few weeks back. Bryston 10B LR, custom, using for the 4345 crossover point but 4th-order slope. It really tightened-up the low-end. The 2245 is such a wonderfully tonal, low Q woofer, it's nice to leave it on it's own as much as possible.

Cool. I wasn't sure if that was just a suggestion or something that you are using yourself as well. I think this will be my next project, the amplifier can wait.

[boputnam]

I think this will be my next project...:bouncy: IMO, excellent priority particularly wrt your beautious DIY crossover. Yum...

[just4kinks]

The 4345's are pretty much done, but I've been keeping myself busy working on this active crossover. It's coming along nicely, all that's really left is to drill the mounting holes in the chassis.

The design is pretty simple, pretty much straight out of Douglas Self's "The Design of Active Crossovers". I did the circuit / board design myself and I had the boards printed by BatchPCB. I'm working on a discrete version, but of course that is a much bigger project and who knows when it will be done.

Specs:
- 4th order Linkwitz Riley
- 290Hz fixed crossover point
- Active balanced I/O
- High tolerance metalized polypropylene film filter caps, metal film resistors, 5532 opamps

http://farm8.staticflickr.com/7225/7323816946_1651f6ce07_b.jpg

http://farm8.staticflickr.com/7096/7323816826_fb5d25c6e9_b.jpg

[Amnes]

My goodness, that x-over looks lovely! I have a set of similar 4th order opamp pcb's on the shelf - need to solder them up too. In the long run my aim is also to end up with a discrete design x-over.
Do you have any knowledge of an existing diy kit or at least some online documentation of a completed project? Designing one is out of my leauge. I know brystons are fully discrete, and Pass too, but buying a xover thats more expensive than my amps would be a bit of a misalliance. Anyway If you end up finishing the discrete design I'm sure you'd find many LH members interested as well as other loudspeaker diy nuts to be found on boards across the world.

[neskor]

For discrete active crossover which is very similar to Pass XVR1 you can check here:
http://www.diyaudio.com/forums/analog-line-level/27651-mox-active-crossover.html

[just4kinks]

The meat of the discrete project is designing an opamp. I was thinking it would be cool to design it so that the whole board can plug into a standard DIP8 opamp socket, using the same pinout as the 5532. Then I will upgrade the opamps in my cd player, receiver, equalizer, and so on, and I'll have a fully discrete signal chain without spending kilobucks. And it sounds like just what you're looking for, as an upgrade for your opamp crossover kit.

But I'm not going to make any promises until I at least have a working prototype :D

[Amnes]

So you are aiming towards designing dual discrete opamps and plugging them into your boards? Is that nearly everything that differents a discrete design from integrated op-amped?

[neskor]

The meat of the discrete project is designing an opamp. I was thinking it would be cool to design it so that the whole board can plug into a standard DIP8 opamp socket, using the same pinout as the 5532. Then I will upgrade the opamps in my cd player, receiver, equalizer, and so on, and I'll have a fully discrete signal chain without spending kilobucks. And it sounds like just what you're looking for, as an upgrade for your opamp crossover kit.

But I'm not going to make any promises until I at least have a working prototype :D

something like this?
55885

[just4kinks]

something like this?
55885

Yeah. It's not easy to have an idea that someone else hasn't had already :). I'm hoping I can make mine a bit smaller than those.


So you are aiming towards designing dual discrete opamps and plugging them into your boards? Is that nearly everything that differents a discrete design from integrated op-amped?

Discrete designs usually use higher rail voltages as well.

[just4kinks]

The crossover is done!

It is a noticeable upgrade from the m552. Midbass is more defined, bass and drums are sharper and clearer. Also there seems to be a bit more resolution in the highs.

It went together pretty much as planned. I messed up the gain structure, and I'm stuck with +6dB gain - I can fix it, but I'll have to order more parts. Also there was a defect in one of the PCB's copper layers, causing a short between traces. It was frustrating to track down - next time I need to inspect the boards more thoroughly before assembly.

So what's next? The discrete op-amp, power amps, or maybe back to the wood shop for a matching birch rack / tv table.

http://farm8.staticflickr.com/7079/7184054781_cdb7f41730_b.jpg

http://farm8.staticflickr.com/7078/7184055111_95a4deba03_b.jpg

[hjames]

Your work looks very nice - small, modular and straight-forward.
Nice cabinet too!

[JeffW]

Yeah, where did you get the little enclosure for the crossover?

[boputnam]

The crossover is done!:applaud:


It is a noticeable upgrade from the m552. Midbass is more defined, bass and drums are sharper and clearer. Also there seems to be a bit more resolution in the highs.Excellent. And, your observation is consistent with my urging, although that included you consider a Bryston 10B L-R. I never contemplated you'd build your own! But that's all you, Joe!


It went together pretty much as planned. I messed up the gain structure, and I'm stuck with +6dB gain - I can fix it, but I'll have to order more parts. I'm curious about the error...


Also there was a defect in one of the PCB's copper layers, causing a short between traces. It was frustrating to track down - next time I need to inspect the boards more thoroughly before assembly.How'd you find it with everything still soldered to the PCB's? Compared one to the other...? :hmm:


So what's next? The discrete op-amp, power amps, or maybe back to the wood shop for a matching birch rack / tv table.Smaart...?

[just4kinks]

Your work looks very nice - small, modular and straight-forward.
Nice cabinet too!

Thanks!


Yeah, where did you get the little enclosure for the crossover?

http://www.par-metal.com/

Their enclosures are really nice! Thick anodized front face, variety of sizes, and good prices.



I'm curious about the error...

Basically, the balanced output buffer is doubling the amplitude of the signal. At some point I had realized it would be a problem, but I forgot to correct for it until it was too late.


How'd you find it with everything still soldered to the PCB's? Compared one to the other...? :hmm:

Luckily the short was on the bottom! It still took a while to find, at first I thought it was a faulty component and I clipped a bunch of them out.


Smaart...?

Yes! I have some ideas I want to run by you, when the time comes.

[Amnes]

Lemme guess: 100nf + 3.92k? What a gem. When I grow up I want to be just as talented knowledgeable and resourcefull as just4kinks. Fabbing up proper quality products on your own is a great way of life. I'm holding my breath till you fire up the discrete balanced crossover. I'm sure it'll be a work of art. I'll hopefully be firing my 24db@340Hz single ended opamp crossover tomorrow - really similar desing to what you fabbed up. Hopefully it too will work some magic in the overall feel of my clones.

[just4kinks]

Lemme guess: 100nf + 3.92k?
exactly! With 1% metal film resistors, and 1% mkp1837 (polypropylene metallized film) caps.


What a gem. When I grow up I want to be just as talented knowledgeable and resourcefull as just4kinks. Fabbing up proper quality products on your own is a great way of life. I'm holding my breath till you fire up the discrete balanced crossover. I'm sure it'll be a work of art.

It's not talent and resource, it's just excessive free time! Besides, you have already proven your skills with your own beautiful clone project.


I'll hopefully be firing my 24db@340Hz single ended opamp crossover tomorrow - really similar desing to what you fabbed up. Hopefully it too will work some magic in the overall feel of my clones.

post some pics! I want to see your handiwork.

[Amnes]

My clone project required me nearly only to solder the passive crossover and screw in the drivers - not too much work at all. Carpentry is an art, ordering cabs is not.

[just4kinks]

I'm working on a discrete version, but of course that is a much bigger project and who knows when it will be done.


A couple of you have asked, and I finally have some progress to post: my discrete crossover is almost done!

I spent a lot of time earlier this year developing my discrete op-amp. It is completely BJT-based, with a class-A output stage. I probably won't make a plug-in version after all, there would be too many compromises and it's too hard to guarantee stability. So far I have designed a balanced I/O board and a Linkwitz-Riley filter board. Next will be a parametric filter board, and then an attenuator module.

This crossover uses the same basic circuit as the 5532 version I posted before. I added a couple tweaks, like muting relays and a provision for a gain control pot, although gain and frequency are still fixed, tuned for the 4345. I plugged it in to my system for this first time this weekend. It's a bit premature to describe how it sounds, I have to make some more tweaks and then I'll A/B test it against my 5532 version.

Pics:
http://farm3.staticflickr.com/2837/10396611964_6e9d341762_b.jpg

http://farm8.staticflickr.com/7396/10396644556_ddaebbc3c2_b.jpg

[bigyank]

Damn! Looking very good. Great workmanship too. Well done!

[Amnes]

I highly second the DAMN! Discrete analog crossover = pureness.

[Guido]

DAMN DAMN
A discrete active crossover... Wow, great and simply stunning work!

[tjnif]

will you be selling it?

[just4kinks]

will you be selling it?

Yes, eventually! But this is still just a prototype. I have bugs to work out, and as it is now the cost would be way too high.

Now I just need some time to work on it...

[danvprod]

Wow. These are exceptional. Excellent attention to detail, and I love that you chose to finish them natural to bring out that beautiful ply.

[Guido]

You could just sell the pcb's for the start.
Some of us would be able to work with it.

Oh, and a sketch of schematic for it.

That would be :cool:

[mario1o1]

What do you estimate the cost of the enclosure to be?

[just4kinks]

What do you estimate the cost of the enclosure to be?

I added it all up when I finished, I think it was a couple grand. That might include the crossovers. I'll have to check on my other computer, I'll let you know in a couple days.

[ngccglp]

Hi,

Excellent work on the crossovers. I am interested to purchase one if they are made available.

[Wagner]

When I see projects such as this I feel very insecure and as if I am just wasting my time

Beautiful work, superb

If I may ask, what do you do for a living, and did you grow up in a home which included another cabinet maker?

And where did you manage to source that much nice void free plywood, here in the Bay Area?

[just4kinks]

What do you estimate the cost of the enclosure to be?

Around $1500, not including the crossovers or components. Lots of little things add up.


Hi,

Excellent work on the crossovers. I am interested to purchase one if they are made available.

Thank you! Are you referring to the passive or the active? Either way, I have thought about selling them, but I haven't had time between work and other DIY projects.


When I see projects such as this I feel very insecure and as if I am just wasting my time

Beautiful work, superb

If I may ask, what do you do for a living, and did you grow up in a home which included another cabinet maker?

And where did you manage to source that much nice void free plywood, here in the Bay Area?

Thank you! It just requires patience, anybody is capable given the tools and free time. I learned woodworking from my father, we are both engineers. I write software for a living.

I searched high and low for furniture-grade baltic birch locally, the best I could find was BB/BB at Aura in San Jose, up to 1". I ended up special ordering B/BB from Forest Plywood in southern CA.

[chrapladm]

Amazing build and great pictures. I was looking at building a vintage cabinet and 4345 was the one I am most likely going to do. So this build is VERY helpful to me. :applaud::bouncy:

[hjames]

I was reading some older build threads here on the Heritage site, and ran across your excellent build thread.
So, this Friday will be 7 years on from your build - got any comments for us?
How have the speakers held up? Have you revisited those amazing crossovers, or ...??

[just4kinks]

I was reading some older build threads here on the Heritage site, and ran across your excellent build thread.
So, this Friday will be 7 years on from your build - got any comments for us?
How have the speakers held up? Have you revisited those amazing crossovers, or ...??

I'm glad you liked the thread.

The speakers are still amazing. At some point I upgraded the 2425s to TADs, they are so smooth. I'm powering them with Brystons now, I think they sound better but are less reliable than the Crowns.

About 5 years ago I added some low-pass bump filters to the crossover, modeled on the filter from the BX63/B460. It gives a nice boost at the low end. The crossover has been very reliable, maybe I will manufacture and sell them one day but I'm enjoying my day job right now.

I have kids now, and the house is normally too noisy to listen to anything, and everyone complains if I turn the volume up. So the system is mostly just used for TV, oh well. Every now and then I get a few minutes to enjoy it.

[DerekTheGreat]

...I have kids now, and the house is normally too noisy to listen to anything, and everyone complains if I turn the volume up. So the system is mostly just used for TV, oh well. Every now and then I get a few minutes to enjoy it.

I technically do now, too. Inherited from my fiancée. Turn it on and turn it up often. :D That's how you make music fans outta 'em. In just under two years' time I've got her daughters singing along to and requesting the likes of Queen, Aerosmith, The Beatles, Elvis and Commander Cody. The stereo is always on, just like it was when I was a kid.