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Old 08-02-2009, 05:36 AM   #1
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Default Cool Your Jets (er, amp) Boy

Anyone have an aftermarket amp in their trunk? Not all the time, but once a month or so, I'll go on a "long" trip, you know, more than 20 minutes, and my amp will sometimes overheat, and cut out. It's mounted in my trunk.

Anyone found a simple answer for this? I guess there's no sin in a fan, if it goes out, the normal thermal protection will work, but... I'd love a way to get "natural" air flow from driving, without running the risk of getting water in there.

I do always have the top down... Perhaps scoops by the fuel tank would work.

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Old 08-02-2009, 08:43 AM   #2
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That amp looks ENORMOUS>.. are you driving more than just that sub with that {i hope so}.. If not , downsize. let a smaller amp do the work that a larger amp does without all the excess overkill.
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Old 08-02-2009, 09:33 AM   #3
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I have NEVER with a single one of my cars had an amp cut out due to overheating.
Perhaps you are overpowering your sub and its causing the amp to cut out, that happened to me before. I unbridged the wires and turned down the amp power output and all was well again. I have a 750 watt pioneer amp powering a 500 watt kicker sub in the subaru and I've gone on multiple 4-5 hour drive's with absolutely no problems.
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Old 08-02-2009, 11:36 AM   #4
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Mine is mounted to the floor and has a built in fan, which is usually covered up by a large bag, never had it overheat.

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Old 08-02-2009, 11:39 AM   #5
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abe, what's the amp rated (RMS) and what's the sub rated (RMS/ohms)?
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Old 08-02-2009, 11:59 AM   #6
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As everyone has said, that amp is far too large. If you want to keep your amp crazy cool, pick up a Bazooka amplifier that is CHILL compatible, and then buy a CHILL kit. It's a full coolant cooled amplifier system. Otherwise, I mounted my amplifier on the deck behind the seats. With the top down you get a great breeze over it.

On that note, I've never had an amp overheat.
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Old 08-02-2009, 12:01 PM   #7
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I have two amps mounted to a panel in the well of the trunk and usually covered with my toneau. Never had either cut out. A simple test would be to place your mount ont he floor of the trunk and see if it still overheats. The way you have it mounted right now sure isn't helping the amp cool properly. Heat rises. The heat from the fins on your amp is going right back into the amp.
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Old 08-02-2009, 12:02 PM   #8
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I had my oldschool Rockford amp and my current MTX go out due to heat when I had them in the spare tire well and a false floor over them and my golf bag on top. I'm moving them to the same place as AbeFM and will add a couple cpu heatsink fans with a bosch relay just to get better airflow over the heat sink.

The RF was pushing two subs running 2 ohms though. The MTX simply is getting no airflow over the heatsink where it is now plus it's getting heat from the other MTX running my fronts which isn't being stressed nearly as much.

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Old 08-02-2009, 12:03 PM   #9
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bitches ain't **** but hos and tricks.
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Old 08-02-2009, 12:04 PM   #10
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Quote:
Originally Posted by AbeFM View Post
Anyone have an aftermarket amp in their trunk? Not all the time, but once a month or so, I'll go on a "long" trip, you know, more than 20 minutes, and my amp will sometimes overheat, and cut out. It's mounted in my trunk.

Anyone found a simple answer for this? I guess there's no sin in a fan, if it goes out, the normal thermal protection will work, but... I'd love a way to get "natural" air flow from driving, without running the risk of getting water in there.

I do always have the top down... Perhaps scoops by the fuel tank would work.

Mine is mounted in the same spot and I have the same problem. One of these days I'll probably mount a fan to it or something similar. I have considered going to d-class for stealth and/or less need for cooling.
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Old 08-02-2009, 03:33 PM   #11
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Mine is mounted inside the rim of the spare tire, and I've had it overheat only on a road trip where the trunk was packed full and it was near 100* with direct sun.

Lick on these nuts and suck the dick.
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Old 08-02-2009, 04:28 PM   #12
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Yeah, it doesn't overheat much, but it does occasionally - when it's hot out, a long drive - I think the diff and the exhaust aren't helping, and yes, it's at the top of the trunk. Maybe an exhaust vent? Could put a flip up license plate. :-)

The amp is 1200 watts, 5 channel - it might be overdriving the other speakers, but not the woofer, which like (I think) a 350 watt with 400 driving it, and it's never up all the way, I would die. :-) But it is when it's loud I have issues. I have a pair of 70 or 80 watt infinities in front and some 15 year old 35 watt pioneers by the gas tank to fill in the sound a bit, plus bose tweets in the doors.


I guess I should look at turning it down? It's certainly close as is, I'm not way overpowering anything except those pioneers, and they are turned down.

One more pic, just cause I like how the speaker came out:
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Old 08-02-2009, 05:47 PM   #13
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wattage is relevant but not useful without the subs impedance ratings (and wiring if it's DVC).
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Old 08-02-2009, 06:02 PM   #14
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360 watts @ 2 ohms; class-d sub amp ftw!
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Old 08-03-2009, 04:58 AM   #15
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Put it on the floor. Obviously heat is not dissipating as effectively by having it on it's side. How about an amp rack w/ fans?
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Old 08-03-2009, 10:41 AM   #16
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ok since abe will never answer me, he's probably overdriving it and it's overheating. probably is normally marginally OK, but as soon as it has no cold thermal sink, it's just getting too hot.
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Old 08-03-2009, 02:34 PM   #17
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yeah - it doesn't really contact the rear wall much - its all convective/radiative.

Um, it's a woofer, DVC (2x4ohm in parallel), rated at 350W @ 2 ohms, and the amp is rated at 400 @ 2 ohms. I *can* double check the woofer specs, but I remember doing it before and thinking it was just right for the application, including the nice high cut-off frequency.

Maybe I need thermal straps! Actually, this is one case where I'd feel ok using fans... the amp is already marginal and has a safety, so if the fans fail I'm just back where I started.

But I really want to make a vent. Maybe through the tail lights? Something to just let the car moving provide the airflow (it's only ever overheated on the freeway)
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Old 08-03-2009, 02:55 PM   #18
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TS-W306DVC - which is most likely 400w RMSm but might be 350 - there was a model change and I'm not 100% clear which spec is with which part. I don't think you can tell from the outside which is is, and I've yet to find any photos which show the label.
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Old 08-03-2009, 04:39 PM   #19
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Like others have said, your amp, being upside down is trapping all the heat it makes. A TINY crossbreeze will probably fix it, just like mounting it right-side up so the heat can radiate out of the heatsinks. Heat goes UP.

You could try mounting it on the bumper side at a better angle, just let that heat go up.
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Old 08-03-2009, 04:41 PM   #20
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Quote:
Originally Posted by AbeFM View Post
yeah - it doesn't really contact the rear wall much - its all convective/radiative.

Um, it's a woofer, DVC (2x4ohm in parallel), rated at 350W @ 2 ohms, and the amp is rated at 400 @ 2 ohms. I *can* double check the woofer specs, but I remember doing it before and thinking it was just right for the application, including the nice high cut-off frequency.
the woofer rating is more of a "thermal guideline" than a power consumption value. if it's playing low enough in a small box and the volume is high enough, it'll draw more than the amp can put out. sounds like you just need more amp headroom.
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