I bought my TSX after years of driving a SUV so space is a premium. Personally I think the OEM system is pretty good (as OEM goes) and the car is leased so I didn't want to overhaul the whole system.

My first upgrade was replacing the 6x9s with a pair of Alpine Type S. Overall I was disappointed. On the OEM amp they played noticeably quieter. Then I added a Sony amp which I had in last car. Boy, talk about an improvement. The Alpines play very low when you give them a bit more power.

However I had a new problem -- rattling rear deck, especially the center seat belt housing. Its terribly annoying on some tracks. I found an odd fix, but actually effective. I reversed the low pass to a high pass and set it at 50hz. SInce there already is a low pass crossover on the OEM speaker leads this basically acts like a subsonic filter. This eliminated the rattles, but am I gaining much over stock now? After a couple weeks of this set up, I forget how stock sounds. I might put the OEMs back in and see what the improvement is with the Alpines and HPF on.

Next, I had a left over 8" Pionneer Premier sub. I was shocked how much this sub sounded like a 10" when I bought it and had a high end shop believing it WAS a 10" before I told them otherwise. I was curious to see what it would sound like with this set up. So over the weekend I built a very small wedge enclosure (it only extends ~5-9" from the back of the seat and half as wide). I built it so it can be easily removed and held in place with the seat backs without straps or hardware (photos to come). Since the OEM amp seems to have a sub bass boost, I built a sealed enclosure and filled it to tighten the bass up and keep the power handling high. The Premier sub is rated at 100w rms/ 400w max but the amp is rated at 150w rms mono. I tested it and the sub can handle all the Sony amp has dish out. Nice.

Without question, I can say it fills a huge void from the 6x9s. The 6x9s sound great for bass, but do start to fall off in the sub 80hz range. The little 8" is playing well below 50 (tested by flipping the 50hz HPF back on -- yep, it plays below 50). You can really feel it in your seat. Surprisingly the rear deck DID NOT rattle with the sub -- but now my license plate is (easy fix). Its kind of cool to watch the rear view mirror vibrate.

All that said, I am taking the sub out. What?! Three reasons 1) its a really cool enclosure, but the design flaw is you have to put the seats down to get the sub out. I have 2 kids and 2 kid seats. The double jogger won't fit with the sub installed and its a pain in the rear to remove those child seats! 2) I discovered one channel to my Sony 50x4 amp isn't working. That means I can't run the amp at 50/50/150 as planned and don't feel like like spending another 3-400 on a decent 3 channel amp (though I could use the amp a 150w mono amp and get rid of the unneeded Alpine 6x9s, however, 3) I rarely drive the car without the kids or my wife. The kids sit right next to the sub and I don't want to blow their ears out. I just don't crank up the tunes like I use to (pre kids). My dial rarely sees the 20+ mark. So I might stick to a simple sub-less set up and call it day.

I'll get some photos shot for you guys to see.

 

hmmmm...would like to see the pic of the 8! Anyway, I replaced my 6x9's with jbl's and left the stock amp in the beggining. They were much better than the stockies! The stockies would pop when the low bass hit. Now my set up looks like this https://acurazine.com/forums/audio-video-electronics-navigation-22/dueling-alpine-10s-firberglass-tsx-trunk-boxes-311418/ my newest system is on page 3.

Lets see the pic of that 8 box! I have always wanted to put 8's in the back dash.

 

Here's the set up: http://pg.photos.yahoo.com/ph/c_mill...kgBrDBcMg_QH1g

The sub enclosure is really small. It only measures 12" wide and you only loose ~5" of trunk depth (measured from the top) since its a wedge. Total volume is about 0.43cu' so the 8" hits and falls off -- very tight and punchy, but plays well below 50hz. The box is very secure. It is all built with 3/4" MDF with additional 3/32" MDF glued on the back to secure the enclosure to the seats. Note the speaker wire out the back was just to test it. I have a speaker wire binding post terminal that needs to be put on the back and the box needs to be finished. Like I said, the enclosure so up for grabs (as-is). I have a wood shop, extra wood and an extra sub. I thought it be fun just to see how it sounded ...guess I'm showing my age!