Monitor out seems quieter than mains out

  • Hi all,


    I usually run XLR outs from the main out to a couple or a single of RedSound LG12 cabs. However, some of the guys here mentioned I could use the monitor out and set the output for that to be Master Mono to save having to swap from stereo to mono output on the main outs when I change between my two bands.

    Tonight I tried it for the first time using a TRS to XLR cable. The cab was set to 8 on the volume as usual - but I had to set the monitor output level to -6dB before it got anywhere near decent volume with the band.


    Last time, when using main out and XLR, I could use -20dB with no issue. The only other difference is I’m on 7.1.3 public now, as opposed to 6.0.0 like a couple of weeks ago. All performances are levelled previously.


    Anyone have any ideas? Is it a know thing if using monitor output, or a TRS to XLR cable?

  • A balanced sognal is 6db louder than an unbalanced one. However, I’m not convinced that a TS to XLR cable or adapter like Paul suggested actually creates a balanced signal. I could be wrong though.

    if that’s the case, then the TRS to XLR should have been as loud as the main outs via XLR, surely...? If it’s 6dB louder than unbalanced, then the TS to XLR I just ordered would be even quieter.

  • A true balanced signal doesn’t care what kind of connection is on the end. Two TRS, two CLRor one of each makes no difference. It is the output and input of the equipment being connected that needs to be balanced. The Monitor out is an unbalanced output. Therefore, I don’t think it makes any difference what cable adapters you use you are still sending an unbalanced signal so 6db quieter than a balanced one.


    Using a TRS to XLR from the Main outs should be the same volume as an XLR to XLR from the main outs as the output is balanced in both cases.


    http://www.aviom.com/blog/balanced-vs-unbalanced/

  • Using a TRS to XLR from the Main outs should be the same volume as an XLR to XLR from the main outs as the output is balanced in both cases.

    Actually it's not, Alan:


    All units except for Stage

    Main & Monitor TS - Unbalanced, +16 dBu max

    Main XLR - Balanced, +22 dBu max


    Stage

    Main XLR & TS and Monitor TS are all +15 dBu max.

  • Thanks both. OK, that would explain things; so basically, whichever cable I use from the Monitor Out (be it TS or TRS) doesn't matter; it's still going to be quieter than the Main XLR outs. Hmmm.


    Looks like Direct Out is the same:


    XLR outputs: +10dB
    balanced; max output level 22dBu.


    TS outputs: ¼ inch +4dB
    unbalanced with ground lift. Max output level 22dBu.


    Monitor Out:
    unbalanced, with ground lift. Max output level 16dBu.


    Direct Output/Send: ¼
    inch TS unbalanced, with ground lift. Max output level +16dBu. Low impedance


    Think I'll have to go back to using the LEFT XLR out into the speaker, and just have one set of patches for this band where the delays and mod FX are all mono, and another set for the other band with everything in stereo (so I can use the dual XLR outs). At least then I won't have to change the Main Outs between mono and stereo all the time.

  • Thanks Nicky. You are correct........ as usual ?. I had forgotten that the outputs sent a different level. However, that is configured inside the device rather than the result of balanced Vs unbalanced signals.


    Am I correct in my understanding that simply adding a TS to XLR adapter to the unbalanced Monitor Output won’t suddenly create a second in phase signal to boost the level by approx 6db and equal the level of a balanced source with the same send level?


  • Think I'll have to go back to using the LEFT XLR out into the speaker, and just have one set of patches for this band where the delays and mod FX are all mono, and another set for the other band with everything in stereo (so I can use the dual XLR outs). At least then I won't have to change the Main Outs between mono and stereo all the time.


    Could you not just reduce the level of the main XLR outputs by 6db and leave it there rather than try to boost the other out to match?

  • Could you not just reduce the level of the main XLR outputs by 6db and leave it there rather than try to boost the other out to match?

    Good thinking - I could do, but then it reduces the headroom to increase the volume. Just conscious I was almost at the top end of the range last night, and it was still not quite loud enough.


    I'm now thinking it might just be easier to have both cabs for both bands.... they're backline (and the stereo FX won't be as pronounced in the dual guitar band as they'll both be behind me - as opposed to one either side of the drummer in my other band), but that might save some hassle...!

  • Am I correct in my understanding that simply adding a TS to XLR adapter to the unbalanced Monitor Output won’t suddenly create a second in phase signal to boost the level by approx 6db and equal the level of a balanced source with the same send level?

    I believe so, Brother Alan.


    You can split a signal as many times as you like but recombining the components will never create an increase in strength; that'd be perpetual-motion-machine stuff.