Problem with Subwoofer

This is for good preparation for the Mk2.

I've got a new car - a limousine. I bought a 5 channel amplifier (4 speakers in the front, 2 speakers in the back and one sub)
Everything is ready connected and I think it'll do fine with the Mk2 (currently there's only a factory tape deck mounted). I know the quality is not very good - especially the bass is not as good as it should and hopefully it'll be better with the Mk2.

But nonetheless I've got a problem with my Subwoofer.
I had the same sub in my old car which was a hatchback. And it's sound was great. Enough power.
But now in the limousine the sub is in the back of the car, separated from the passenger's space.
If the volume is a little louder you can hear the bass but not as loud as it has been in the old car. If you open the pack door (for the luggage, where the sub is you hear it very loud. So the back is just pretty good isolated agains noise (and sound also).
What could I do to make the bass' sound better without changing the car too much (to not loose the warranty)?

(I've already posted this kind of question in the General BBS. So Tony please forgive me for asking again. Noone had an answer which was really satifying till now.)



TeeMcBee

What could I do to make the bass' sound better without changing the car too much (to not lose the warranty)?
get a bigger sub


as you expand the space you need more power to fill it. would your home stereo be sufficient at the super bowl? they use massive power and broadcast systems because of the amount of air they have to move.
Your hatchback was considerably less volume than the limo (lucky for some!!) and the smaller (?) sub was enough. there is probably some equation like square the volume and cube the power or something. Any pro-audio PA guys out there?

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Murray

Sorry for not responding before now - did get your mail, but I've been seriously busy.

A few things to try:-

First off, trying wiring the sub 180 degrees out of phase with the rest of the system, ie. reverse it's polarity.
If that doesn't work, trying firing the sub towards the back of the boot (assuming it's not already). This is a good idea in general anyway, as you increase the path length to the listener, resulting in lower wave propogation. f that doesn't work, try positioning the sub so it's about 30-60cm from, and firing directly at the corner of the boot compartment.

If none of the above has any major effect, then you're going to have to somehow increase the airflow between the boot and the passenger compartment. If there's a 'ski hatch' option on your model, but not one fitted, then quite often there'll be a metal panel that you can remove in the centre of the back seat (behind the seat squab) without effecting structural strength. Failing that, about the only other option is to somehow cut ports through the rear shelf, then cover them with acoustically transparent cloth so they're not visible.

With the latter physical alterations to the vehicle, there is a slight danger you'll increase the amount of road noise entering the passenger compartment, but it shouldn't be too significant, and could probably overcome by a layer of Dynamat or similar applied to the boot floor.

Dominic

Cambridge Car Audio
http://www.cambscaraudio.co.uk

Now there's a damn good set of suggestions. You guys know your stuff there.

May I also add that some subwoofer amplifiers come with a polarity reversal switch so you don't necessarily have to touch the wiring.

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Tony Fabris