Okily dokily, in the middle of building my kicks. Was thinking of ways to deaden them. Got to thinking about the idea behind using mat's and such. Correct me if I'm wrong here, but isn't the idea behind them to add enough mass so that the offending resonations are either stopped. or moved out of the audible range. With this in mind, I got to thinking of best ways to add mass and came up with an idea. I have a rather large stash of lead shot ( used to reload shells for my dad ) . Any thoughts on coating the inside of the kicks with an epoxy lead shot mix ? Seems like it would work. Any input would greatly be appreciated.

Commonly used approach is to just use non-hardening modeling clay.....but I suppose if the lead is heavy enough and would stick well with the epoxy to the kickpanels...I suppose that should work. I don't know, off hand, how much heavier lead shot is per cubic inch than something like modeling clay, or how much more/less expensive per ounce/pound.

Interesting thread about mass loading vs bracing: http://forum.carstereos.org/advanced-audio...ghlight=bracing

Read that a while back. Price of the shot doesn't matter too me. I have a 50 lb bag of number 8 shot in the garage from my days of loading shot gun shells. Clay was my original choice, until I got to thinking about the lead. I'm gonna play around a little when I get home and test some things

A lot of those materials such as dynamat or deflex pads aren't just heavy though.... they are very efficient at changing the pressure waves comming in perpendicular to the material into waves that move parallel to it's surface and spread out once "absorbed".

Solid lead kickpanels...would make people think twice about putting a foot into your speakers.

Ooh, are these footres...HOLY FUCK, MY TOE...

You guys will probly think I am crazy...but wouldnt you want the LEAST amount of metal around/in your enclosure? I would think a ton of lead shot would mess with the speakers motor...Something I have always wondered.

Lead has diamagentic properties, which will result in a very small repulsion from any magnetic field (magnetic susceptibility is negative).

Now, how much effect that it would have on the motor, I do not know, but even so, having something toxic in my enclosure is something I don't strive for

Diamagnetic materials make the best conductors though

http://www.ian.org/Magnetics/Diamagnetic.html

Mass is more of an issue on really thin body panels than in your glass enclosures, if you are real concerned just make 'em thicker and they will be so stiff that there resonant freq. is so high and damped that you won't excite it. Since stiffness isn't your problem and reflections are I would propose a more fabric solution. I am a really, really big fan of 3M's thinsulate acoustic insulation. It is a lot like the fiber-wad crap that OEM's use, but it actually works. Oh lead won't have any ill effects on the magnetics of your speaks. Pretty much heaviest mass per unit volume you can get, use it!

Could always use bismuth shot, which is really close to lead's mass but non-toxic...not really sure that the toxicity matters anyway if it's encased in resin

toxicity ?? I'm building kicks not a cereal bowl

toxicity ?? I'm building kicks not a cereal bowl

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Even handling lead will be harmful, not quite to the level of ingestion, but effects are still there.

A lot of those materials such as dynamat or deflex pads aren't just heavy though.... they are very efficient at changing the pressure waves comming in perpendicular to the material into waves that move parallel to it's surface and spread out once "absorbed".

Two different things.

Mat deadeners/clay/lead shot in epoxy ( ) = mass loading. They don't do crap for the soundwaves, but they add mass to the panel and reduce the vibrations and change the resonant frequency of the panel.

Absorption/reflection/diffraction of sound waves = barrier loading. This is the foam and deflex pad products. They don't do crap for resonances.

You can (and should) use both....line the enclosure with something heavy to reduce vibrations and resonances, then use foam/deflex pads to absorb, reflect and/or diffract the soundwaves.

Exactly

Thats why people put deadner on the door panel and a deflex pad or egg crate foam behind the woofer.

crack open your average high end large HT cabinet and you will find led panels in them quite often.

Lead is only dangerous when injested in high levels or over long periods of time. Dont eat your paint chips in old houses and you will be ok. It CAN hurt if yo uexpose your skin to it for ever, so insentive for geusts to not touch your walls and get their nasty figner grease all over the place.

Anyway, im jsut saying lead isnt as poisonious as some may think. Im not saying to start taking your reccomended daily value of lead with your vitamins, but dont avoid it like the pleauge when its an awsome mass adder.

With that being said put some cat hair fiberglass in with it and you wont have any problems. some guys on DIYaudio.com epoxied pebble's into their HT enclosures after they found out hot glue let go (lol, lots of rattles) and though i havent been over there in ages because everybody is way over my head (i ask a reccomended tuning and they start going intoremoving nodes from my doors, WTF?) but ~1month after they changed their plan of action i didnt read any complaints. Go fur' it mang.