Speaker mount in side rear quarter panels - '72 Mach1


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Well-known member
Feb 5, 2024
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My Car
1972 Mustang Mach1
After removing my rear quarter panel wall panel there appears to be quite a bit of space for mounting a speaker. Potentially forward facing 4x6"in and/or below the arm rest side-facing maybe 5 or 6" round? I'd go with some plastic panels and reinforce them on the interior so they could let the speakers do their thing without creating a new rattle source. Any thoughts on this placement?

Another thing I'm considering would be a custom corner sub box on either side of the trap door. No permanent mods to the metal but just flush looking with matching carpet.

BTW - I probably will put the 4" door speakers back in and the wimpy center speaker in the dash pad mostly to help with sound 'fill'.

Hello - yes, the exhaust sounds great, just wanted to add some driving tunes to go with it :). My interior rear quarter panels aren't original and are quite bad so I was going to replace them anyways.
Back in the day, I usually left my rear seat folded down. I used speaker boxes that fit 6x9 speakers and put them on each side of the trapdoor and used Velcro to hold them in place on the carpet. Good sound without butchering the panels. With the rear seat up, they would sit behind the seat back, tilted up.
Perfect - that is what i was thinking also if I end up adding speaker boxes - I think I could make them look decent.

But I just got a message earlier today about a sale of second trap door with speaker cutouts from a parts vehicle. Would be good for a larger 3-way or a couple modest subs but not sure how I'd stop it from rattling.
This is my speaker box behind the rear seat. The car had these when I bought it. I eventually changed the speakers with 6x9 Kickers and added the pipe seen in the picture. The pipe added a deeper bass. if interested, there is a whole science and information out there about the volume and length for this pipe. I originally had the boxes velcroed to the carpet which worked well. As I got more into racing, now I have them attached with small L brackets and they don't move at all. I leave them there since they only add a few pounds that I don't care about.

PS: I left the Pioneer grill to add a classic touch to the setup