Amp All Of A Sudden Shutting Off At High Volume?

[Brandon X]

also do you have an eq/ linedriver? sometimes your input signal is too strong. more than likely your subs are wired at 2ohms which is prolly the lowest the amp can take. and when they play at high levels the impedance is dropping below 2ohms causing the amp to shut off... Does it turn back on after a few seconds?

---------- Post added at 10:11 PM ---------- Previous post was at 10:08 PM ----------

try wiring your subs up to 8 ohms and see if it stops the amp cutting off.... it wont be as loud but you will be able to run it full tilt without it shutting off if it is your problem....
if that fixes it, then you need to get a different amp that will run below 2 ohms so that if the imp drops it wont shut off.

Nope no eq/linedriver. The amp doesn't really turn off, it's strange. The power light shuts off on the hard deep bass, and turns right back on as soon as its over. It's frustrating as hell.

 

[JKmotorsports]

When you check for voltage, check it at the connections at the amp, with the amp on roughly half power. Everyone keeps mentioning to check the power wire/fuse, but don't forget the ground. Just like on the power side, a loose gnd will cause resistance and a high voltage drop, especially under load.
If the power light is turning off under high loads then coming back on, then it could be a voltage drop issue rather than an impedance issue with the subs.

 

[gechidan]

I had that same problem with that same amp but I never found the problem......

 

[Brandon X]

Well im definitely going to have my voltage checked. Since I don't have the tool to do that im gonna have my audio guy who installed all this shit check it and fix the problem for me if he can.

 

[nimrodcs]

+1 on checking the ground connection. I put a crappy little system in an old cavalier I had years ago. About a week after installing it, it did the same thing yours did. When the bass would hit, the power LED would turn off then back on. I thought it was the crappy little amp I had, but my brother-in-law found out my ground came loose.

After fixing that, my crappy little system was pumping crappy little beats. All was fine.

 

[blueflamed03]

the amp will play under 2 ohm easily, but two dual 2's, playing will have an actual higher impedance rise.

SSF, is the box ported?

 

[2drhoeon4s]

not neccisarily.... If a coil is bad it will throw the reading off.... also we had mine hooked to an ohm mete while playing andjust like clockwork, it dropped below stable impedance on the heavy low notes and the amp shut off then turned right back on. EVerytime. I rewired my subs up to a higher ohm load and I havent had that problem since. full tilt on any note and it has never shut off since...

Get an ohm meter and check your nominal impedance.turn everything off including the truck. all windows up and all doors closed.unplug the speaker wires from your amp and hook up the ohm meter to them, whatever they rest at is your nominal impedance.

 

[Brandon X]

I'll have to also check the ohms, hopefully my dude has an ohm meter, he should.

Here is the specs of what amp I have and the subs if that helps anyone.

Amp:
# Amplifier Class : D
# Number of Channels : 1-CHANNEL
# Maximum Power : Not Known
# RMS Power Output @ 4 Ohms : 375 watts x 1
# RMS Power Output @ 2 Ohms : 750 watts x 1
# THD: <1%
# Signal-to-Noise Ratio (dB) : >95dB, a-weighted, re: rated power
# Frequency Response (Hz) : 25Hz - 200Hz
# Input Sensitivity (Low Input Level) : 125mV - 5V
# Input Sensitivity (High Input Level) : 250mV - 10V
# Built-in Crossover : Low-Pass
# High-Pass Crossover Frequency : N/A
# Low-Pass Crossover Frequency : 50Hz - 200Hz
# Bass Boost : 0 to 18dB
# Bass Remote : Yes
# Fan Cooled : N/A
# Fuse Rating : 40A x 2

2 of these in a ported box:
# Subwoofer : 12" (300mm)
# Power Handling Watts (PEAK) : 800 Watts
# Power Handling Watts (RMS) : 400 Watts
# Resonance Frequency : 26.1Hz
# Total Q-Factor (QTS) : .527
# Equivalent Volume (VAS) : 3.37cu.ft (95.37L)
# Frequency Response : 25~500Hz
# Outer Frame Diameter : 12-1/2" (31.7cm)
# Mounting Cutout : 11-1/8" (28.3cm)
# Mounting Depth : 6-5/16" (16.1cm)

 

[2drhoeon4s]

yes that is definately the problem... your subs are dual 2 ohms correct? that would mean each sub is wired series up to 4 ohms and then both are paralleled back down to 2 ohm. but they could be sitting at 1.9ohms or 1.8ohms which could cause the amp to shut off.

This is exactly what my problem was. I had 4 dual 4 ohm subs wired to 2 ohms on a 2 ohm stable amp. It worked fine until i played lower notes in which case the amp would cut off for a second or two then cut right back on....I had to rewire the subs to a higher ohm load until i can get a different amp than will handle lower than a 2 ohm load.

 

[Brandon X]

yes that is definately the problem... your subs are dual 2 ohms correct? that would mean each sub is wired series up to 4 ohms and then both are paralleled back down to 2 ohm. but they could be sitting at 1.9ohms or 1.8ohms which could cause the amp to shut off.

This is exactly what my problem was. I had 4 dual 4 ohm subs wired to 2 ohms on a 2 ohm stable amp. It worked fine until i played lower notes in which case the amp would cut off for a second or two then cut right back on....I had to rewire the subs to a higher ohm load until i can get a different amp than will handle lower than a 2 ohm load.

They are dual 4 ohm CVR's. So you're saying the guy who wired them up wired them wrong? It was a different guy who wired them up for me and I thought everything was fine. Everything worked great untill just a week ago, that's what I don't understand.

I went outside and took a picture of how the guy wired them up since I don't know jack shit about car audio so I don't wanna describe it wrong:



The red & black wire is coming from the amp into that first sub. And the clearish redish wire is coming from that first sub to the second sub. Is that right?

I want it wired down to 1 ohm that way I can the most out of my amp as possible you know?