I drive a Chevy Avalanche, and as those of you who own similar vehicles know, the articulation of the rear seats is important to retaining the full utility of your vehicle. My head unit is a Sony Mex xb100bt which puts out a real 40 wpc and I'm running Polk db651s in the doors. The setup sounded nice, but was lacking in the lows. I did a lot of research into adding subwoofers and found that almost all options required some sort of sacrifice in terms of retaining vehicle utility.
During my research, I ran across the Kicker Hideaway and similar units and my first thought was that there was no way that such a small unit could provide any sort of appreciable bass, but given the advancements in class d amplifier and speaker technology, I decided to give the form factor a try. I settled on the Kicker unit because, well...it's Kicker. My very first sub setup over 30 years ago was a Stillwater product, so I went with the Hideaway.
I installed it under the rear passenger seat and was immediately shocked, for lack of a better word, by what the little Hideaway was capable of. It was fully able to broaden the range of the music that I was listening to. Just based on my subjective comparison to my home system, I'd have to say that the Hideaway does get down into the mid 30hz range.
The single Hideaway did not turn my truck into a boom box, but the amount of bass that I was getting was appreciable. I listen to a broad range of music, ranging from classic rock and jazz to hip hop on occasion and did find that that single Hideaway wasn't quite enough for some types of music, so I added a second under the driver side rear seat. Now I'm getting some serious bass. Again, not boom box sort of bass, but a significant bass that is tight and fast that produces an experience that rivals that of my home system.
I did buy a 3rd Hideaway to install under the center of the rear seats, but it is still sitting in the box because I think I'm going to return it. With the 2 units alone, the bass is often times too much and I find myself running the sub control on my head unit in the negative numbers, with the gains on the Hideaways set at about the 11:00 position.
Most importantly, my back seats still fold all the way down allowing the full use of the midgate, so I've lost no utility at all.
As I said, I was really surprised by the performance that the little Hideaway is capable of. Advances in technology have indeed brought to market products that capably fill a niche that needed filling. The combination of the high efficiency (95db)/low impedance woofer and the 150 watt class d amp in the small sealed box makes for some nice bass.
The only downside to the Kicker version of this class of products is that in order to use the low level outputs on your head unit, you must use a high level to RCA adapter. It didn't think it was a big deal. The adapter was inexpensive and connecting it only took a couple of minutes. The trigger wire was also too short to get to my head unit, so I had to extend it.
I installed mine using an amp kit that came with 8 gauge power leads. I ran the power lead to my battery and to a small distribution block under my dash. It took me about 1.5 hours to get the first one up and running. The second was up and running in about half an hour.