FI IB315 Doable?(Box dimensions known)

[wckddudeman 0]

I was trying to spec out a large enclosure car audio build. I am working in the range of greater than 13ft^3, but less than 14ft^3(depending on speaker displacement and thickness of mounting.

I am unable to respec the box dimensions. I was wondering if this box would be capable of working with two IB315's or if this is too little of a volume for proper operation. I am looking at a QTC of between .735 and .75 depending on just how much space I lose to sub, sound proofing, and wood displacement(not sure if this calculation would stay the same with two subs sharing the same volume?).

My desire for an IB setup is low power requirement needs, and using the box as built.

Thanks for any info.

[Impious 1,476]

You would be pretty close to a volume equivalent to the VAS of the drivers, which without running the #'s to determine the resulting Qtc I can tell you that you would be pretty close to the lowest acceptable volume required to reasonably be considered "infinite baffle". That said, there's nothing inherently wrong with using them in a slightly smaller enclosure, you'll just experience a little raise on Qtc and a resulting shift in the frequency response.

Any particular reason you are stuck on using such a large enclosure? Not that I have anything to say against IB, I run it myself. But most people running infinite baffle in their vehicles use their trunk/etc as an enclosure & don't actually have a 13cuft enclosure in their vehicle. If you don't have the space or layout to run car audio's version of infinite baffle, I think you might be better off saving some space & utilizing a ported enclosure.

[wckddudeman 0]

I am using a cherrywood casket as the enclosure, the car is a 72 miller Meteor Hearse/Ambulance. So trying to make the install look nice without requiring boxes mounted inside the casket, that and since I no longer have access to a large space for a work area was trying to limit the amount of woodwork required. Also appreciated that alot of IB installs said that the sound quality was fantastic.

The exact dimensions would be 78"x24"x12.25"(using a 3/4" mdf sheet for the top, So a total of 375.788152L, slightly over the Vas for two of them) I would lose a small bit more space from adding a mounting ledge and a couple horizontal braces to help support the mdf sheet.

I guess it wouldnt be too bad to find something to support a 2x2x2 ported box but power requirements were my other concern, liked that I could run 2 15" off of a single 900watt amp.

If you have any suggestions for alternate speakers I would like to hear them. I prefer clean crisp lows to boomy, and listen to a wide variety of music.

[duanebrow 6]

Sealed boxes are very forgiving. With that box size you aren't going to be able to tell the difference in changing the volume a foot or so.

[wckddudeman 0]

Would 2 IB312's give me a good amount of bass in such a large vehicle? That would put the Qtc at 0.69 according ti WinISD.

The 2 IB315s in the same box put them at a QTC of 0.86, not as flat but has a higher db value overall, other change is the group delay changes from 15-22hz

to 22-30Hz with the 15's.

I have an amp already(was going to install a Pioneer TS-W5000SPL which I have lying around, so had bought for that, but then came up with this idea).

Sorry to be so persistent, just want to make sure of everything before I spend >400$ on subwoofers.

[Impious 1,476]

What exactly are your goals for the subbass?

With that much volume you could do a ton of different things. And I wouldn't limit your options to the IB3.