opinions on an IB setup?

[truckramrod 10+ year member]

My girlfriend has a 95 nissan 200sx coupe with 2 Infinity Kappa Perfect 12s and I would like to turn it into an IB setup (her current enclosure is about 3.2 cubes port tuned to 38hz).

Anyways the main issue I see is the trunk volume is about 10.5 cubic ft and each subs Vas is 3.5 cubic ft, so ideal trunk volume would be 70 ft, but I only have 10.5 cubes.

Although I read a few posts that said a minimum of 4X Vas is acceptable and another post said:

QUOTE: Its not 10x Vas, its when the Q of the alignment equals the Qts of the woofer. Some woofers don't 10x Vas airspace behind them to achieve this (for all practical purposes).

Would this be worth a try? The current box sounds ok although peaky, it takes up a lot of trunk space and the actual wood got wet and is swelled/starting to split.

Click to read more...

 

[Immacomputer 10+ year member]

Whoever said that true IB is when the Q of the system is equal to the Qts of the driver was correct.

Are these just kappa perfects or are they the VQ versions? If they're the VQ, I think they would sound great in a trunk baffle situation (you're never going to really have IB in a car really) and if they're just the Perfects, they should still sound pretty nice in an overdamped alignment.

 

[truckramrod 10+ year member]

Well, thanks for your opinion, I hope to start on this in the next week or two!

They are the regular svc 4 ohm kappa perfect woofers, getting 250 watts rms each.

I'm excited!

 

[truckramrod 10+ year member]

Would these even be worth a try to put in an IB setup?

http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16056

The high Fs makes me think they wouldn't work well.

 

[truckramrod 10+ year member]

Also I understand I may lose output going from ported to IB, but with the 2 woofers and the power I have, what do you guesstimate should be a realistic decibel level? Is 135 db out of reach?

 

[Immacomputer 10+ year member]

Would these even be worth a try to put in an IB setup?
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16056

The high Fs makes me think they wouldn't work well.

Eh, I would steer clear of those for a trunk baffle setup. And there is no way to tell you what your output will be. Your low frequency extension should be greater than the ported enclosures but there is no way to tell you if you're going to be over 135dB or not.

If you're looking for other possible drivers to consider for a trunk baffle setup, you should explore these options:

Exodus Audio DPL-10: I own one of these drivers and use it in my room. It is a very clean sounding driver and it's very laid back and natural. A pair of them would work very well in a situation like yours.

http://www.diycable.com/main/product_info.php?cPath=24_93&products_id=674

Exodus Audio DPL-15: If you're looking for just a single driver, this would be a good option:

http://www.diycable.com/main/product_info.php?cPath=24_93&products_id=684

Acoustic Elegance IB15: Don't be intimidated by the large Vas number.

http://www.aespeakers.com/drivers.php?driver_id=8

You can email John at AE and ask him about building an IB 15 specifically for a trunk baffle setup and he will take care of you. He is a great guy to do business with and he really knows his way around a loudspeaker.

 

[truckramrod 10+ year member]

Eh, I would steer clear of those for a trunk baffle setup. And there is no way to tell you what your output will be. Your low frequency extension should be greater than the ported enclosures but there is no way to tell you if you're going to be over 135dB or not.
If you're looking for other possible drivers to consider for a trunk baffle setup, you should explore these options:

Thanks for the suggestions on those woofers.

Well I picked up a set of the Soundstreams last year and I was just wondering if it was worth a try.

I am going to use her kappa Perfect 12s in the IB setup, the trunk to back seat cutout is just perfectly sized for it.

I will probably do a double baffle with the woofers inset (not necessarily flush just using the front baffle for some clearance along with the increased strength).

In your opinion, would it be worth it to dismantle the rear seats to remove the hard fiberboard in the backs of the cushions to allow the bass to come through better?

I guess I need to take it apart to see if i can remove that while keeping the seat from crumpling.

Thanks for taking the time to answer my questions!