overheating amp (NEWB)

[munkeys4u]

as stated my amp keeps overheating:

i have an RF P8002 and two punch HE2

P8002

200w x 2 @ 4ohms

400w x 2 @ 2ohms

800w x 1 @ 4ohms bridged

Punch HE2 4ohm 400w RMS 800 peak

Ive tried several different wiring techniques and cant keep the amp from over heating. Right now i have it wired at 2 channel and i believe at 2ohms.

http://www.rockfordfosgate.com/rftech/wiringwizard.asp?WoofQty=1+woofer&WoofImp=Dual+Voice+Coil+-+4+ohms+x+2&image.x=18&image.y=13

wiring option #1

this is what someone from a caraudio store told me to do. it works great, they sound great but after about 30-35 mins the amp over heats and shutsdown. the amp and the speakers are new. what am i doing wrong? i like to listen to my music loud so i turn the radio up quite a bit but i have the amps' gain turned back about a quarter turn. if i turn it much more than that it has a significant drop in bass.

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[maylar 10+ year member]

Do you have any air flowing across the amp keatsinks to keep it cool?

 

[Jameseypoo 5,000+ posts]

is it in your trunk

 

[munkeys4u]

i have a ford escape and its mounted on the back of the back seat. i leave the seat laying down so the amp is flat and i also mounted it with some 1/2 inch spacers.

 

[johnecon2001 5,000+ posts]

so there is absolutly no air running across the amp, due to the seat laying on top of it...

usually the heat is dissipated off of the top of most amps.. so putting spacers on the bottom isn't going to help the airflow problem. You need to move the amp or sit the seat up.

 

[squeak9798 5,000+ posts]

Well, if the sub has dual 4ohm voice coils, and you have them wired in parallel (as the diagram shows) and the amp bridged, then you have an impedence below what the amp can handle.

 

[tommyk90 5,000+ posts]

What size power wire, where are the gains, bass boost, etc. at?

 

[munkeys4u]

my seat folds foward, so the amp is sitting upright. air does get to it. and i dont have it bridged. im using both channels, that diagram is how i have each speaker set up with its channel.

 

[forbidden 10+ year member]

GROUND WIRE - tell us what you have done to the power and ground wire. What guage are they? Have you done a resistance check on the ground lead? There is nothing wrong with how you have wired the two subs. It is running as a 2 channel, 2 ohm setup. This is fine. If the amp was bridged then you would want a different wiring setup but the net result would still be the same as what you have right now.

 

[munkeys4u]

im using 4 gauge wire for power and ground. i had Tweaters install the amp. now the manuel calls for a 150 amp use which would need 4 gauge wire but the amp only has a connection for one 8 gauge wire. right now i only have a 80 amp fuse on it, not sure if that could be a problem, atleast thats what Tweater employees tell me???? for the ground, its grounded under the seat to the body of the car, a metal portion. if all ineed is the 150 amp fuse and the appropriate adapter, im gona kick myself.......

 

[forbidden 10+ year member]

The fuse would not be part of the problem. All it would do is blow if there is a fault in the amp that the protection circuit cannot control, if there was a short on the power line, or if you drew an excessive amount of current through it continueously. Are you sure this amp does not have 4 gauge power / ground inputs? I have not seen one of these in person but based on all the old Rockford amplifier, they usually had the 4 gauge inputs. They didn't just stuff a 8 gauge in there because that's what they had I hope. You need to get a resistance check done on the ground lead.

I read your post again and to me it seems that everything is working as it should. You have placed quite a demand on this amplifier and if the amp is going thermal after 30 minutes, your playing the amplifer so hard that the thermal protection circuit kicks in to keep the amp from melting. An amp is designed to get hot, but the longer you push it and the louder you want the system to play, the more heat it is going to put off. Not much can be done about this. A cooling fan is going to help but not much. A class D amplifier might have been a better idea for you in this case. Turn the gain down on the amp in the meantime, same with the bass boost if you are using it. By having these turned up excessively will definitely speed the amp in it's way to thermal protection.

 

[munkeys4u]

yeah im sure its just for 8 gauge, which is weird if it requires a 150 amp fuse. but the fuse doesnt blow unless i take the ohms down to low, which i have done and that was the only time it blew.

maybe i am pushing the amp too much. what amp would you recommend to power those speakers or what speaker for that amp. i just like some hard hitting loud speakers.