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Rear 6.5" replaced by 8" custom install!

3K views 9 replies 6 participants last post by  ultimatemj 
#1 · (Edited)
Friend had funds to upgrade door speakers and rear speakers, so I got him to follow this up grade. Just replaced the front 6.5's with a set of kickers. Rear was the real thing. First removed and covered parcel shelf with black leather. Ensuring speaker mounts were blacked out also. While shelf was out used sawz all and removed the little humps that sit below the 6.5's. pretty much giving a flat mating surface. Made template of underside of deck and transferred to 1/2" mdf. Cut out template and also made 6.5" holes that line up with the mounting holes in the shelf. Covered mdf with gray felt fabric almost matching trunk. Before reinstalling shelf drilled 1/4 inch holes through metal deck and mdf for securing bolts to go through. Used 6 screws and nuts to secure mdf to underside of deck. Used black silicone type caulking to seal around exterior of Mdf. Reinstalled rear shelf. Here's the good part. Used high density expanding foam to seal area from 6.5" hole in mdf to 6.5" inch hole in shelf. Placed duct tape around outline of opening in top on shelf and on the underside of the mdf. Just to keep foam from expanding onto surrounding materials. Remember to place plastic on floor of trunk to catch any foam. Sprayed foam into cavity between shelf and metal deck and mdf. Just enough to get it to come out so the cavity and can be trimmed off with a long knife, to make a perfect cylinder when hardened. Once cut and shaped used brush on plasti coat to black it out and smooth out foam surface. Forgot to mention loctite on bolts so they don't vibrate loose. Rounded heads of carriage bolts sink Into mdf a little so not really noticeable. Remove duct tape. Small bead of clear silicone around mounting surface of 8's, screwed into mdf. Just about as air tight as you can get, using trunk as IB. Ran wires along back of wall, flat to mdf. Invisable unless you look under deck!
 
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#7 · (Edited)
The particular drivers (Image Dynamics Id8d2) may have "worked better" in a sealed box, but my goals were a combination of SQ, stealth, and maintaining as much trunk as possible. I actually gained space over the stock HK sub and their parameters really do work fairly well "free air" (or infinite baffle). I'd do it again for sure :thumbsup:
 
#10 ·
In general cutting is messy and you have to pay attention to where the "double layer steel" is located...but I'd do it again :D

If you are willing to give up some of your trunk, you could just hang them underneath and play them through the existing openings.
Auto part Suspension Vehicle Engine Ceiling

I believe the "rule of thumb" for subs is the opening needs to be atleast 60% the size of the woofer :hmm:
 
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