Basic questions about my channel strip

Discussion in 'Recording/Live Sound' started by Paleolith54, Jun 13, 2019.

  1. Paleolith54

    Paleolith54 Member

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    [​IMG]

    Actually two of them, both basically about the relationship between the Mic and Line inputs (the top two, sorry the photo is a bit blurry.) No questions about the Insert jack.

    1. If I run a 1/4" TRS input to the Line input, is that delivering the same signal as if I were going into the Mic input with an XLR (all other things being equal, of course.) Stated differently, if a get a certain result going into the Mic input with an XLR, will I get the same result plugging that XLR into an adapter taking it to a 1/4" male TRS then going in through the Line input?

    2. If I want two different vocal mics for myself at two different places on stage: can I take one mic into the board via the Mic input, then the second via the Line input, thereby having two mics in one channel? I realize they will both be equally affected by what I do with the remainder of the channel strip, but I don't think I care: I think if I used two channels, I'd set everything the same anyway. Any unintended consequences from doing this?

    As you might guess, I'm looking at ways to get maximum bang for the buck from my available channels.

    Thanks!
     
  2. andrekp

    andrekp Member

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    Read the manual for that mixer. There is no other answer because the details vary for each one.

    Generally speaking (YMMV), the XLR in probably goes through a preamp, while the TRS does not. Both MAY go through a gain stage of some sort. If you plug in two mics, one to XLR, one to TRS, they will like not not have the same gain into the strip, which you don’t want. Gain/sensitivity should be set at the strip input. You can’t effectively do that with two inputs of differing strength.

    Really, read the manual.
     
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  3. Paleolith54

    Paleolith54 Member

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    Thanks. The manual isn’t particularly helpful; like many, it explains things using terms you need to already know.
     
  4. maydaynyc

    maydaynyc Supporting Member

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    You should post the model of that mixer for a more specific answer, but generally Mic Inputs are expecting Mic level signals like the kind you get from a microphone, and line inputs are expecting line level signals like you would get from a keyboard.

    They are typically not interchangeable, although if you do have game controls for both inputs you can sometimes plug a mic into the TRS or a keyboard into the XLR.

    I would highly recommend not trying to plug two sources into one channel, I don't know exactly what would happen but for sure you can only set one channel for 1 Source. My gut says it's a recipe for noise and bad signal at best, feedback ground loops and shorts at worst.
     
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  5. Billinder33

    Billinder33 Member

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    2 mics = 2 channels.

    Mics require mic inputs, which feed into a preamp, which boost mic signal into a 'line level' signal. The line level input assumes you are already operating at line level.

    I'd guess, if you are plugging a mic into the mic input, and a second mic into the line input, you'd hear a lot of the mic input mic (because it's boosted by the preamp) and barely hear the mic in the line input, because it's bypassing the preamp altogether.

    Thus PRE amp.... You need an amp sitting in between the mic and the line level signal.

    Depending on the mixer, you may be able to assign the mic pre to the line input, but likely not both at the same time.
     
    Last edited: Jun 13, 2019
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  6. Paleolith54

    Paleolith54 Member

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    Other replies always appreciated, but you guys answered my questions. Thanks a lot.
     
  7. andrekp

    andrekp Member

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    A lot of these concepts apply to virtually any mixer. Go get lost down the Google hole for a while. You can learn a lot.

    Also, make sure you check the manufacturer’s site. It has, for some reason, become the norm these days that the detailed manuals tend to only be found there.
     
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  8. Motterpaul

    Motterpaul Tone is in the Ears

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    I doubt the line takes trs at low impedance. It is a single lead and shielded ground. My guess anyway.
     
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