FOH – MON Split // Tie Lines or Direct Out?

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This topic contains 9 replies, has 8 voices, and was last updated by Profile photo of tourtelot tourtelot 2 years, 6 months ago.

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  • #89642
    Profile photo of RancherAUT
    RancherAUT
    Participant

    Hey Guys,

    I know, you had that already – but maybe there is fast help:

    I have the SQ5 as Monitor on Stage and a Dante Card inside for bringing Signals to FOH digitally.
    Because our FOH is not always the same, we have the SQ5 as Master, the stage setup (including) monitoring is always the same.

    Would you prefer splitting the signals via tie lines or direct out?

    TIE LINE = PrePreamp?
    DIRECT OUT = POST PREAMP, before trim? (first possibility)

    Is there a disadvantage for the FOH, if the Monitor (and Master) is sending the signals without going through the preamp? when the receiving mixer (slave) just gets the pure signal, just having TRIM for adjusting, will that affect the sound? badder?
    When using the DIRECT Out (post preamp) and changing GAIN on the Monitor (master) – will that affect the signal level arriving at the FOH (slave)?

    What about your experience?

    THX!

    #89653
    Profile photo of KeithJ A&H
    KeithJ A&H
    Moderator

    Hi Rancher,

    As with your post on virtual soundcheck, there is some confusion here about what happens where in the signal path, so hopefully I can clarify!

    There is a digitally controlled analogue preamp for each XLR socket (whether locally on the SQ or in an expander). This is where the gain, phantom power and pad ‘live’.
    After the preamp, the signal is converted to digital, and can then be sent to the SQ core, where it can be routed around, or assigned to input processing channels (at which point the following digital signal path diagrams come into play – https://support.allen-heath.com/Knowledgebase/Article/View/sq-signal-path).

    So there is no ‘pre-preamp’, the signal has to be brought to line level and converted to digital before you can do anything with it. An expander ‘expands’ the console it is connected to, and the preamps in the expander are therefore controlled by this console. Any sharing of audio after this point is digital, but the signal can still be ‘trimmed’ using the digital trim in processing.

    The SQ has 48 input processing channels, but can have hundreds of input sockets. Tie Lines allow you to patch these input sockets directly to any of the hundreds of possible output sockets, but without passing through any processing.
    Direct Outs on the other hand, are tap-off points from the input processing channels, so send the signal after some or all of the processing (options shown in the linked article).

    Generally for FoH/Mon split, you would use Tie Lines. Hardware gain would be controlled by whichever console the preamps are connected to, and will affect the signal throughout the chain, but should be set correctly for the source and left alone. After which, FoH and Mon consoles can use trim to adjust their signal independently.
    A handy feature in this kind of setup is ‘Preamp On Surface’ in ‘Setup > Surface > Surface Prefs’ as when this is ‘Off’, the preamp control on the surface will always control trim, and it’s more difficult for the console controlling the preamps to make a gain change that would affect everyone! 🙂

    Hope this helps,
    Keith.

    #89693
    Profile photo of RancherAUT
    RancherAUT
    Participant

    Thank you Keith!!
    Much more light in the dark right now!!
    thx!!

    #89702
    Profile photo of airickess
    airickess
    Participant

    Keith, just to clarify –
    In a FOH/MON situation using the Tie Lines feature, once the gain has been set for an input, one can go to the ‘Preamp On Surface’ feature and turn off the control of the preamp level, thus making the Gain pot control simply a trim control?

    #89704
    Profile photo of MarkPAman
    MarkPAman
    Participant

    Yes

    #89705
    Profile photo of KeithJ A&H
    KeithJ A&H
    Moderator

    Hi airickess,

    Exactly, so it’s probably quickest to use the gain pot on the surface for setup. Switch ‘Preamp on Surface’ OFF.
    Then if you did need to make adjustments to gain, you can still go into the preamp section of the processing screen, but the dedicated rotary will control trim.

    Cheers!
    Keith.

    #89841
    Profile photo of Jephsound
    Jephsound
    Participant

    Keith, in looking at this signal flow (thank you) it would shows the insert point being before the channel EQ and compressor. Doesn’t this lower the utility of the Dynamic EQ, which is an insert. Dynamic EQ and Multiband compressors, are dynamic corrective tools, so in effect you are correcting something that hasn’t been set up yet. I may be all wet in my thinking. I’m just trying to figure out the best way to utilize the great tools.

    #103512
    Profile photo of BradM
    BradM
    Participant

    For posterity, I think this might be the article previously linked here:

    SQ. Basic Signal Path Diagrams – Input/Group/LR/Aux/Matrix
    https://support.allen-heath.com/hc/en-gb/articles/4402940459537-SQ-Basic-Signal-Path-Diagrams-Input-Group-LR-Aux-Matrix

    I also had a clarifying question:

    If using ‘Preamp on Surface’ = OFF, Does the input meter still show signal directly after the Preamp, or does it show the signal after Trim for that console?

    #103528
    Profile photo of Hugh
    Hugh
    Participant

    IMO a discussion pertaining to the specific reasons for altering a satisfactory mix that is generated on stage is timely for this thread. Several factors are in play that need to be sorted out;

    1) Most decent custom venue installs, where we work, have in place the requisite room leveling as a FOH starting Point.
    2) Some performers and/or ensembles know exactly the mix they need and do not need or want any additional specific channel manipulation.
    3) The ability to place wedge monitoring at apx. the same distance as the FOH bass bloom and dialing in the appropriate HP filter adjustment
    provides the performers a sonic opportunity to control their own dynamic range. (If it ain’t broke- -why fix it?)
    4) Most venues have XLR I/Os on the stage floor that will carry the desired stage mix to the FOH console with the primary SQ5 LR line level outputs.

    I raise this issue to illustrate the importance of developing the self reliance to understand the capabilities of the gear you own and pursuing a satisfactory mix in your rehearsals. In more than 5 decades of work in the acoustic music world, session ready performers do not want outside personnel manipulating their performance. Clearly this is not the case with much of todays hot back line set ups with a bevy of “more me” performers. It is very important for all of us to understand the difference and be able to develop a protocol that best accommodates our needs.
    Hugh

    #103533
    Profile photo of tourtelot
    tourtelot
    Participant

    Old-man eyes, but is there a hi-res copy of the “SQ. Basic Signal Path Diagrams – Input/Group/LR/Aux/Matrix” diagram around somewhere that I can enlarge onto an 8 1/2×11 page so that I can read it?

    D.

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