Cable Box to Receiver hookup?

Discussion in 'Archived Threads 2001-2004' started by John DeSantis, Jan 13, 2002.

  1. John DeSantis

    John DeSantis Stunt Coordinator

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    I recently got Digtal Cable. The Cable Box is a Motorola DCT 2000. I use the Stereo RCA Outs from the C.B. to the TV inputs of my Yamaha 2095 in order to get Pro Logic when available. BUT, if I try and record a Program to VHS I only get Pro Logic playback on the analog channels. If I try and record anything from one of the digital channels, the playback will be analog or at least no rear surround at all. I don't get this. I can get Pro Logic from any channel/program that has it but when I record only analog channels are recorded in Pro Logic. It doesn't seem likely that it's a connection problem or I wouldn't get it at all.

    Any Idea? Thanks!
     
  2. Jason Wolters

    Jason Wolters Stunt Coordinator

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    I don't understand the question. Pro-Logic is analog. Can you explain further?
     
  3. Wayne A. Pflughaupt

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    Also, how is the VCR connected to all this (cable-wise)?

    Regards,

    Wayne A. Pflughaupt
     
  4. joe logston

    joe logston Stunt Coordinator

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    the digital stops at the box analog from there on
     
  5. Randy Prue

    Randy Prue Stunt Coordinator

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    John:

    I just went through what you are asking about. I do not know the Motorola, but on my Explorer 2000, I have the following:

    - RF coax (regular "cable" cable with F connectors)

    - RCA line outs

    - S-video out

    - Digital audio coax out.

    Unless I misunderstood the post about "analog after the box" I would like to clarify/disagree. The AC-13 out from the Explorer goes to my AV receiver (giving me switched digital, usually Dolby, through the AVR). It is digital, and it is GREAT!

    The line-outs from the Explorer go to the stereo VCR (which accepts RF/F, and RCA) using the RCA lines, delivering the "best it can" to be taped. The stereo audio contains the matrixed center and surround sounds. The audio out from this also goes to the AVR, so we can watch/listen to tapes.

    The RF from the Explorer is routed through the VCR, then to the television (for watching analog "bypassed" material while taping digital or other analog material), and then audio from the TV to the AVR (so we can listen to analog stereo, which can be PL-II'd or otherwise altered). This uses up three inputs (Video 1 through 3): digital sound from Explorer; analog sound from VCR; analog sound from bypassed material going to TV.

    Does this help you any?
     
  6. Randy Prue

    Randy Prue Stunt Coordinator

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    P.S.

    The S-Video from the Explorer goes through the AVR to S-Video monitor to TV (all video is routed through the AVR, except for the RF bypass, direct to TV).

    The RCA line out from the VCR runs into the AVR too. Now, I'm not sure. It used to not work, but now it does: in on RCA, out on S-Video... something like that.
     
  7. John DeSantis

    John DeSantis Stunt Coordinator

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    The RVA audio outs from the Cable Box go directly to the AVR. Since I can record fine from all analog channels I think my connections are OK. My question is "what is stopping the recording of Pro Logic from the analog channels. These same channels are PLAYED in PL through the AVR but recorded in STEREO onto tape. I don't see what is changing the signal. Just to restate: The AVR Plays ALL channels in PL if available. But when recording to vhs only Analog channels get recorded in PL. Thanks for the responses so far.
     
  8. John DeSantis

    John DeSantis Stunt Coordinator

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    Made a mistake. I meant to say " what is stoping the recording of PL from the digital channels" as I said, just playing them through the AVR gives me PL. And, If the VCR records PL from the analog channels then the connections are OK. At least I don't see anything I should change.
     
  9. John Sully

    John Sully Stunt Coordinator

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    Check your audio setup on the cable box. Choose Menu->Setup->Audio and then choose advanced for "Audio Output". Then select "Matrix Stereo" for "Stereo Output".

    AFAIK, the DCT-2000 downmixes the digital audio to stereo unless this is done.
     
  10. John DeSantis

    John DeSantis Stunt Coordinator

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    John:

    I believe I tried that but I'll go back and check. The thing is I'm getting Pro Logic from ALL channels that I play through the receiver so I'm thinking that setting is OK. It's when I try to tape a Digital channel that PL isn't recorded. It just doesn't make sense. If the receiver is out putting PL and I can tape PL on analog channels, what is changing when recording a Digital channel?
     
  11. Doug_L

    Doug_L Stunt Coordinator

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    John,

    I'm still a little confused after reading everything twice, but here goes:

    How can you be sure that a digital channel, encoded in Dolby Pro Logic, is being recorded in Stereo onto VCR? Likewise, when you record a DPL encoded analog signal to VCR, what makes you so sure that you're getting DPL? I'm not too familiar with the newer model Yamahas, so please help me out on this one.

    You might want to try sending the signal directly from the cable box to the VCR to see if you get the same level signal (ie: stereo or DPL). This wouldn't be a final solution, but a way of testing if the cable box or yor Yamaha is the culprit.

    Also, don't forget that DPL is a 2-channel signal, and is merely encoded in a manner that allows your receiver to decode the 2 channels into 4 (Left, Right, matrixed center and matrixed rear). I mention this b/c your Yamaha may only show 2 channels, but that in and of itself isn't not conclusive that DPL is not present.

    Good luck. I'd like to hear the end of this story.
     
  12. Randy Prue

    Randy Prue Stunt Coordinator

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    John:

    What do you think of this idea? It's a hypothesis that I have not yet tested.

    If you are sending 5.1 digital signals to the receiver, then sending only the front/main/stereo pair signal into the VCR. You (or me, since I want to try this) would have shot yourself in the foot by removing the encoded/matrixed surround from the two main channels, then sending the stereo only (by analog connection) to the VRC.

    Whereas, if you send the matrixed stereo signal into the VCR, it goes onto the tape and can be extracted later by the receiver.

    Could something like this be happening?
     
  13. Wayne A. Pflughaupt

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    John,

    You still haven’t told us how your VCR is connected to all this. Knowing that might solve your problem.

    Regards,

    Wayne A. Pflughaupt
     
  14. John DeSantis

    John DeSantis Stunt Coordinator

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    OK, let me try and answer some of your questions.

    Doug: Yes, I'm sure I'm getting PL through the AVR out to the Speakers. I hear the center and surrounds and It, well, it just sounds like PL. By the way, I'm not using any DSP programs that would simulate PL.

    Randy: I am not sending 5.1 signals to the AVR. This is cable and the best you can get is PL. There are RCA A/V outs on the back of the Cable Box. It says "stereo outputs that can be used to connect to a Receiver" That's what I'm doing and I get Pro Logic sound ( when available ) on ANY channel.

    Wayne: The VCR hookup is as follows. The main coax Cable goes into the CB ( of Course )Then, from CB to VCR IN. From VCR OUT back to CB. The RCA in and outs of the VCR go to the in and outs of the AVR. The Cable Box has a bypass switch which allows you to record Digital channels and watch an Analog channel. It basically unhooks the Box from the TV. At least the Digital Channels, and you go back to using the TV remote to switch channels. The CB stays on the selected channel your recording.

    Also, Randy mentioned or thought I meant 5.1 signals when I say digital. Digital in this case are just the added channels compressed and decompressed by the CB. They are more clear but are only Pro Logic at best.

    I'm thinking this has to do with the Receiver. It's CLEAR that the CB is outputting PL. I can record and play back PL from any Analog channel. ( but not the upper channels ) When I say analog I mean any Channel I had before I got the CB.

    Not sure who suggested this but I think I'll run the RCA outs directly to the VCR LINE IN and see what that records.

    Thanks to all for trying to solve this....
     
  15. Randy Prue

    Randy Prue Stunt Coordinator

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    The way the Explorer 2000 cable decoder says to hook up seems weird, but it works. Where you have the RF cable going into the VCR, then back into the CB... well, the Explorer is configured that way, but the manual says, that to do what you want (bypass, etc.), you short-circuit that by running an RF cable from the CB back to itself (connecting Cable Out to From VCR), both RF females, both on the CB.

    It has a digital audio coax (AC-3) out, which does send 5.1 to the receiver (if it's in the broadcast). It sounds like you don't have this.

    The RCAs go from CB to VCR, then to AVR.

    We get ProLogic from the receiver, if we select it. I don't that ProLogic is actually broadcast. Dolby Digital is broadcast (or not).

    Since you are sending the stereo sound into the receiver, could you be sending back stereo back from the receiver? I think you are because you said the RCAs are a two-way connection to the AVR, whereas my VCR takes its input from the CB, so you are not taking the matrixed sound from the CB. You are sending the matrixed sound into the VCR, and sending back the two front channels only... sounds like you're defeating the matrixed dolby. I'm guessing, but that's what I think would happen. That's why I set mine up the way I did.
     
  16. John Sully

    John Sully Stunt Coordinator

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    I believe that the DCT does not put out matrixed signals on the RF output. You might try hooking up your VCR through the video tape loop on the receiver and record that way. The configuration of the DCT which AT&T uses really is not up to snuff, but that is what we are stuck with.
     
  17. John DeSantis

    John DeSantis Stunt Coordinator

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    I think I'm starting to get a bit overloaded thinking about all the hook-up scenarios. I appreciate all the responses but I still can't get pass the fact that the AVR is playing PL on ALL channels. That HAS to mean that the CB is outputting PL all the time when available. AND, I can record PL on channels 2 to 66. That tells me the VCR connections are OK. How does simply changing the channel to 400 or higher stop the recording of PL even though it's PLAYING through the AVR on those upper channels. This just doesn't seem logical. I know I'm not as sharp at this as most of you because some of your comments have my head spinning. I kind of think that when the VCR sees the signals from one of the upper channels it is some how stoping the PL recording. I need to try a direct input from the RCA outs of the CB to the line in on the VCR. I could even use the front VCR jacks for a quick test. But even if that works then I'll lose the connection to play the TV through the AVR. I may be able to run one of the TV outputs to the AVR though. I had this connection before the I got the CB.

    In looking at some of the possible hookup in the DCT Manual I see that they have the RCA outs going to the VCR even tough it also says you can connect them directly to a stereo. I scanned that diagram and would like to show you but I haven't had any luck trying to get pics uploaded. I'll try again after I close this.
     
  18. John DeSantis

    John DeSantis Stunt Coordinator

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  19. Doug_L

    Doug_L Stunt Coordinator

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    John,
    I know that this is pretty confusing for you - it's confusing for us too!
    Here's something that I didn't want to say before because I though it might send you into overload: Dolby Pro Logic is a 2 channel signal that has been encoded in such a manner from which an appropriate device (ie: receiver/preamp) that can perform Dolby Pro Logic decoding can "create" 4 channels of sound (front L/C/R and rear). To my knowledge, there are no VCR's on the market that can perform DPL decoding - a HiFi VCR can merely pass the 2 channel signal to the decoding device.
    Based on this, I'd have to veto your theory that your VCR is somehow changing the DPL encoded signal into simply a stereo signal.
    It is possible that either the cable box, or the receiver could do this, though.
    Even though your cable box doesn't seem to have a digital output, the signal is digital when it comes into the box. Either every channel carries a full analog audio signal in addition to the digital (where applicable), or the cable box has the ability to convert the digital to analog (which I believe it does). Since you can watch all channels in DPL through the Yamaha, which is only hooked up with RCAs, this "prooves" that the cable box is properly converting the digital signal to 2 channel DPL on the high channels, and sending the DPL encoded signal through the RCA jacks to the Yammie, which is properly decoding the DPL.
    It would seem by process of elimination that the culprit is the RF signal from the cable box. The RF In signal into the VCR should override all other imputs (rca) for a given input source (in other words, even though you've got rca inuts for audio coming from the Yamaha, the audio portion of the RF signal will be what you're hearing). Based on John Sully's belief that the DCT 2000 does not pass the matrixed signals on the RF output, this would seem to be your problem; The audio signal that goes from the cable box to the receiver to the VCR (via rca jacks) is not being heard; the RF signal is overriding it.
    Sounds like you've got too much redundancy. Try using an RCA cable to connect the composite video signal from the cable box to the VCR. This should clear up your problems.
    Hope this works. Keep us posted.
     
  20. Randy Prue

    Randy Prue Stunt Coordinator

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    John:

    Please let me know if you are still sane, or at least able to read.

    I think that a couple of things have become "fuzzy"...

    Dolby Digital can be passed (matrixed) in a stereo signal, whereas Dolby ProLogic is CONSTRUCTED from a stereo source. The ProLogic material does not exist until it is created by the receiver (or other device that contains a ProLogic processor).

    The VCR can record only analog stereo (which may or may not contain the Dolby Digital matrix). The VCR should have a selection (Input Selector). On mine, if I choose CATV, I get the RF signal on the F-terminated cable cable. If I choose Video 1, I get the RCA input from the cable box (because I connected the Video 1 RCA terminals to the cable box). Video 2 gives me whatever I connect to those terminals.

    So, there is no guessing. I know what I am getting because I have to select the input, and I have to route the wires.

    Pro Logic should always be available on any audio you send to your PL-enabled receiver.

    Dolby Digital is only available if it's in the recorded material and if it is passed to the receiver.

    In my system, that means that I am tuned to a broadcast with Dolby Digital encoded/matrixed into the stereo, and that I have sent that (I use coax for the AC-3 (Dolby) output) to the receiver. When this happens, the Dolby Digital light comes on (not the ProLogic light).

    Here's where your set-up might be problematic. If I go stereo from the receiver to the VCR (which I DO NOT DO, but you have done), I may be sending back only two channels (since the receiver "removed" the surround from the matrix and sent it to the surround channels).

    So, the stereo on RCAs from the cable box contains the Dolby Digital matrix, but the stereo on RCAs from the receiver to the VCR PROBABLY does not (I'm speculating, based on logic... haven't tried it yet).
     

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