Ordering: The Fi Audio website is easy to navigate. From the time I ordered the subs until the arrived at my house was around two weeks.

 

Unboxing impression: The motors and surround are large. These are no heavy weight contenders but for IB use they are beefy. The surround lets you know that these are high xmax drivers.

 

Install: I am using two IB315's powered by a Sundown Audio SAZ1500D v.3 @ 1 ohm and they are mounted IB in my 2008 Hyundai Elantra. The motors are facing the back seat. I use different settings for SQ and daily listening. For SQ I am using a 40hz/12db high pass and 50hz@18db low pass with a -13db cut on my H/U. This unusual cross over setting is the only way I was able to tame a heavily boosted low end. Dual 15" subwoofers with a high qts and small trunk in my vehicle is what dictated this. My JL Audio 8" midbass drivers mounted in the kicks help blend the subs into the front stage. For daily listening I use a 20hz/18db high pass with a 80hz/36db low pass with a -3db cut on my H/U. This gives me a heavily boosted low end. I often bump the sub bass level down on my H/U even for daily listening.

 

​Listening conclusion: I never had an install that produced 20-30hz frequencies to this extent. The overall SPL level isnt the loudest but the music reproduction under 30hz is nuts. I am very impressed with the design of these woofers. There are no mechanical noises and they soak up every watt of the 1500D. As with the unusual DSP settings I find the power consumption of the IB315's to be unusual for this class of driver. Most IB subs are not this power hungry. The design goal for the IB3 series is evident to be superior sub bass reproduction at a relatively high SPL level. Having a high QTS they may perform even better in a larger trunk or as a true infinite baffle setup in home or theater that may require less EQ and xover adjustment. For a SQ install two of the IB315 is certainly overkill. There is enough output to easily overcome the front stage.

 

​Conclusion: In my small sedan I do not see it possible to achieve this level of reproduction from 20-30hz while maintaining full use of the cargo area and spare tire. 30-80hz is impressive as well but the overall SPL level could be higher with typical ported enclosure sub stage. IMO 20-30hz with this much authority is very impressive and hard to achieve. From a biased SQ perspective this area of the sub stage requires heavy tuning. A battle of both worlds

 

Pics: (I am using custom carbon fiber dustcaps)

 

great review edub!!!

great review edub!!!

 

Thanks my man. You need a demo

Nice review Eric. I would have loved to do that to the wife's car, but she needs the room.

Nice review Eric. I would have loved to do that to the wife's car, but she needs the room.

 

There isn't much room lost, maybe 9-10" of depth. A pair of 12's would be shallower yet.

Those dustcaps are amazing! Very cool man.

wonderful review. nice install

Glad you like them

Wish i had monies.... Id do 12s of something ... Ib looks sexy !!!