Modeling Clay to Dampen Speakers

Anyone here ever use modeling clay to dampen speakers? Drivers and inside cabinets.

 

What I use is a mixture of latex roofing cement and sand, I also use that on turntable platters. But it has to dry for 24 hours before you can handle the piece.

 

Moretite rope caulk is good for this purpose: it never dries out or hardens and can be used straight away.

http://www.energyfederation.org/consumer/default.php/cPath/21_28_1223

 

I use Dynamat. It sticks well enough so that you can use it on the stamped basket ribs, too.

For inside the cabinet I use Black Hole 5.

John K.

 

I have also used Dynamat on the ribs of cone drivers, and also on the outside of horns. It was a lot of work and I don't think my system was up to revealing the differences anyway.

Btw, Frank Van Alstine wrote about this in his Audio Basics papers back in the 1982.
http://www.avahifi.com/root/audio_basics/ab_pdf/ab1982.pdf

 

Pray tell, why would you want to dampen your driver? Just curious......

HG

 

Does'nt this deaden the sound?

 

The idea behind damping the horn basket or the cabinet itself with mortite or dynamat is to control or eliminate unwanted resonances.

When you place damping material on a horn or basket of a speaker you are attempting to get rid of unwanted ringing. In the case of a horn, it can actually ring like a bell, a driver does also, just less so.

Damping a cabinet adds mass and helps with imaging. The best way to achieve this is a piece of heavy granite or concrete on top of the cabinet and a sand box underneath the cabinet. The increased mass lowers the resonance frequency and the sand box absorbs vibrations.

I'm just now getting into this for my fairly large Edgarhorn Titan system. There are people that can explain the physics much better than I.

 

Unwanted ringing overtones, etc.....

I was visiting with Don Allen (Phoenix Tube Amp Desinger/Guru) yesteday and he recommended it for my Klipsch Heresey Speakers. I'm not actually familiar with this alteration, but I might try it.

 

Tone, this is a good cheap tweak for your Heresey's.

Get the moretite, it's neat stuff because you can always easily remove it later if desired or if you sell.

 

Thanks Chad. Will do...... This is why I brought it up at the forum. You can always count on an opinion here.

 

Yes, I agree that damping the horn, basket, or cabinet of a speaker may be a good thing, but, I'm not so sure that applying a damping material to the driver magnet is a good idea. While it may get rid of some unwanted vibrations, It may also change the Q and the resonant frequency of the driver.

HG

 

I was referring to placing moretite on the basket of the driver, I hadn't considered the magnet itself, not sure about that one actually, I haven't tried putting caulk on the magnet.

Some guys also put Dammer or C37 varnish on the paper cone.

Don't even ask about the light bulb trick for full range drivers!

 

Sorry, but that's not modeling clay, it's ductseal. It works great for damping steel speaker baskets, but I wouldn't use it for damping boxes. Ductseal is available in the electrical department of hardware and building stores.
That pic is a Fostex FE126E driver from the planet_10 hifi site.

Jeff

 

Has anyone ever tried putting black insulation tape round the outer edges of the speaker cones to cover the small gap between them and the speaker carcass.

If you haven't try it you may be in for a shock. Some speakers will become more defined in their sound and others will sound dead.

 

one of the best things I did for my speakers was to put them on spikes. Everything got better, especially the bass.

 

Blue Tack is a useful tool to reduce resonance

But a well designed driver should not need damping

And some cab designs (LS3/5a and BC1) rely on thin resonant walls

Its a conundrum....

Roger imho

 

That's what I always assumed...if the manufacturers did their research, there shouldn't be any reason for using rope caulk on horns and driver baskets to eliminate resonance. Then again, I was never one that got into the DIY mod craze...not that there's anything wrong with it. I just never experienced any real reason to do so to any of my components, loudspeakers or otherwise.

But that's just me...

 

The reason people get into DIY is that you can better the sound by modding store-bought gear and outperform most of it by building your own.

With speaker design for instance there are many corners cut: crossovers are usually cheap (caps, resistors and transformers), wire is not the best and cheaper materials are used as much as possible to keep costs down. Bracing is usually minimal on cabinets as well. It is very difficult for the big manufacturers to turn a profit otherwise, so they have to save money by using cheaper stuff and cutting the aforementioned corners. Most dealers have a two-foot rule which eliminates a lot of bigger designs that would function better than the designs on the dealer's showroom floors. They are wary of such designs due to WAF and other aesthetic factors.

A lot of the tweaks that we have mentioned in this very thread are recommended by many of the designers and manufacturers of the popular brands of speakers used by audiophiles. There are many speaker company owned forums that offer tech advice and support for modders.

All of that being said, you don't always damp drivers. In certain cases it serves well, in others it is a detriment.

 

I used to design speakers for a living and fiddled with a lot of this stuff.

I'd think modeling clay would dry out. Mortite is indeed nice stuff. Just be sure that if the driver frame has a very slick finish that the Mortite won't fall off.

To say that if the driver was made properly you wouldn't need to do this is incorrect. Everything is designed to a price and can often be improved with some additional work-think underhood strut tower braces for cars and so on.

I'd particularly dampen any horns you have. The metal or thin plastic walls not only resonate, but may actually transmit audio pressure from inside the enclosure.

But a much bigger difference can be made by stuffing the cabinets. I had that make a stunningly humongous difference with some old speakers I refurbished. You could start a whole other thread about this, but fiberglass stuffed densely is the old standby material for this purpose. Note: if your system is ported, stuffing will lower the effective port frequency, so you might want to only line the walls, and don't block the inside of the port.

 

I tried adding some additional insulation to a McIntosh speaker cabinet and although the sound tightened up a bit, it totally eliminated the lower bass frequencies.