Anyone try modelling clay to improve midbass?

**nobb** · 02-07-2008, 08:12 PM

My components sound great, but I am trying to squeeze a bit more midbass from them for a more rich, full sound.

On car audio forums, I see many people applying modeling clay in between and around the speaker and the door. The theory is that this isolates the speaker better and reduces the vibrations transmitted to the door. I am wondering if anyone tried this and noticed a dramatic (or atleast noticeable) improvement in midbass? Any special tips or techniques that I should be aware of? I live in a place where the weather can go from -40C to 30C, so I probably will be using rope caulk (as high density as I can find) instead of clay.

All my doors are deadened with 3 layers of Resisto and a thick layer of heavy foam in between the actual door and the interior trim piece. The door is sealed off such that the rear waves from the back of the speaker cant interfere with the front waves (in theory). It lowered alot of road noise, but to be honest the midbass improvement from this wasnt as dramatic as I had hoped. I am a bit skeptical on whether I will even notice a difference with a modelling clay mod, so Im wondering if anyone has any experience with this.

**boomintrac** · 02-07-2008, 11:35 PM

My guess would be to ask Red, as I know she has used it before but I thiink it was mostly for a sub enclosure. I know someone else was interested in this about a year ago try a search and see if anything pans out. I also believe the reason it was not persued was for the weight issues that would cause door problems down the road (I.E. sagging and misalignment)
Aron

**durwood** · 02-08-2008, 08:38 AM

Depends on if your door panel is still creating cancelations.

It definitely isolates, but at a cost of a loss of output ~3db where the energy is turned into heat.

If you need more midbass there are several options:

1) Enclosure if it's a low Q driver (QTS=0.2-0.4)
2) More power (depends if the driver can handle it)
3) More excursion (depends on if the driver has more to go or if it's already maxxed out)
4) Larger driver or more cone surface area (double up on drivers)

Not sure what frequency range you are using them in either.

Proper blending with the subwoofer will help you in the illusion of upfront bass. Time alignment and/or phase adjustment and proper crossover filtering can help with this.

**nobb** · 02-16-2008, 11:40 AM

Thanks for the suggestions. My components were pieced together by myself and the crossover was also self built from bare parts. The midbass driver I am using is the 5.25" Audax Aerogel (wish I went with the 6 inch instead):

http://www.partsexpress.com/pe/showd...number=296-155

It has a QTS = 0.41. The crossover I designed is a 12db/octave linkwitz-riley at 4200 hz. My 4 channel amp also separates the components from the sub at a fixed crossover at 80hz, 12db/octave. I am pretty satisfied with my components, I guess I was just hoping for a cheap and quick solution to up the midbass.

Originally Posted by durwood

It definitely isolates, but at a cost of a loss of output ~3db where the energy is turned into heat.

That number seems fairly significant. But whether it is a noticeable difference by the average listener, I dont know. My amp is capable of feeding each channel 75 wrms (but my components are 6ohms, not 4), and I dont listen to music at extreme levels so a little loss in output doesnt bother me.

**AWehmeyer** · 02-22-2008, 08:22 AM

If you've installed a bunch of damping material in the doors already, modeling clay isn't going to help.

Try this:

Disconnect the subwoofer and listen only to the front speakers. If the crossover frequency is adjustable, set it for the lowest frequency that provides crisp clean sound at the loudest level you'll listen. Don't pay much attention to the frequency markings on the amp. Then, add the subwoofer. If the crossover frequency is adjustable, set it to the same frequency as the front (now you do have to pay attention to the markings). Listen in the driver's seat and ask someone to reverse the phase of the subwoofer while you listen (or do it yourself). Choose the setting that provides the MOST midbass. Once that's done, you can be sure that the phase of the subwoofer relative to the front speakers is as good as you'll get without some additional processing.

Next, adjust the low pass frequency of the subwoofer and the gain (input sensitivity) control of the subwoofer channel until the sound is balanced.