Problem with surround combo

Discussion in 'Archived Threads 2001-2004' started by RichardMA, Apr 25, 2002.

  1. RichardMA

    RichardMA Second Unit

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    I have a Sony TA-E9000ES DD/DTS processor. I recently

    added a Parasound CSE 6.1 surround "expander." THis is

    essentially "Circle Surround's" processor for extracting

    the matrixed centre surround channel plus 2 ceiling

    channels and some other refinements not on the Circle

    Surround box. Basically, the two outputs from the

    Sony rear channels (L-R) are inputted to the Parasound,

    which then outputs them plus the additional matrixed surround channels to my power amps.

    The problem is this; When I used my Sony alone, the rear

    channel residual noise level is near dead silent. Even with the volume set beyond "THX" levels, the channels

    (all of them) are silent except when signals hit them.

    When the Parasound is engaged(it has a bypass control)

    there is a noticeable, white noise hiss that eminates from

    the surround speakers. The hiss is multi-frequency, akin

    to white noise. This occurs no matter which surround mode

    Pro-Logic, DD, Sony proprietary modes I use. I is NOT volume dependent, either from

    the Parasound volume control for the centre surround channel or from the Sony master volume control. While

    this sound is not heard during surround sound signal inputs,

    it is noticeable during periods when the surrounds are not

    fed information. The unit's S.N. ratio is claimed 70db which is (IMO) high compared to the Sony's in any mode, but not so high that the hiss would be as noticeable as it is.

    So, I was wondering if anyone else has experienced with with "add on" 6th/7th channel boxes like the Circle Surround/Parasound unit? Or, if someone knows how I might

    attenuate the white noise either at line level or speaker

    level?

    Oh, in case anyone is wondering, the unit does indeed present "different" sound information through the centre surround speaker than either the left or right surround so it does work in that sense. I have not tried the "ceiling"

    channels yet.

    Thanks!
     
  2. Wyatt_Y

    Wyatt_Y Stunt Coordinator

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    A S/N of 70db....I would have almost guessed that to be a typo.....since most components are >100db. I have two equalizers that I have swapped between, one has a S/N of 106db, the other is 93db. I can clearly hear some hiss with the 93db unit (albeit fairly close to the speaker).

    There are some variations to the S/N measurement - whether its referenced to full output or an intermediate level.... In any case, 70db is a pretty low (poor) S/N (IMHO) so it wouldn't seem surprising that you are hearing some noise.....

    Wyatt
     
  3. RichardMA

    RichardMA Second Unit

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    No, the 70db is unlikely a typo. Some old Pro-Logic

    gear had this kind of noise ratio.

    -Rich
     

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