What should I do with the space under/behind the rear seats?

e9Leveque

Well-Known Member
Site Donor
Messages
104
Reaction score
47
Location
Seattle, WA
My car has an amp which was installed in the trunk. It was about 15 years old and the speakers mounted in the parcel shelf were completely blown. I changed those out and built some boxes for them to hang below the rear shelf. At the moment I upgraded the amp and added a subwoofer (both from retrosound). Also wired in the front dash speaker with an Alpine. So the sound is much nicer. But in poking around, seems like I could move these items in the trunk to the area under the rear seats. So a few questions for those of you who have done this:
1. The ECU sits on the passenger side. I need to add the amp and subwoofer, but I’m thinking perhaps both of those should go on the drivers side so as to not have anything near the ECU. There’s enough room on the driver side seat well for both items.
2. See photos of the current state of this area. It’s clear that some of this sound deadening is the original stuff while there are a few areas with some newer pieces. The whole back firewall also doesn’t have any deadening material. Peeling off the ancient stuff seems like it will be a LOT of work. This isn’t a car that I’m trying to fully restore. More that since I’m here, I should do what I can to make it better. Should I add some additional material along the back firewall? Lay more along the floor area back here? Or go through the effort of a complete removal and replacement?
3. This is all part of the first steps of upgrading the rear window motors. Anything else I should do while I’m working in this part of the car? Yes it’s easy to get to but I’d rather not have to undo something like the amp placement if it turns out that I should have done another upgrade while here.

Thanks, I really appreciate all of the info the group provides
 

Attachments

  • IMG_6599.jpeg
    IMG_6599.jpeg
    942.5 KB · Views: 81
  • IMG_6600.jpeg
    IMG_6600.jpeg
    921 KB · Views: 70
  • IMG_6601.jpeg
    IMG_6601.jpeg
    1.1 MB · Views: 73
  • IMG_6602.jpeg
    IMG_6602.jpeg
    980.1 KB · Views: 70
  • IMG_6603.jpeg
    IMG_6603.jpeg
    806.5 KB · Views: 71
  • IMG_6604.jpeg
    IMG_6604.jpeg
    663.7 KB · Views: 74
I’d be mindful of what lies on the other side of wherever you mount the amp, since that will involve screw holes. I would not screw anything to the floor because that may introduce a path for moisture from the road into the passenger compartment.

Sounds like it’s too late now, but the purpose of a speaker box for full range speakers (ie not subs) is usually to prevent the sound from the back side of the speaker from canceling that from the front. Since the back side of the parcel shelf is isolated from the front, a box is not really necessary.
 
Thanks for your input. The speaker boxes were primarily to add a little bass response (likely at frequencies above those of the sub) and also made the trunk a bit cleaner without the bottom of the speakers hanging down. Good point about not drilling into the floor, will have to consider options there.
 
Thanks for your input. The speaker boxes were primarily to add a little bass response (likely at frequencies above those of the sub) and also made the trunk a bit cleaner without the bottom of the speakers hanging down. Good point about not drilling into the floor, will have to consider options there.
Youmight see if you can mount the amp tot he vertical "wall" under the rear seats. IIRC it is about 5-6 inches high, so it might be tight, but you probably don't need a huge amp. You might also be able to just sandwich an amp between the floor and the seat using some sort of heat conductive material to avoid screwing into the floor.
 
The amp is pretty small so I think it might fit on the back wall. The subwoofer is larger but somewhat flat - it’s a bit bigger in surface area than the ECU but about the same height. My only worry about just adhering that to the floor is that over time since it is (obviously) vibrating I wonder if it would work itself free. Likely good for years but long-term…thoughts about welding a few weld nuts down to the floor as anchor points for the 4 corners of the amp where it has its securing points?
 
The amp is pretty small so I think it might fit on the back wall. The subwoofer is larger but somewhat flat - it’s a bit bigger in surface area than the ECU but about the same height. My only worry about just adhering that to the floor is that over time since it is (obviously) vibrating I wonder if it would work itself free. Likely good for years but long-term…thoughts about welding a few weld nuts down to the floor as anchor points for the 4 corners of the amp where it has its securing points?
Welding some anchor points would probably work. Remember you will need to address the weld on the bottom side where it will burn off the undercoating. You could also probably make some brackets that mount tot he vertical wall below the seats and maybe to the trunk bulkhead.
 
Scott, thanks for the thoughtful responses and good point about the undercoating. Once I have time next week to fiddle around with the parts I’ll update but this at least gives me some ideas to work with.
 
Back
Top