Appreciate if anyone can give me some advice as I'm really depressed. I have my Pioneer receiver connected to 2 subs at home. It was working fine until one day I heard a loud popping noise from my sub when watching a movie. I realized my sub driver is blown as I can hear scratching noise when pressing on the driver cone.
I was so depressed to learn that the cost to repair the sub (out of warranty) is near $1800 and so I try to find out the root cause. I realized if I replace the blown sub connected to the LFE1 output with another lesser sub, I can hear the random and loud popping sound from the sub driver even when the receiver is powered off/standby. I set the sub gain at 3 o'clock, turn on the Receiver and start playing some low frequency signal, I hear distorted sound as if it is struggling (At that point I immediately turn off the sub knowing it will sustain damage). I did another test to switch the same sub to LFE2 output, and it was all good without any crackling or rattle noise.
I also use different RCA cable and power cable to isolate they are not the cause, so I believe the LFE1 output of the receiver is malfunctioning causing damage to my sub. I'm hoping if I can prove to Pioneer that the receiver is causing my sub to blow, I can at least get them to help paying my repair bill. Really appreciate if anyone can show me how to take measurement of the LFE output.
P.S. my sub is set at +3db at all time.
What an odd fault! That is unusual for a line output. It sounds as if that circuit is letting DC spikes through from the rail voltage.
You really need at least a signal generator and an O-Scope to nail that, and a camera.
I would leave a scope connected to that output and photograph the spikes. Then send LF signals through the receiver with the signal generator and look at the waveform and see if it was clipped and distorted. A distortion analyzer would also be nice to have.
Unfortunately, I think you are right, that receiver blew your sub. I suspect getting Pioneer to pay for the damage will be very difficult. However I would get hold of them pronto and be pretty firm with them.
By the way, it should not cost $1800 to fix any sub driver. It does sound as if the driver needs reconing. No recone kit should cost $1800 and I don't care what it is. Ask the manufacturer for a recone kit. If you are at all handy this is something you can do yourself. What sub is it?
By the way, is the Pioneer still in warranty? If not you will be out of luck all the way around.
