Audio Systems: Car Audio, channel amp, vented box

Question
Heya mate,

I've recently had my car stereo installed...

Pioneer DEH 5850 Head unit
TS-A6991S 6x9s
GM-6200f four channel amp
Gm-7200M mono block amp
TS-C1625 splits
2x TS-W306C subs

A couple of questions....

a) is it possible for you to tell me the optimum settings for a hatchback...
b) is porting any good?
c) both the subs are facing each other does this create noticable distortion or should they be turned away from each other?...this is the only way they will fit...

Any help on the matter will be much appreciated
...cheers


Answer
A)  Settings for the system (level and crossover stuff) are best done subjectively.  After much listening and playing your favorite "test" music set them for the best sound to your ears; after all, you are the one to please.

B) Yes, porting of the subs is good; it really depends on the speaker parameters and how big the box is going to be.  Under the most ideal conditions this pioneer works best in a sealed box if space is limited, but a vented/ported box is better if you can get into a bigger box size; the vented box can deliver a good 3db more energy out and a little bit lower fc or f3.

http://www.ryda.com.au/ProductDetails.asp?ProductCode=306CBOX&Show=TechSpecs

The above is a box you can buy that is designed around the subs you have.  There are many others.

C) Doesn't matter if they are properly boxed and properly wired in phase and driven by identical amps.  They build sound pressure and at low frequencies such as subs handle, the sound is non-directional; so it really doesn't matter how or where the subs are mounted in a vehicle so long as they are acoustically loaded correctly.

In an automotive vehicle the space is small compared with home type rooms, so the balancing of the subs to the small space is a key factor. It is often done by trial and error; the nice thing about a vented box is you can change the vent easily once in the vehicle for tuning; whereas the sealed box is pretty fixed and all you can do it move it around a little.

There are many primers and design guidelines on the net; just do a google search for sub designs for auto and you will get some good stuff.

Cleggsan