A request for help - particularly to those of you who own Onkyo AV Receivers:

I have an Onkyo TX-NR 3009 9.2 Channel Receiver. This receiver does not process mono analog audio signals in the same manner as it processes stereo analog audio signals. When the audio signal is mono, none of the receiver's surround-sound processing options work properly. The surround-sound speakers either emanate no sound at all, or the sound is distorted and/or at very low volume.

I have conducted numerous experiments with various settings, but the result is always the same. None of the multi-channel processing options work properly. However, both the "Full Mono" and "All Channel Stereo" settings correctly handle a mono signal.

I have discussed this issue with Onkyo technical people, but they have offered no insight - in fact, I believe that they are not aware that the problem exists.

I have a number of "historic recordings" on CDs. The original sound on these CDs is, of course, mono, but the CD provides a two-channel reproduction in which the mono signal is present in both channels. In other words, these CDs have not been "electronically re-channeled for stereo simulation". With a signal present in each channel, even though it is the same signal, the Onkyo's circuits should be able to process the two signals in the same manner as it would a true stereo signal. But, apparently, such is not the case. Somehow, the Onkyo sees a two-channel mono signal differently than a tow-channel stereo signal.

So, I am asking you all - especially those of you who own Onkyo Receivers - to play mono recordings through your systems and note the multi-channel processing results. Do you have the same problem?

Also, please comment about what differences there might be between two-channel mono and two-channel stereo signals, which would cause my Onkyo receiver to respond as it does.

Is this issue confined to Onkyo, or can you replicate this problem with other brands?

I look forward to reading your reports on this thread.

Thanks,

Art

Hey Bro Art, I don't own ANY mono anything, nor do I have an Onkyo receiver.
BUT I think I can tell you this: surround or any type of multi channel matrix works on the DIFFERENCES between the two stereo channel information. In other words, mono CAN'T be synthesized into DD or DTS Neo, etc. Even two identical channels, both having the mono information in them cannot be made into something approaching multi channel.
I hope that is accurate and I hope it helps.
God Bless,
Wayne

Wayne,

Thanks - you may be correct in your comments related to the differences between two stereo channel signals as opposed to there being no difference between two-channel mono signals. However.....

The Onkyo manual differentiates between the Onkyo-proprietary simulations, such as "Orchestra", Studio-Mix", etc. and the other proprietary simulations such as Dolby, NEO-6, THX, etc. The Onkyo manual does not list Mono as a signal source for the non-Onkyo proprietary simulations (Dolby, etc.). But, the Onkyo manual does list Mono as a supported signal source for the Onkyo-proprietary simulations. When I pointed out this difference to the Onkyo technical people, they did not reply with an answer, but said they would look into it and get back to me -- which they never did.

I hope that other folks with mono recordings will provide the benefit of their experiences - Onkyo or otherwise.

I'll stand by for now...

Art