Strange LFE issue

[Vaughan Odendaa]

Hi guys,

I recently bought an Onkyo 876 receiver. Terrific amp. But there is a problem. On several occasions now, when I'm watching a movie with deep bass (that I am well aware exists) it just disappears. There is no deep bass to speak of.

Then all of sudden a minute or two later the bass reappears and everything is fine. After the bass reappears it's okay for the rest of time. It's like this morning, I turned my AVR on and put on Matrix Revolutions, the end Smith/Neo brawl in the street. There is tons of deep bass in that particular sequence. But the bass literally gets taken away for some reason.

I am pretty certain that this isn't a cable issue. I have not run Audyssey yet but one member at AVS thinks that it might be the DSP chip "not sticking" as it were and that to re-initialize the chip I need to run at least one point using Audyssey. I haven't tried that yet. My speakers are set to small, 80 Hz crossover.

Are there any tests I can do to pin point this issue ? The worst thing is that this issue is difficult to find. It could happen at any time and I don't know exactly how to trouble shoot it.

Regards,

 

[Vaughan Odendaa]

It happened again !

Really not sure what on earth is happening here.

Regards,

 

[Adam]

I apologize for not providing a link (have to get ready for work), but someone else had that issue just recently. Try searching here for it. I don't recall the exact issue, but I think that several things were proposed.

 

[Midcow2]

Does you sub have "auto-on" ?

It happened again !

Really not sure what on earth is happening here.

Regards,

I have a Klipsch sub and the "auto-on" started sporadically working, then just failed all together. I have it set "on" and it works fine now.

The symptoms to start with were very similar to what you are experiencing.

Good Luck!

MidCow2

 

[Vaughan Odendaa]

My subwoofer is set to "on" so it's not on standby.

Regards,

 

[Vaughan Odendaa]

I tried it again now and the same thing happened. No bass. I even had someone listen and it was very evident. Then what I did was I went into the test tone settings and went to the subwoofer. I then got out of the test tone and watched the same scene and voila !

But this is not curing any problem. Because it still happens. But it is interesting that after I go to the subwoofer test tone and then exit from it the bass returns, almost as if I'm "jogging" the receivers LFE output or something weird.

Opinions would be appreciated. Thanks.

Regards,

 

[davidtwotrees]

Do you have another sub to place in the system to eliminate a subwoofer issue?

 

[MinusTheBear]

I notice you have dual MFW-15. Are you not getting output of both during certain scenes?

 

[Vaughan Odendaa]

For now I haven't tried connecting my second MFW-15. But the issue is not the subwoofer because it never presented any issues with my previous receiver.

Regards,

 

[Vaughan Odendaa]

I apologize for not providing a link (have to get ready for work), but someone else had that issue just recently.

I suppose that is good news for me. Did the person sort the issue out eventually ? I'll try searching for a thread related to the issue. Thanks.

Regards,

 

[Vaughan Odendaa]

Guys, thanks for the comments so far.

Regards,

 

[Vaughan Odendaa]

I tried searching for the thread with similar issues but couldn't find it.

Regards,

 

[Cpt.America]

At first I was going to suggest a phasing issue.. but i dont think thats it after reading your descriptions. Does the bass get lower/softer? or is the sub no longer playing AT ALL?

 

[Vaughan Odendaa]

The subwoofer is playing. But it seems as if all the lower bass just gets cropped. Perhaps I need to reset the AVR. Or perhaps I need to use Audyssey to "rejog" the DSP chip which according to another member might solve the issue.

I also don't understand how this could be sub related. I know I've been told by some that perhaps my subwoofer's auto on circuit is faulty even though I'm not using it. But then that wouldn't make sense if the deep bass issue resolves itself without me increasing the volume levels much.

So I'm a little out of idea's at this moment. I haven't tried Audyssey and I haven't tried the reset command on the AVR so I guess I'll have to try those out first and then get back here. Thanks.

Regards,

 

[Vaughan Odendaa]

The issue presented itself again so I disconnected the sub and tried the second MFW-15. Same issue. No deep bass to speak of. So the issue is not with the subwoofers at all.

When I first got the receiver the bass was great. But after a week or two this issue started and I assumed that it was a cable issue. But now this is happening all the time, it's just getting worse.

So I think I'll try resetting the receiver. If that doesn't work then I'm going to ask Onkyo to replace the unit. I've had it for 1 month, I'm hoping they will replace instead of repair it for me.

Regards,

 

[Vaughan Odendaa]

I tried Audyssey, 6 points. Still not resolved. Not sure what else to do to be frank (besides sending it up to them).

Regards,

 

[Vaughan Odendaa]

My Onkyo rep tells me that there could be two issues. Either the processor locked up or my voltage is unstable in my area and that I need to check to see that I'm getting 220-230v.

I told him that my previous amp had no such issues and he said that the 876 has a much bigger power supply blah, blah. What do you guys think ?

Regards,

 

[Gatsby191]

My Onkyo rep tells me that there could be two issues. Either the processor locked up or my voltage is unstable in my area and that I need to check to see that I'm getting 220-230v.

I told him that my previous amp had no such issues and he said that the 876 has a much bigger power supply blah, blah. What do you guys think ?

Regards,

I've had the 875 for almost a year now(the 876 replaced the 875 this year), and the explanation that was given to you by Onkyo, sounds like total BULLSH#T to me. Really sounds like the unit is defective.(IMHO)
Try one last ditch move, and go in to the test tones area and increase the subwoofer level to +1 or +2. I am not too sure if that will help, but it is worth a shot since your next move is to return the unit.
I had similar issues with the volume itself being too low on some movies. I spoke to Onkyo on the phone, and they suggested I increase the levels on each speaker. I increased the test tone levels a bit more on each speaker while keeping the differences that the audessey had set between them, exactly the same as they had been. I've never had a problem since.
I wish you luck! Joe B.