Hi all,

I just recently switched my Q10 from being sealed in an ext. cab S10 to .9cuft port enclosure in an '88 BMW 325ix. I took a ton of time designing the box for the bimmer because I was looking for more output down low so I shot for 27hz using 4in PVC. I got it all built up and installed and I'm slightly disappointed with it so far. Things just don't seem loud enough. I figured going ported AND in a larger cab compared to the S10 I would get more output but I'm getting significantly less. I must add, the enclosure is sealed up to the rear firewall firing into the cabin of the car through the ski pass hole so I have zero trunk rattle. I don't know how this would affect things too much tho. Also, the Q is being powered by a SAE-1000D at 2ohms, so getting ~600rms.

It sounds hella good and smooth (except for a little peak at around 40hz) but it's just kinda lame, and i even get halfway decent response from kick drums. I just dont have the volume I'm looking for. I don't know if it has to do with too low of tuning, a shitty box build, cabin gain of the car, or what. Just looking for ideas of where to start trouble shooting. Any ideas where to start?

Again specs are:

1988 BMW 325ix

Standard D1 Q10, powered by Sundown sae-1000d

0.9cuft enclosure @27hz using 4in pvc

box is sealed against rear firewall firing into cab.

Thanks,

Mike B.

It's a combination of low tune and being in a larger car. Your idea of a larger cab helping bass is reversed, it actually hurts because now there is more air to pressurize. Not too sure on those cars, but I imagine they use some pretty good insulation on those seats and back deck, so you really only have the ski hole to allow the bass waves to pass, which isn't a lot of area, especially compared to a wide-open cab of a truck.

It's a combination of low tune and being in a larger car. Your idea of a larger cab helping bass is reversed, it actually hurts because now there is more air to pressurize. Not too sure on those cars, but I imagine they use some pretty good insulation on those seats and back deck, so you really only have the ski hole to allow the bass waves to pass, which isn't a lot of area, especially compared to a wide-open cab of a truck.

Ohhh I was kinda thinking it would be more like the effect of things getting louder when you roll the windows down but that makes sense too. So pretty much, I could try to shorten the port a bit, but mostly I'll just have to deal with it?

tuning lower kicks you in the ass in the SPL and excursion department, thats why I went with 4 18's in a wall... so I can tune ungodly low and still be reasonably loud. slap together another box just like it but tuned higher to compare if possible.

You've got a single 10 in a BMW..and it seems like you are wanting it to sound like a pair of ported 12's.

You can't expect it to be loud...those cars absorb a TON of sound.

Don't tune it much higher then 30Hz or so..you're going to run into mechanical issues if you do