Toshiba Owners

Discussion in 'Archived Threads 2001-2004' started by Barry_R, Feb 6, 2001.

  1. Barry_R

    Barry_R Stunt Coordinator

    Joined:
    Jan 25, 2001
    Messages:
    52
    Likes Received:
    0
    Trophy Points:
    0
    This information pertains to the 55HX70, or any similar sets which use a center speaker channel input. I had been having a problem with video interference coming from the center channel input audio signal. This was especially noticable during high volume/sounds, or periods of stronger signal strength. I e-mailed Toshiba Customer Service and they told me that the center channel input is designed for line-level, or pre-amplified, signals only. I told them I thought this was wrong since: A) The manual clearly shows this connection from an amp/receiver to the center input on the TV ,(thus from the amplified center channel output); and B) the manual indicates to control volume with the amp/receiver, which is not possible if this were a line-level output. Toshiba insisted this should be a pre-amplified input only. This still didn't sound right to me so I contacted two different Toshiba service persons. Both stated that the center channel input is for pre-amplified levels only, and that using amplified signals could damage the internal amp and/or power supply. When I pointed out that the manual states NOTHING about this (and, in fact, shows the exact opposite), they both stated that the manual was wrong.
    Is there anyone with a Toshiba set (or knowledge of) that can confirm or refute this ? I've disconnected the center channel input until I can find out if this is true about Toshiba sets, or just a problem with my set.
     
  2. Bob Dycus

    Bob Dycus Extra

    Joined:
    Aug 12, 2000
    Messages:
    16
    Likes Received:
    0
    Trophy Points:
    0
    I have a CW34X92 which I use as the center channel on my DD5.1 system. The center channel is in fact for pre-amplifier inputs only!
    The amplification is done inside the TV.
     
  3. Roger Clark

    Roger Clark Stunt Coordinator

    Joined:
    Oct 17, 1999
    Messages:
    53
    Likes Received:
    0
    Trophy Points:
    0
    The center channel speaker input on the Toshiba's is indeed for line-level only. If your receiver happens to have a pre-out/main-in loop, you could take the jumper off and route the pre-out for the center channel to the TV (this would include volume control).
    Most people don't use the internal speakers of the TV for center channel reproduction since they are inferior in sound to nearly any speaker system you will use and you should try to match the center to the mains (same brand, tweeter type, etc.).
    ================================================== =
    "B) the manual indicates to control volume with the amp/receiver, which is not possible if this were a line-level output."
    ================================================== =
    This is not true, line level pre-amp outputs will be volume controlled (that's how you can use external amps with receivers that have pre-amp outputs, the receiver controls the volume). You are thinking of line-level outputs such as tape monitor out or CDR out, these are not volume controlled and would be equivalent to full volume.
    Roger
     
  4. Mark Zimmer

    Mark Zimmer Producer

    Joined:
    Jun 30, 1997
    Messages:
    4,301
    Likes Received:
    43
    Trophy Points:
    1,610
    When I first got my Tosh, I tried the center channel thing and got the same interference with loud sounds. I discovered that, doofus that I am, I had the wiring backwards. You might try reversing the polarity on one end and see if that helps.
    I stopped using it, however, because it was impossible to calibrate the center speaker to match with my mains. When I ran a 75 dB test signal from VE to the mains, even after reducing the level all the way on the amp I ended up with 88 dB minimum coming from the center. I made inquiry with Toshiba and they said that there's nothing to be done about it. I don't know why they have the center speaker option, because it's completely useless if you're going to run the line from the amp, as it shows in the manual. That would make the preamp only explanation quite plausible, I think. So it's back to the separate center speaker for me.
     
  5. Scott Merryfield

    Scott Merryfield Executive Producer

    Joined:
    Dec 16, 1998
    Messages:
    12,739
    Likes Received:
    1,338
    Trophy Points:
    9,110
    Location:
    Michigan
    As others have stated, the center speaker input needs to be fed by the center channel pre-amp output from your receiver (not the speaker level center channel). If your receiver does not have pre-outs, you cannot use this feature on the Toshiba set.
    If you do not have a dedicated center speaker, I think you would be much better off setting your receiver in "phantom center" mode, which simulates a center channel from your main speakers. The internal speakers in the Toshiba (or almost any other TV) are of very poor quality and will most like not even come close to being a timbre match to your main speakers.
    ------------------
    My DVD Collection
    AFI 100 Films to watch: 40 -> 18
     
  6. Barry_R

    Barry_R Stunt Coordinator

    Joined:
    Jan 25, 2001
    Messages:
    52
    Likes Received:
    0
    Trophy Points:
    0
    Thanks to everyone for the replies. My big concern was that maybe this was supposed to work, but that there was something wrong with my set. Roger, you are right, I was thinking of straight, line-level outputs, not volume controlled pre-amp outs. (Of course, the Toshiba tech got it wrong too, but that's a different story). Your answers, and Toshiba's, would explain the interference problems with this signal. As I said, I'm using my JBL center, which I had planned on doing and provides better sound anyway. I was just curious if it actually worked, or was a worthless feature.
    What doesn't seem right to me, then, is the info in Toshiba's manual. Isn't this something that could cause some damage if the proper input isn't used ? Yet if you follow the manual and connect the center channel out, which is what I did with the connections from my Dolby Pro Logic system, you'd be sending an amplified signal into this input. The manual doesn't say that this should be a pre-amped input, I wonder how many people are using it like that ???
    I Love Toshiba sets, this is my 4th one. But someone sure dropped the ball on that one. Thanks again.
     
  7. Roger Clark

    Roger Clark Stunt Coordinator

    Joined:
    Oct 17, 1999
    Messages:
    53
    Likes Received:
    0
    Trophy Points:
    0
    Just for grins, would you mind quoting the manual?
    Roger
     
  8. Don Beverly

    Don Beverly Extra

    Joined:
    Jun 27, 1999
    Messages:
    24
    Likes Received:
    0
    Trophy Points:
    0
    Yea, well, they also set the contrast at a 100 percent from the factory and don't tell anybody, go figure.
     

Share This Page