Amp overheating?

[adamc11]

Hi Guys,

I have a JL audio 300/4 amp. I used to have it mounted under the parcel tray in my VY SS but have mounted it on the back of my new cars rear seat (on top of the boot carpet).

I cannot remember how hot it was in my SS, but in my new car it is so hot you can only hold your finger on it for a few seconds.

Would mounting it under the metal parcel tray which would have helped it air better compared to mounting it on carpet make such a huge difference in temp? Personally I don't think so.

Anyone with amps... let me know if yours gets hot.

Thanks,
Adam

[holdenboy]

Its normal for an amp to get warm, but not as hot as your's is getting. More info on the install would be great, like what else has changed from the SS? Like power cabling same size, is the amp running the same speakers/subs etc.?

Under the parcel shelf isnt the best spot for an amp, but usually most have no problems.....only occasionally going into protect mode from over heating. The back of the rear seat isnt a bad location, IMO better than the parcel shelf.
I think theres something else going on here apart from the install location.

[Vg-ute-mad]

I would leave it where it is... Mounting it under the parcel tray will be worse, as it would be mounted upside down. And as you know, heat rises.

Just curious, but is it dropping in volume due to being hot?

[adamc11]

Its normal for an amp to get warm, but not as hot as your's is getting. More info on the install would be great, like what else has changed from the SS? Like power cabling same size, is the amp running the same speakers/subs etc.?

Under the parcel shelf isnt the best spot for an amp, but usually most have no problems.....only occasionally going into protect mode from over heating. The back of the rear seat isnt a bad location, IMO better than the parcel shelf.
I think theres something else going on here apart from the install location.

I was using a kicker wiring kit in the SS and am using a cheaper Sony one in the mazda.

Currently i am using a 60amp fuse with 8 gauge power cabling. It is a 4 channel amp and currently i have 4 speakers (front and rear) sharing 2 channels, and WILL BE (currently 2 channels are empty) plugging my sub into the other 2 channels.

I unplugged the RCA's from the back of the amp and drive for about 5 min and noticed it was still very hot... therefore i am thinking it is a power thing. However, after pluggin the RCA's in again and pumping the stereo a bit it got even hotter.

What do you think? It wouldn't be because i am running 4 speakers over 2 channels? I did this with my SS and it was fine. Actually the SS speakers were bigger... the mazda has 2 x 4" and 2 x 6".

Thanks,
Adam

[adamc11]

I would leave it where it is... Mounting it under the parcel tray will be worse, as it would be mounted upside down. And as you know, heat rises.

Just curious, but is it dropping in volume due to being hot?

I don't think so. It isn't getting very loud but i havn't set gains properly and i think i have the voltage set to high instead of low (i'm using low level outputs from my HU).

[holdenboy]

Hmm, i was going to say that running those 2 channels at 2 ohm (2 speakers per channel) could be the problem, but as you said you were doing the same in the SS and didnt have a problem.
Was the kicker wiring kit 8AWG also?

[adamc11]

Hmm, i was going to say that running those 2 channels at 2 ohm (2 speakers per channel) could be the problem, but as you said you were doing the same in the SS and didnt have a problem.
Was the kicker wiring kit 8AWG also?

I think the kicker was 4 awg. I will try unplugging 2 of the speakers and see how it goes. Also, the thermal light on the amp has not come on.

[holdenboy]

Yeah i was going to say try unplugging two of the speakers, or if you can run the rear speakers off the other two channels.....probably wont make a huge amount of difference though.

Could also be the 8AWG, the amp might not like the voltage drop and is working harder with the lower voltages maybe?

Anyway, try 2 speakers....if its still getting too hot to touch then upgrade to 4AWG. Do your earth too.

[adamc11]

Yeah i was going to say try unplugging two of the speakers, or if you can run the rear speakers off the other two channels.....probably wont make a huge amount of difference though.

Could also be the 8AWG, the amp might not like the voltage drop and is working harder with the lower voltages maybe?

Anyway, try 2 speakers....if its still getting too hot to touch then upgrade to 4AWG. Do your earth too.

I might go ask the guys at JB as that is where i got the amp and was recommended the kicker kit.

This is the amp: JL Audio 300/4v2 Amplifiers - Car Audio Amps & Amplifiers
This is the amps manual: http://mobile.jlaudio.com/pdfs/Slash_amps/300_4_MAN.pdf

Quotes from the manual:

“Thermal” (Red): lights to indicate that the
amplifier has exceeded its safe operating
temperature, putting the amplifier into a selfprotection
mode, which reduces the power
output of the amplifier. The red light will shut off
and the amplifier will return to normal, full-power
operating mode if the heat sink temperature
drops back to a safe level.
(this hasn't happened yet)

The 300/4's “+12 VDC” and “Ground”
connections are designed to accept 8 - 4 AWG
power wire. 8 AWG is the minimum
recommended power wire size for
this amplifier.

[holdenboy]

Yeah, i know the 300/4s, great amp

Anyway, its a good sign that it hasnt gone into protect.....maybe it did run that hot in the SS and you never realised / checked it?
I wouldnt use 8AWG to power an amp like that, 4AWG is more ideal. I know youre not really pushing the amp that hard either, but its just something to think about in the future if this cant be solved.
Where did you ground the amp?
When you say you have the voltage set to high instead of low, you mean the input level? I'd be putting that on low if youre using RCAs from the head-units preouts too. Not sure if that'll make any difference though.

[adamc11]

Yeah, i know the 300/4s, great amp

Anyway, its a good sign that it hasnt gone into protect.....maybe it did run that hot in the SS and you never realised / checked it?
I wouldnt use 8AWG to power an amp like that, 4AWG is more ideal. I know youre not really pushing the amp that hard either, but its just something to think about in the future if this cant be solved.
Where did you ground the amp?
When you say you have the voltage set to high instead of low, you mean the input level? I'd be putting that on low if youre using RCAs from the head-units preouts too. Not sure if that'll make any difference though.

I grounded the amp straight into the chassis in the boot. They say that 8awg is the minimum so it should be okay but as you said it's something i can try if all else fails. Yes i am referring to the input level... i will double check its set right and if not see if changing it does anything.

I'm not sure how i'm going to wire the HU and amp(s) up. See: Head unit and amp help

I'll let you know how it goes. Thanks for the help