Amp under passenger seat - where to ground?
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This is a discussion on Amp under passenger seat - where to ground? within the Interior Mods forums, part of the Tech & Modifying & General Repairs category; For those who have their amp(s) mounted under the front seat(s)..... I plan on putting mine under the front passenger ...

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    Amp under passenger seat - where to ground?

    For those who have their amp(s) mounted under the front seat(s).....

    I plan on putting mine under the front passenger seat as it will not get moved as much as the front, if at all. That should limit any wires rubbing or other potential damage. Anyway, just wondering where you grounded your amp.....on an existing chassis bolt, drilled in somewhere....etc?

    Thanks!
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    Registered User jd92677's Avatar
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    I have not mounted an amp under the seat, but a perfect ground would be a seat rail bolt.
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    UnBanned Sinister's Avatar
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    They say you're not supposed to... but I agree. The seat bolts are stout and bolt right into the "frame" (if you can call it a frame)
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    He simply abides. SD_GR's Avatar
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    You are running power there anyway. If you don't want to use the seat bolts (and I can understand why) then just run a ground wire from the front and ground every component to the same point, somewhere in the dash.
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    Supporting Member mjboudreaux77's Avatar
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    Quote Originally Posted by SD_GR View Post
    You are running power there anyway. If you don't want to use the seat bolts (and I can understand why) then just run a ground wire from the front and ground every component to the same point, somewhere in the dash.
    Depending on the power of the amp - this isn't a great idea. You want the absolute best ground you can get - the frame is ground so bolt right to that (seat rails are fine). You don't want IR drop on a GND wire from the amp.

    Also - my Kenwood mono amp never got hot, so I could see it being ok under a seat, but it was a class D sub amp. If you are powering anything besides a sub, you won't want a Class D (they are very efficient, but don't reproduce sound that great) - so yours might get hot if it has a high enough power output.
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    It's an Alpine MRP-M500, class D mono amp, just powering a single sub. Neither of my Alpine amps in my other car get hot. I can touch them without sizzling after a good audio workout.

    Rule of thumb is GND no longer than 18", so it's gotta be somewhere close, and maybe my eyeballs are off, but it is more than 18" from the seat to the firewall.
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    Supporting Member mjboudreaux77's Avatar
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    Quote Originally Posted by GEARJAMR View Post
    It's an Alpine MRP-M500, class D mono amp, just powering a single sub. Neither of my Alpine amps in my other car get hot. I can touch them without sizzling after a good audio workout.

    Rule of thumb is GND no longer than 18", so it's gotta be somewhere close, and maybe my eyeballs are off, but it is more than 18" from the seat to the firewall.
    Your MRP-M500 should be fine under the seat - they really just don't get hot. Why though? Is the sub going in the trunk? My Kenwood was powering a single 10inch in a sealed - there was plenty of room to mount the amp in the trunk without giving anything up. I ask because if the sub is in the trunk, now you are running audio speaker wires a decent distance to get to the speaker. You will probably need 12-14 gauge at smallest for that distance. I also found I needed to "tweak" my settings (LPF, gain, etc etc..) to get the sound just right. That might be a bit of a pain under a seat.
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    yes, the sub is going in the hatch area. I have an Audio Integrations enclosure on order already. I want to keep the sub out of the hatch area for a couple reasons: 1. I often am throwing my hockey bag in the hatch, and having that sitting on the sub is not ideal, 2. I removed the cargo area cover so it is open and visible. The less someone can see, the better. Plus, under the seat, the amp is not going to get kicked (my kids legs aren't long enough) or jostled like it would in the hatch. And I've got lots of large gauge wire in the basement from running home stereo to different rooms.
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    I didn't realize you had the hatch.. now I get it.

    Good luck. Its going to sound awesome.
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    I have my amp under the front passenger seat. I ran the ground under the carpet and to a bolt under the back seat. The bolt was hefty and connected to the sheet metal. Seems to be working great thus far, and this was even my first amp install EVER.
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    Registered User Heide264's Avatar
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    Just a warning, in my van the seat bolts couldn't be used as (reliable) grounds. They were spot welded to the frame on the bottom, and as the car aged, it would lose conductivity. Just a warning.

    I actually cut a small U in the carpet to ground it in that car. Just be careful about drilling straight down - never know where things are hiding right under the car body (fuel tanks?).
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    Moderator Donkey's Avatar
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    Unfortunately unibody construction sucks for ground continuity. Grounding to the frame rail is a good idea as it usually is a pretty solid ground. You want the ground wire to be as short as possible to keep resistance low. I usually make it a habit to run a pretty large ground from the battery neg to the fire wall for in cabin electronics.
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    I realize this is an old thread, but to anyone searching this topic, there is a factory ground point underneath the passenger seat.

    If you don't want to use this bolt, there is a hole right next to it that you can bolt for ground. There is paint there, so sanding a little around the hole may be advisable (although the factory ground is on paint, so it might be fine).

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    I used the factory ground point for my Alpine PDX 9V under the passenger seat.
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