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Best way to split/mult signals?

Discussion in 'Recording' started by kelly644, Oct 23, 2005.

  1. kelly644

    kelly644 Guest

    Does anyone have a suggestion for the best way to mult a signal?

    I need to split 8 channels of audio into 2 each...

    Would a Y cable be OK, or would there be significant signal loss or other detrimental effect?

    Thanks
     
  2. Thomas W. Bethel

    Thomas W. Bethel Well-Known Member

    A lot depends on what the output impedence of the source is versus the input inpedence of the input. Most transistor gear that is professional in nature and that does not use transformers has an output impedence of less than an ohm. Most professional gear has an input impedence of 10K or better. So yes you could use a "Y" cable for the split. Could you be more specific as to the equipment you are trying to use both for the source and for the inputs you are trying to go to? This would make it easier to give you a better answer.
     
  3. kelly644

    kelly644 Guest

    The split is going to happen right after the Mic pres. One half will be going into a computer based multi-track (MOTU), and the other split will be going out to a small 16 trk mixer for heaphone mixes.

    I could do it right before also (Split at the mics), but I dont know which way is better.

    I've assumed that by splitting a signal in 2, you would half the gain and increase the noise floor... but I read somewhere that the gain loss is minimal (6db or less), so I have no idea what to do, or if I should be going the active mult route.

    The reason for this is that cuemix doesnt run properly on non HD MOTU 896s (You only get 1 stereo output with zero latency monitoring). I personally would be extremely annoyed if I had to record in a studio where I heard a delay between myself (?) each time a track went to disk.

    Specific equipment wise, it's probably going to be 8 channels of Digimax LT, and 6 channels of SCA Pres (4 a12s and 2 NV), going to a Yamaha MG mixer and the MOTU interface.

    Thanks

    - kelly
     
  4. Kev

    Kev Well-Known Member

    Thge gear you mention ... SCA, a12s and 2 NV ...
    can probably handle a y cord to feed the line inputs of the MOTU 896s and 16 trk mixer.

    You may have a level balanced problem with the 16 trk mixer
    BUT
    the signal top the recording should be good.
    The 16 trk mixer is just for monitoring and I'm sure the level, balanced and perhaps ground loop can be solved.

    The input impeadance of the MOTU is probably bridging ( I hope) and the 16 trk mixer could be high (10-20K ?)

    All guessing here

    Even if the input impedances are 600 ... the gear you mentioned could hang in there OK.
    It would need to be tested.
     
  5. huub

    huub Guest

    Splitting doesn't halve the gain..you lose a couple of db's..if you split after the micpre (linelevel) you lose less, maybe 1 db or less..
     
  6. Thomas W. Bethel

    Thomas W. Bethel Well-Known Member

    Actually if it a low impedence output and a high impedence input on both devices you will not lose anything. This in audio terms is called "bridging" inputs which mean you are trying to get voltage and not current. The theorm states "maximum current flow is between equal impedences" but you are not needing current flow all you need is enough voltage to operate both pieces of equipment with good levels. For more information you can go to:
    http://www.rane.com/note124.html
     
  7. Kev

    Kev Well-Known Member

    totally dependant on load and drive capability
    If the output driver were an SSM2142 and the two loads were 600 ohm then the loss would be greater than 1dB
     
  8. huub

    huub Guest

    oh, okay..I was saying this based on experience..I know very much utterly nothing about impedance and other electronical phenomenons..
    knowing too much about this makes one a bit autistic I notice in everyday life.. :lol:
     

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