Dr Durden

There you go! The king of "cardio" right there. Lifting weights is even better.

Structure governs form. Form follows function. Therefore your form is dependent on structure. Strength depends on position. Change position, change strength. Point: there is no such thing as "correct form" outside the individual's structural integrity and position. And this is why you see the Russian guy being able to lift a chitton of weight off the floor essentially with his hydrolic amplifier system of his back. His legs are TINY! His form is not correct for anyone else except him. He's merely getting away with it, that's all. As they say "Do not try at home."

You're promoting me to some type of Mod status for knowing what you were about to say before you said what you said - thus, in effect, reading your mind - I'm assuming??

The d2904/6000 has an Fs of 750 hz, IIRC. Nice, robust tweeter.

Structural damping has many forms and doing something like cross bracing a closed-termination device [think of the door panel as a snare drum] may be all you need to do what ///M5 just mentioned. You could use an epoxy I suppose. I used a marine epoxy in my baffle construction and it's withstood a beating from some pretty potent 8" midbass and subs mounted to it. You could also screw it to the door itself where ever you have room and a good, long stretch of open door....preferrably to connect one side to the other. In my mind, the vibration will take the path of least resistance through the brace rather than through the center where vibration is probably the highest? Not too sure. No pic, sorry. If you search Ge0's install log on DIYMA, he did something just like this with cross-bracing and mass loaded clay.

Yea, totally! Pretty much what I was thinking but couldn't spit out in my reply. So smart, you are. My disgust with "mass loading" comes from several members on lots of forums who seem to be hopelessly addicted to the following notion: Mat is for mass loading, no more, no less. If you really think about it, it makes no sense because the most popular deadening mats everyone knows and loves are not HEAVY!

Yes. This will raise the RF of the door, most likely. Adding mass will probably drop it back down. IMHO, once you cannot locate the driver, it's dead as dead.

A constrained layer damping system (butylene rubber composite + sufficient aluminum foil) is designed to convert vibration to heat. Heavier "deadener" isn't better; more effect damping (CLD or otherwise) IS. A perfect example is something like mineral-loaded vinyl damping sheets (Parts Express, Cascade VB-2) which has no constraining layer, is lighter, but will out damp a CLD mat. A thick layer of Skippy Extra Chunky peanut butter has more mass than a single layer of Dynamat Extreme, but it's not going to work. Damping is dependent on the visco (water-like) elastic (ability to return to form) nature of the damping material, not on weight. Weight is just one element. Reflection is a different physical phenomenon. Absorption is a different physical phenomenon. Point is, different materials do different things - although they do overlap. IME the best way to properly attenuate [do we ever get rid of it?] the back wave is to make a proper baffle. A crazy Kiwi dude that's on a few car audio forums once told me that a baffle is the device that creates a loudspeaker, not necessarily a dead door. Anyway, enough rambling. HTH.

Korn

If you want the best midbass response possible, and it's not an extremely high-end luxury vehicle with a lot of deadening already installed, you're going to have to, I'm afraid. But it's well worth it While I generally agree, we have to use the term "deadening" pretty selectively. Most associate "deadening" with the app of CLD mat (ie Dynamat). But a simple cross brace on the driver mounting surface might do the trick depending on which driver is in door and the freqs it's playing. LOTS of forum-goers have been misled with the notion that CLD is mass loading, as in the goal with CLD mat is to add mass. Sure, you're adding mass but this is not really what you're after. If you want to add mass, then cross brace and pack around it with non-hardening modeling clay. Better yet, mass load the clay with chunks of rubber, lead, or steel....or something that's dense and heavy. My $.02 after using CLD mat and every other "deadening" product in my doors and all over my car.

deadener everywhere even on the glass. more heavier, more better results so mass load those rattles. ///M5 is right, the chit gets old. How many times has this question been answered?

Nice! Finally some good evidence for the application of a barrier. You mentioned a dip between 100-300 hz on the RTA. About how much reduction in dB did you see there? Overall?

Completely different acoustic phenomenon, actually. You're talking about structural damping, which has many forums. Generically speaking, damping is using an elastic modulus to convert mechanical movement (vibration) into innocuous heat. When we're talking about absorption in a vehicle in relation to damping, we're talking about taking care of any airborne noise left over after structural damping is attempted. Also, damping doesn't make a surface impenetrable to noise as it's not designed to. Noise you don't want in your car will refract right around a fully damped panel, for example. Dampers make for poor absorbers and absorbers make for poor dampers.

That dude has done more acid than I could do in my entire lifetime. I'm kidding and yes, I am familiar with his stance. I'm still on the fence, though. Don't see how the mass accounts for anything substantial, personally. I'm willing to bet you will not see a major difference in results by gluing two pads two each other vs using just one. Hell, slip a sheet of lead in there to make yourself a Deflex pad sammich and I'd expect to see the same result on paper as using just one. Great experiment though right there.

Good point. Please add to the discussion, man. You know way more about this than me!!!

Sound Absorption There many definitions that exist for sound absorption. Almost all of them will mention the conversion of sound energy to heat energy via some sort of medium. The best working definition, to me anyway, is non-reflected incident sound. In this case, for example, an open window is the perfect absorber as it reflects 0% back to your ears. The best absorber, therefore, is one that attenuates a sound wave by 100%. The ability of an absorber to function as such depends on its porosity, size, shape, etc.

Seems they work on the ITD (initial time delay) which helps "clean" up the sound due to the acoustical phenomenon of diffusion. So even if the troughs are not at least 1/4 of the lowest frequency wavelength, it seems they can cause a shifting great enough to cause an overall audible response. CAE has some data on the effects of their product, and to me that's what looks like is going on. Plus we all know what happens when sound is shifted and shaped due to the negative effects of early reflections and odd order harmonics all bouncing around in a small space (ie a car). Maybe these pads turn that negative into inaudible? I don't know.

If you think the "anger" expressed by a few of us here has to do with....

If you're going to be running the L8's, then 400 watts each should satisfy.

http://web.archive.org/web/20041027051204/...rces/fiberfill/

Yes.

Download NCH Tone Generator.

0 dB when level matching channels on the amps. Sound Forge or other software scans of familar music when tuning and setting gains. I typically use tracks that have an RMS of about -13 dB when setting gains. Madonna's Immaculate Collection comes to mind as a disk I use all the time.

That was my tip off, first of all. Second, it looks exactly like how I formated it on my website. Third, it's nowhere to be found on SS's website AFAIK. Listen, you got what you needed so it's cool. In reality, we're both just going off the testing done on the product and copying it anyway.