From digest.v7.n1364 Mon Mar 23 01:31:04 1998
From: Dean <schreier_at_airmail.net>
Date: Sun, 22 Mar 1998 22:33:04 -0600
Subject: Re: Subwoofers for E36 - My opinions (longish)

Hi all you bass hungry E36's,

I'm not trying to "flame" anybody, but here's what my experience tells me.

I looked at the JL stealthbox page (I haven't heard it yet), but I can tell you what it probably sounds like based on the description of what it is (infinite baffle). It probably sounds "loose" and "muddy" like MOST infinite baffle setups.

Also the JL flexports, I'm not sure how these attach, but realize that any time you add ANYTHING to a speaker port you are changing the tuning of the original port (for better or worse, usually worse).

About removing plastic housing on the factory mids to increase the bass entering the car: Technically, this is a bad idea because it causes the midrange driver to act like a passive radiator. This will effect both the sound of bass and the midrange. Realistically, I may sound fine.

I was in the car audio business for 9 years (installer and sales). I have tried a few things in my E36, all using a very large Fosgate amp:

1. sealed box/sealed trunk (rear mids still inplace) - bass was slow (damped), but tight and low. The car resonated really bad, not the speakers or the box.
2. same sealed box, but removed the rear mids to vent into the car - bass louder, but still slow. Resonance worse. And to top things off the car could no longer be driven with the sunroof open, with out opening a side window (wind buffeting???).
3. Aperiodic membrane - best I've ever heard without compromising the structure of the car and I don't really lose any trunk space. There are ONLY two ways to get this type of setup. First, find a dealer who knows what it is and have it custom built (this can be expensive). Second, buy the Dynamat version and try to make it work without cutting. This setup looks like an infinite baffle to the casual observer, but sounds like a good sealed box (tight, accurate). It's not excessive, it's just right (true to the recording). The resonance of the car is gone on my setup, partially due to the quantity of MDF that now lines the underside of the factory rear deck, a tiny bit due to the dynamat on the top side of rear deck. (see it_at_http://www.geocities.com/motorcity/4793/)

Bass and sound quality are all a matter of personal preference. I (in true audiophile fashion) was trying to achieve a car system that reproduces (as closely as possible, without cutting my car to bits) what the recording engineer heard. My system is VERY true to the recording...so a crappy recording will sound sound like crap, and great recording will be wonderful and emotionally involving. Loud and even "uncolored" sound is pretty easy in a car...correct soundstage and image are much harder. Everybody talks about rear fill, you DON'T need rear fill if the fronts create the correct image and soundstage. Rear fill is just there to "fool" you into thinking that a soundstage exists. (the only time you really need rear fill is if you are running a true 4+ channel program, DSP, Dolby Prologic surround, ETC). For 2 channel it's waste, and if you toss the rear mids, your rear passengers will stop complaining that the stereo is too loud and they can't hear the conversation in the front of the car...

So it really all depends on what you trying to achieve and how much money you are willing to spend. A "reference" sound system will never come cheap, but a decent one can...just don't expect more then your wallet can handle.

Dean Schreier
Dallas, Tx
'96 M3 (stereo, tint, OMP pedals, short shifty thing) http://www.geocities.com/motorcity/4793/