No sound from subwoofer

[Gerry W]

I have an Onkyo TX-SR800 and a Klipsh KSW12 Recently the sub stopped working. I confirmed that the sub is operational and the cable to the receiver pre output are OK. I checked all the setups and they are OK including the SUB ON setting and speakers set to small. When I run the speaker Level Cal I hear the pink noise from each speaker except the sub. No sound from the sub. Any suggestions would be appreciated. How can I test the preamp???

 

[lovinthehd]

How did you test the sub was operational? The cable? Try a reset of the avr? What other gear do you have to test the pre-out with?

 

[sterling shoote]

Are you using the preamp's test tone function or the test tone function from a Universal Player? Some Universal Players to not carry a tone to the sub. Also, check sub volume level setting and crossover setting.

 

[TLS Guy]

You said you confirmed the sub was working. How did you confirm that?

If you are certain your sub is working, then do a hard reset of the Onkyo back to factory defaults and set it up again. If that fails, it is new receiver time. That unit is nearly 20 years old and is now well passed its expected lifespan.

 

[Gerry W]

How did you test the sub was operational? The cable? Try a reset of the avr? What other gear do you have to test the pre-out with?

The sub & cables were tested on another receiver. The receiver was reset and re setup. The only test gear is a DVM

 

[Gerry W]

Are you using the preamp's test tone function or the test tone function from a Universal Player? Some Universal Players to not carry a tone to the sub. Also, check sub volume level setting and crossover setting.

The test tone comes from the receivers setup menu for level cal. The test tone works on all speakers except the sub. The sub was tested with another receiver so the volume and crossover settings are not the problem.

 

[Gerry W]

You said you confirmed the sub was working. How did you confirm that?

If you are certain your sub is working, then do a hard reset of the Onkyo back to factory defaults and set it up again. If that fails, it is new receiver time. That unit is nearly 20 years old and is now well passed its expected lifespan.

The sub was tested on another receiver. The receiver was reset and set up again. Any suggestions on testing the pre amp??

 

[sterling shoote]

Why test the preamp, you've already determined the preamp is broken. I suspect it just needs fresh solder at sub output.

 

[lovinthehd]

It does sound like for some reason your avr's sub pre-out has failed in some way and likely either needs repair or time to look for a new unit.

 

[AcuDefTechGuy]

So you were able to get pink noise for the Sub using another AVR, but just no pink noise for the sub using the Onkyo AVR?

Then the Sub Output is broken in the Onkyo.

Use the Onkyo Speaker Main Left and Main Right Outputs (speaker wires) and connect to the Klipsch Speaker-In speaker posts. Then connect the Klipsch Speaker-Out speaker posts to your speakers.

So Speaker Wires from AVR to Subwoofer. Then Speaker Wires from Subwoofer to Speakers.

 

[lovinthehd]

So you were able to get pink noise for the Sub using another AVR, but just no pink noise for the sub using the Onkyo AVR?

Then the Sub Output is broken in the Onkyo.

Use the Onkyo Speaker Main Left and Main Right Outputs (speaker wires) and connect to the Klipsch Speaker-In speaker posts. Then connect the Klipsch Speaker-Out speaker posts to your speakers.

So Speaker Wires from AVR to Subwoofer. Then Speaker Wires from Subwoofer to Speakers.

If you do connect it this way, you'd need to set your speakers as large since you're no longer able to use bass management in the avr. Your sub manual indicates by using the speaker level inputs/outputs that a high pass filter for your speakers at 100hz is applied with a 6dB slope.

 

[mtrycrafts]

The sub & cables were tested on another receiver. The receiver was reset and re setup. The only test gear is a DVM

Are you talking about two different receivers here? Did you use that internal test tone in the other receiver to confirm cable and sub works?

If so, your issue as stated by others is the receiver that is not energizing your sub. Simple.
Then, also as stated, need to troubleshoot why that is, settings? or some other issue.

 

[Gerry W]

So you were able to get pink noise for the Sub using another AVR, but just no pink noise for the sub using the Onkyo AVR?

Then the Sub Output is broken in the Onkyo.

Use the Onkyo Speaker Main Left and Main Right Outputs (speaker wires) and connect to the Klipsch Speaker-In speaker posts. Then connect the Klipsch Speaker-Out speaker posts to your speakers.

So Speaker Wires from AVR to Subwoofer. Then Speaker Wires from Subwoofer to Speakers.

Thanks

 

[Gerry W]

Thanks

 

[Gerry W]

Are you talking about two different receivers here? Did you use that internal test tone in the other receiver to confirm cable and sub works?

If so, your issue as stated by others is the receiver that is not energizing your sub. Simple.
Then, also as stated, need to troubleshoot why that is, settings? or some other issue.

Thanks for the response. Yes 2 different receivers. Yes to the test tone. If it is the pre amp I would try to repair it.

 

[mtrycrafts]

Thanks for the response. Yes 2 different receivers. Yes to the test tone. If it is the pre amp I would try to repair it.

As others have indicated, it might be the way it is set up?

 

[Pogre]

Thanks for the response. Yes 2 different receivers. Yes to the test tone. If it is the pre amp I would try to repair it.

Just to be sure, did you test in the same location? As in, was it moved or transported after you tested? Is there any chance something might have happened to it in between testing like an interruption in power?

It does sound like it's an issue with the sub out on your avr, I'm just ruling out any other possibilities.

 

[lovinthehd]

If it is an issue with the avr that you can repair why are you asking us?

 

[TLS Guy]

Thanks for the response. Yes 2 different receivers. Yes to the test tone. If it is the pre amp I would try to repair it.

How to you plan to do that? Unless you have a service manual and test equipment plus experience and the right skill set you will not fix it. A standard DVM will do more harm than good. For equipment like this you will need a high impedance amplified meter. You will need a signal generator and o-scope at a minimum.

I suspect that the failure is in the low pass circuit. Most likely the chip at the heart of that circuit has failed. Replacing that on a modern board with surface mounted components will require a special skill set. The next issue will be tracing whether said chip is still available and if not, hunting down if anyone knows if there is a substitute.

Lastly serving gear if you are not experienced is very dangerous as it pretty much always involves working on open live equipment.

I have a feeling that if you had the skills required you would not be posting on forum like this for guidance, as you would already have the unit on the test bench with probes to the appropriate equipment guided by an official service manual.

If you are not experienced for your safety, please stay out of the unit. If you are experienced, please keep us updated.

 

[AcuDefTechGuy]

If you do connect it this way, you'd need to set your speakers as large since you're no longer able to use bass management in the avr. Your sub manual indicates by using the speaker level inputs/outputs that a high pass filter for your speakers at 100hz is applied with a 6dB slope.

Good catch.