Sherwood receiver stereo/DSP issue..

Discussion in 'AV Receivers' started by Matt:Brunmeier, Jul 17, 2005.

  1. Matt:Brunmeier

    Matt:Brunmeier Stunt Coordinator

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    I have a Sherwood RD-7106 and from a stereo source (like an iPod or a CD player) it seems only capable of playing in stereo (that is.. just the front two speakers). Shouldn't it be able to do all 5 channels even from a stereo source? None of the DSP modes seem to work correctly.
     
  2. Matt:Brunmeier

    Matt:Brunmeier Stunt Coordinator

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  3. Matt:Brunmeier

    Matt:Brunmeier Stunt Coordinator

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    REVELATION!

    I've learned that there is sound coming from all the channels, but from the rears it's so silent that I need the volume at MAX to hear it at a whisper. Anyone know what could cause something like this? The channel isn't turned down, it's the same as the fronts.
     
  4. LanceJ

    LanceJ Producer

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    Matt: not all DSP modes create a lot of activity in the surround channels; and how the music was recorded has a significant impact on the quality of the effects the DSP chip can generate. Most DSP chips look for out-of-phase* information in the stereo signal and work with that with varying degrees of success. The worst case scenario would be a pure mono signal: in this case there can be no out-of-phase info so most DSP choices do nothing.

    As a rough rule, I have noticed usually the more "out there" or heavily produced the music gets, the more effects one hears.

    * the chip looks for signals in both channels that are identical but their phase is different i.e. a guitar note that is positive in the right channel but negative in the left one. This can happen naturally from the venue's own reverberation effects (the mic picks up the initial guitar note then the reflected note a moment later >>> out of phase) or purposefully added by the mixer. And the amount of phase difference--anything between 0 degrees and 180 degrees--also affects the final surround channel output you hear. Of course the DSP chip's software can have a huge effect too if the designer wanted it to. For example my Technics' SA-DA8 receiver has a mode called "simulated surround" that can take any kind of signal and (if you crank up the delay past 50ms) make it sound like I am listening inside a giant coffee can! Good for a laugh but that's all. BTW: DPLII, DTS:Neo & Logic7 use much more sophisticated software to do their thing.
     
  5. John S

    John S Producer

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    Matt, it looks like it does not have an All Channel Stereo mode? 5 to 7 Channel???

    I'm not sure I grasp what you want our of stereo sources still.

    I don't think this AVR will give you what you want out of stereo sources.... Maybe use the Multi-Channel inputs and just split the analog stereo signal perhaps???


    I just dunno. Most AVR's have an all Channel Stereo DSP mode which sums to center, and sends left and right to their respective speakers. If it only has stereo, I think your going to have to live with it on two speakers.
     
  6. Matt:Brunmeier

    Matt:Brunmeier Stunt Coordinator

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    see, but I've never heard of a receiver that "just has stereo" (not one that supports 5 channels at least). It also has a Circle Surround mode in DSP for music that plays equally to all channels.

    Still, the fronts are the only ones that play at sufficient volume, the rest are practically silent.
     
  7. Kean-Hock Yeap

    Kean-Hock Yeap Stunt Coordinator

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    Matt, how are your speakers setup in the receiver, i.e. FL-CS-RS, etc.? Also, have you done a calibration on your speaker setup before? Maybe you can bump up the level of your rears?

    Also like John S mentioned, my Pioneer 1014TX only plays a music source equally to all my speakers in the All Channel Stereo (or whatever it is called) mode. And I also own a Sherwood RD-7108, and I have not come across a All Channel Stereo equivalent mode on the 7108.
     
  8. Matt:Brunmeier

    Matt:Brunmeier Stunt Coordinator

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    I have all the speakers at L because I'm not using a subwoofer with the setup. The channel levels appear to only go down from 0 (?) and that's where they're all at (0 isn't off, even the fronts are there)
     
  9. LanceJ

    LanceJ Producer

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    Do all your speakers match?

    And a lot of music just plain won't activate your rear channels or will only create a vague whisper, no matter what their volume level is set at.
     
  10. Matt:Brunmeier

    Matt:Brunmeier Stunt Coordinator

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    All right, a little more testing and I've discovered the following:

    From an analog source like a CD player or iPod (stereo) all channels are powered, but very very quiet. From the radio, all channels are powered and the fronts are fine, but the rear and center channels are very very quiet.

    I have not tried a digital source yet, but it seems to me like this thing is just tanked.

    Yes, all my speakers match.
     
  11. John S

    John S Producer

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    Even though you have not heard of it, I think this AVR won't give you what you want form Stereo sources.
     
  12. dennis_

    dennis_ Extra

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    I have a similar Sherwood unit. To get all of the speakers except for center to work with a stereo source, use the DSP selector and choose "matrix" mode. I utilize that and it seems to work great. Also, I have my speakers set up as "small" and it sounds more full bodied that way, I have no idea why.
     

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