My next project

[NickH]

Busy 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

[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!! (hopefully)... By the way, what HF driver/horn du you have? Sorry for all the questions

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.


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!! (hopefully)... By the way, what HF driver/horn du you have? Sorry for all the questions

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-B...roduct_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.



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



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

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



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.