Well, I've been lurking on here for a while seeing what other people are doing stereo-wise so I thought I would post up some pics of the new install and share the info that I gained.

2005 2.5 RS
THE NEW JUNK:
Sony CDX-F7715X
JL 300/4
Boston SL60 (front doors only)
Boston G210
Total Cost: just over a grand.

Phase 1: I installed the Sony deck first with a DIN pocket from SubaruWRX parts to fill the gap. With the new deck and the original (non-premium) speakers, sound quality was still fairly poor - but I could listen to MP3 cd's. Installation was very simple using ISO mounting bracket and new wiring harness. DIN Pocket was also easy although it doesn't mount in the existing bracket holes. I just mounted the deck and used the front edge of that to determine the proper positioning of the pocket and drilled new mounting holes in the factory DIN pocket brackets. While I was doing this step, I removed the sills, kicks, b-pillar covers, drivers side front seat, rear seat, and center console and ran all my under carpet wiring to the trunk for later. I ran the power from the battery along the frame (right behind the A/C line) and through the grommet behind the clutch pedal and secured it under the carpet so that it won't get pinched. I found that there is a set of unused hose clips running along the left side of the floorpan where the floorpan bends up to the sill, these are the perfect size to route the #4AWG power wire.

Phase 2: I installed the subwoofer/amp rack in the trunk. I chose a BA G210 sub because it requires about the smallest box - trying to maximize trunk space. I built a panel the shape of the back of the rear seat and mounted the woofer to the front in the center. I then built the sub enclosure onto the back, making it tall and narrow to allow enough room on the side for the amp. I mounted the unit to the vertical seat support tubes with wood spacers about 1" thick (to allow woofer excursion without the cone hitting the armrest). I built the box somewhat triangular so that the back of the box is vertical instead of angled like the seat so I built a triangular amp rack that would make the amp be vertical as well, this also creates a space behind the amp to hide wire. With the rear seat removed, I disassembled the armrest assembly and removed the upholstery from the fold-down trunk divider. The divider is stamped steel so I didn't want it blocking my bass. I used a jigsaw to cut out the area of the divider that was in front of the woofer (there are two steel supports welded along each side so it was still very strong and rattle free) and reinstalled the upholstery and seat. With the sub and 300/4 mounted and hooked up with 150W @ 8ohms and the factory door speakers, sound quality was not bad. By the way, I used the G210 at 8ohms because the 300/4 has a regulated power supply and works best with the front/rear loads being the same so 4ohms x 2 in the front and 8ohms bridged in the rear, there is no loss of power because this amp is rated at 150W bridged from 3-8ohms.

Phase 3: Home stretch. Installed Boston SL60's in the front doors using IAPerformance thick spacers. The hardest part of this procedure is just getting the speaker wire from the kick panels into the doors. I removed the rubber cable boot from the door and kick panel, disconnected the door wiring plug under the kick panel and pulled the end out of the hinge area so that I could work with it, then I used an electrician's fish tape (expensive coat hanger) to pull the wire through. It is not too difficult to put the hose/grommets back in place. I then covered the speaker mounting area and the exterior door panel (after cleaning off the rally cross dirt) with Dynamat Extreme and mounted the SL60's using IAP thick spacers and no other modifications, I didn't even trim the door panel and there is no cone rattle and the door panel fit on properly without the extended clips. The SL60's are actually fairly small in diameter and I had to use the Boston supplied metal mounting adapter over the spacer to make sure that I didn't have an airgap anywhere. The crossovers fit inside the doors behind the armrest just above the foam filler. Overall a good fit however, if you don't have factory tweeters you will have to fabricate a mount as I did because the Boston tweets have the terminals coming straight out of the back so you cannot mount it directly to the sheetmetal. I simply reinstalled the handle trim/tweeter cover with the door panel off to determine the best location and fabbed up a little metal bracket to mount the tweet, then I covered the bracket with a layer of elec tape to prevent any possible shorting.

Overall I am fairly satisfied. The sub is a little muddy and doesn't hit the very low bass, I may try to put some polyfill in the (currently empty) enclosure and see if that has any effect. The sound is great for rock or jazz with punchy bass but the really low stuff like low stand up bass or electronic music bump is not quite where it could be, I am hoping that I just need to make some minor adjustments and it is not just a factor of my sub/box combo. I am also getting some parcel shelf rattle that I need to track down and hopefully squash with some more dynamat. The SL60's sound great, good mids and highs with the factory default -2dB setting on the crossovers. I left the other switch set to 'on axis' it also has an 'off axis' setting, if anyone knows exactly what this does I would like to know, then I might take my doors off and try the other setting. Power wise a little more power would be good for the sub because, with my music settings, I have to turn the gain down on the fronts to get the sound the way I want it; pushing full power into the fronts I will need more power on the sub to keep up - of course I built everything so that I can, in the future, mount a 300/2 or 500/1 on the other side of the sub-box and use that for the sub and 300/4 for mids/highs exclusively but that is another project for another (hopefully warmer) day.

If you read this far congratulations! Let me know what you think. I hope the pics are in here, I don't know how to put in the thumbs.

Or maybe I do.

 

wow so thats what a trunk looks like. when i open mine all i see is sub box. looks nice.

 

I like the way the trunk looks, I like efficient sub installations.

The main thing that I would do differently, if I were you, would be to install either some mid-bass or coaxial speakers in the rear doorpanels, and provide a dedicated amp for the sub.

Two things will result: a) You will have better sound inside your cabin from having some decent speakers in your rear doors, you can't go wrong with either of those two possibilities. b) The sub sound will greatly improve, and you won't be straining your amp so much.

Another thing to keep in mind regarding the sound of that sub, it seems that you didn't pick this sub to produce really deep-hitting bass. There are better subs out there to give you deeper, harder-hitting bass. The sub you picked (you know this) is better-suited for great detail and accuracy.

I would also move the amps to the other side of the sub enclosure, so as to offset the vehicle's weight from you being in the driver's seat.

I had a small sealed enclosure installed directly against the back of the rear seat on the driver's side of my STi (which doesn't have your access door), firing sideways, with the two amps that are in the middle and on the passenger-side, all against the rear of the back seat. The two amps are both heavier than the sub and its enclosure, so the weight balance works better.

I'm sure you could figure out a nice bracket system to put the amps on the passenger side.

Also when you're filling up the sub enclosure with insulation, make sure that you have that thick white insulative cloth that separates the inside of the loose filling from the backside of the driver.

 

Sub boxes generally benefit from a lb per cu ft of polyfill. Yes it will help get rid of the mudiness.

If you want to add rear fill....whatever. I personally hate it and none of the systems I install use it. And I have to fix ALOT of "professionals" work.

 

Group B. I wasn't really considering weight balance, the position of the amp was just for a slightly shorter power run. I was basically planning for a possible future upgrade of a dedicated amp on the right for the sub and using the rear channels on the other for some 5.25's in the rear doors later. This was all the gear I could afford at one swipe tho! And yeah, I chose this sub for detail and accuracy but sometimes the frosted side of me likes to pound it a little just for the fun of it. Overall I like the sound, I just didn't realize how much more power I would need for a real car cabin and a small sealed enclosure - my tacoma has a 150 watts on the stealthbox and it is much louder. I will need to save my pennys and eventually get a full 300 watts to my sub in the RS. Equinn's got more bass but I've got more trunk! Life is a compromise sometimes. Thanks for the input.