Sub channel blown or??

[SonicRed]

Just installed a brand new Skar SK-M9005D 5 channel amp.

Channels 1-4 work great, however the sub is not working.

I’m getting identical voltage and ohms at the speakers of all 4 channels, but the voltage and ohms are bouncing around on the 5th channel at the wires directly out of the amp.

Is the 5th channel blown???

How to troubleshoot?

Click to read more...

 

[huberoy123 10+ year member]

Hook the sub up to another channel to verify that it is working. Also, try hooking another speaker to the 5th channel to see if it works. That's a start. If the sub works on another channel, and the other speaker doesn't work on channel 5; You probably have a problem Channel 5. Let us know what you find.

 

[Lasherž]

Just installed a brand new Skar SK-M9005D 5 channel amp.

Channels 1-4 work great, however the sub is not working.

I’m getting identical voltage and ohms at the speakers of all 4 channels, but the voltage and ohms are bouncing around on the 5th channel at the wires directly out of the amp.

Is the 5th channel blown???

How to troubleshoot?

A quick and easy way to check for a blown subwoofer is to put a battery between the terminals and listen for a thump. If there's no thump then disconnect it and measure the ohms without the amp, it should be 2/3 to 3/4 of the impedance rating of the speaker. If that's testing alright then make sure your channels aren't swapped on the input for the mono channel and make sure internally to the enclosure the voice coils aren't wired opposite of each other if it's a DVC sub. Opposite channel interference can happen on an LOC pretty easily and the signal will cancel itself out. A common symptom of this is that it gets louder when you disconnect one of the RCA cables. Other than that I'd recommend using ohms law to set the gains for the subwoofer without the sub attached, it should be pretty clear at that point whether the channel functions or not.

 

[SonicRed]

The sub is brand new out of the box.

Is it safe to connect the sub (rms 250w) to a channel pushing out 55w rms?