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Smart CS-3X, Jr. question

503 Views 2 Replies 2 Participants Last post by  Oscar Neundorfer
Attention CS-3X, Jr Owners:

I note that the back-panel for this unit has two output jacks labeled "SP1" and "SP2". As per Page 4 of the owner's manual, these outputs are for "special future formats such as overhead surround channels and are not used at present". However, these outputs do presently provide the "left minus right" component of the input signal, in stereo as per the Circle Surround matrix (see page 7 of the owners manual).

Any ideas as to how these out-of-phase-signal channels might presently be deployed in an Ex set-up?
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dear ryanm:

Thanx for your response. What I really wonder about is how possibly now to use these extra channels with un-encoded material; ie: a regular un-encoded stereo source. Whadda you think? How can these outputs be used as I state while we wait for arrival of the encoded sources?

[This message has been edited by jsrstereo (edited February 09, 2000).]
A similar question came up in the last few days on the SMART bulletin board. Here is the question and my answer. It was posted by David Cervera:


The question:

: I have some questions about the extra "special" outputs on the CS-3X, Jr. unit. If the unit can be used as a Circle Surround processor, and the special outputs are used to connect to the surround channels, then aren't the special outputs for the out-of-phase signals in the left and right input?

: If that is the case, then when used as an EX decoder, any out-of-phase information in the rear channels will go to the special outputs. If those sounds are going to the special outputs, then those sounds wouldn't be heard in the rear channels at all, unless you have speakers connected to the special outputs of the CS-3X unit. Am I right?

: I know that out-of-phase sounds are not intentional now in the rear surround channels by the sound designers and mixers, but I'm talking about the naturally occuring out-of-phase sounds. If these sounds go to the special outputs, how are those sounds going to be heard if the unit is sending these sounds to the special outputs and the typical EX listener will not have anything connected to the special outputs.


My answer:

Hi David,

Thanks for some very insightful questions. I hope I can answer them to your satisfaction.

You are correct about the SP1 and SP2 outputs being the same as the surround outputs of a standard matrix. And yes, the out-of-phase signals would normally appear there and not in the other outputs (at least within the separation limits of the Circle Surround matrix). HOWEVER, in order for these sounds to appear in the SP1 and SP2 outputs, there must be a well-defined phase and level relationship between the two input signals. This is something that would more realistically occur with intention, that is, the sound mixer would intentionally be placing these signals in the mix to appear at the SP1 and SP2 outputs. This would not be nearly so likely in naturally occuring phenomena.

Also, please bear in mind that to the best of my knowledge this is the way that all ex format decoders operate, so in that sense there is essentially no difference between the SMART product and others on the market.

If this is still a concern to you, then by all means feel free to connect more amps and speakers to the SP1 and SP2 outputs and experiment with the setup to see what results you get. It could be interesting.


I hope this helps.

Best regards,


Oscar Neundorfer

Chief Engineer

SMART Devices, Inc.

[email protected]
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