22 replies to this topic

[BMWTurbo]

shizzle, on 15 June 2010 - 01:24 PM, said:

Heya,

Nope, none at all. By vent, do you mean port, or vent into a cavity behind it, to increase the volume?

I was thinking about an AP enclosure, but not sure I can find an airtight cavity behind the kickpanel.
There is however a nice space that goes into the front guards behind the kicpanel, that I could vent to, but that would make it almost IB in effect (unless I put an AP between the kick and the guard.

Vent as in let the rear of the cone see atmosphere/outside (protected of course). It's very hard to actually seal a kick panel, I'm not sure on your vehicles make up, but in the BMW and other vehicles the kcik panel opens out into the sill cavity which can extend teh full length or the interior, extra volume, great, but also the posbility of rattles and transmission into the carpet etc via service holes.

AP venting to outside would be good in theory also, providing you don't need the extra level that you will loose by AP'ing the driver. I recently saw a thread rear maknig the kick panel into large sealed enclosures on a E34 BMW on DIYMA that was awesoem work, a fair bit of work yes, but totally watertight and a nice sealed enclosure created.

If you are keen to experiment then make the panels up and worry about the 'rear' of them later as you can experiment. I use open cell foam jammed into my kick panels to try and reduce the resonance etc be resticting the airflow, a 'rough' AP style if you like.

[shizzle]

Heya,

Well, currently, I have 12L fibreglass pods made up, that form my kicks. They are sealed, and bolt into the metal where the kicks are.
My idea was to vent these to the panel behind the pods, which goes into the front fender area (open to atmosphere basically). This would in essence give them an 'IB" kind of enclosure, would would be good for low end extension (i presume)

Sound feasible?

[BMWTurbo]

If you already have 12 L sealed enclosures that are in the kick panels, how much extra work is it to ensure an airtight seal against the kick panel and the enclosure so you can ensure that no leakage occurs when you vent them?

I may have missed it in the original post, but what is the problem with the 12L enclosures currently? Have you modelled or tested that actual response currently? Using a smaller enclosure for midbass specific duties might not be as much of a concern/impact to overall response when you take into account cabin gain etc.

[shizzle]

yup, allready posted a graph on 12l vs 40l on the 1st page. THe recommended enclosure is 24L, but I will be crossing them higher, so it should not really make a difference.

I am getting new speakers (6.5" currently, getting 8"'s) hence why I thought I may need more volume.

[BMWTurbo]

Ahh yes I see now... I should have looked back

I wouldn't change a thing to be honest, if you have the drivers wide and deep towards the firewall with the 12L they should sound not much different to the larger enclosure and should be fairly flat with cabin gain taken into account. *edit* shouldn't have said flat as such, I meant better extension.

Edited by BMWTurbo, 16 June 2010 - 01:23 PM.

[Pulse-R]

once you put in the car's cabin gain, that peak will get bigger for 12 litre.

[BMWTurbo]

Pulse-R, on 15 June 2010 - 11:00 PM, said:

once you put in the car's cabin gain, that peak will get bigger for 12 litre.

Agreed, the peak will get larger, I was more referring to the extension which was what I thought Shizzle was focussing on...

[br85]

Again, what's a couple of db to tune out compared to those freakin' window mechs buzzing and carrying on?