Coincidence Or Issue ??? [Archive] - Audio & Video Forums

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uncooked
01-23-2012, 10:27 PM
A few months ago my Onkyo receivers center channel crapped out. I didn't think to much of it as it was older and had lots of use. So I picked up a Harman Kardon avr-645 for a steal off a guy that barely used it.

Now I have been using the harman kardon for about 2 and a half months with no issues what so ever. When all of a sudden tonight the center channel output is basically completely gone... ! I have swapped speakers around and pretty well tried everything.

So what are the chances I have 2 receivers both fail on the center channel like this..... ?

I'm concerned there may be something wrong with the speaker but why would it take 2 and a half months ???


Any insight would be much appreciated guys. I will probably be dropping the 645 off at a shop to have them take a look at it as this unit isnt quite a "throw away" unit like the old onkyo was.

uncooked
01-23-2012, 10:28 PM
The speaker is a Athena SCT series C1 (8 ohm 91 db)

kelsci
01-24-2012, 10:02 AM
It just might be a coincidence. This is a very nice center channel speaker you own(I looked at it on Athena's website). The only other thing that comes to my mind is some kind of weird problem occurring with this speaker that might be shorting out the center channel amplifier. If you have a ohmeter available, take a measurement to see the DC resistance. In other words, take the two wires of the ohmeter and place each one into the positive and hegative inputs of the speaker and see what reading you get. It sould be from 6 to 8 ohms on the meter. It it reads less than that, say 4 ohms or less, the possibility of a speaker problem may be apparent. I would think the HK could handle a lower impedance speaker but possibly not the Onkyo. What is the rating of speaker ohmage that the HK could handle?

Hyfi
01-24-2012, 11:26 AM
It just might be a coincidence. This is a very nice center channel speaker you own(I looked at it on Athena's website). The only other thing that comes to my mind is some kind of weird problem occurring with this speaker that might be shorting out the center channel amplifier. If you have a ohmeter available, take a measurement to see the DC resistance. In other words, take the two wires of the ohmeter and place each one into the positive and hegative inputs of the speaker and see what reading you get. It sould be from 6 to 8 ohms on the meter. It it reads less than that, say 4 ohms or less, the possibility of a speaker problem may be apparent. I would think the HK could handle a lower impedance speaker but possibly not the Onkyo. What is the rating of speaker ohmage that the HK could handle?

Yeah, the HK can handle 4ohm speakers. I have the 635 and run Dynaudio speakers with it.

uncooked
01-24-2012, 12:28 PM
The Onkyo receiver straight up quit on the center channel. While the H/K was just WAYY quieter than the other channels, hopefully this means there is hope in saving it....

I pulled the H/K out this morning and opened it up just to inspect for anything obviously wrong, I couldnt see anything so I blew it out with compressed air and put the cover back on. I hooked it back up to the center just to see by chance if unplugging it for awhile would help anything. I turned the receiver on and I heard the center speaker pop a few times getting louder each time ( almost like something was charging up) capacitor ??

I used the speaker level TEST feature and the center was actually a bit louder than it was last night but still way quieter than the other channels. I noticed a fair bit of crackles and up and down to the volume during the test as well.

I just dropped it off at a local audio shop for them to have a look at it, hopefully I hear back in a few days and its a easy fix. They were telling me if it DIES its not a good sign and it wont be worth fixing but if it is still outputting it could just be a bad connection / transistor etc....

kelsci
01-25-2012, 10:46 AM
Hi uncooked; I gather that this unit is not under warranty. This sounds like a bad circuit powering the center channel. It appears to be only common to that channel judging by your testing. If it were common to all channels, they would all be cracking and as such would probably mean a power supply problem. Hopefully the audio outfit can fix your unit. I still would do the ohmeter test that I stated if at all possible on that center channel speaker. From your story, the Onkyo too had a crapped out center channel. Perhaps you can take the speaker into that audio place and they could do the ohmeter test.

Mr Peabody
01-25-2012, 03:13 PM
It would seem if it was the speaker that the protection circuit would kick in. However, the issue is quite a coincidence.

Just as a side note Onkyo does fine with low impedance loads, true high current output.

Jack in Wilmington
01-25-2012, 04:34 PM
My Onkyo has no trouble driving my Usher center channel speaker and it's a 4 ohm load. I've noticed that some of my DSP modes send no signal to the center, but I'm sure that's been checked right?

kelsci
01-26-2012, 08:44 AM
Jack, I have a Pioneer VSX-516. Not all the DSP modes weill send a signal to the center channel on this receiver either but at this moment I cannot recall which modes do this.

Hyfi
01-26-2012, 08:58 AM
Thinking back, the reason I replaced my HK with the Integra is that it was doing the same thing, loud popping, crackling noises while watching a movie. Loud enough to scare me into replacing it. But then I was told of a Reset procedure, which I never tried. I have since hooked the HK up in another little 3.1 setup but only used it a few times with no issues now.

BadAssJazz
01-26-2012, 01:34 PM
Applaud him for going through pains of troubleshooting this issue...because with my patience threshold (or lack thereof) I would be looking for BOTH a new AVR and a new set of speakers right now. Just too much of a coincidence that the center channel goes kablooey on two different receivers by different manufacturers.

uncooked
01-29-2012, 11:58 AM
Thinking back, the reason I replaced my HK with the Integra is that it was doing the same thing, loud popping, crackling noises while watching a movie. Loud enough to scare me into replacing it. But then I was told of a Reset procedure, which I never tried. I have since hooked the HK up in another little 3.1 setup but only used it a few times with no issues now.


The shop told me there is issues with the receiver (about 800 worth of parts to repair) But the tech told me he will do a hard reset on the unit and to try that.

Weird enough it has been working fine for a few days now. So there is something wrong with one of the precessing boards maybe ?

I'll see how long it lasts, but atleast its working for now and It gives me time to shop for a new unit.