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Mixers/Consoles Help with feed back

Discussion in 'Sound, Music, and Intercom' started by Crisp image, Jul 6, 2019.

  1. Crisp image

    Crisp image Well-Known Member

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    Hi All,
    Beginner question.
    I recently was working along side an audio guy and he had a small problem of one monitor feeding back when a female performer got near it.
    Now here is my list of fixes in no particular order. What would you do?
    1. Cut the mic level to the monitor
    2. EQ the frequency out (low frequency) of the monitor
    3. EQ the freqnency out of the mic. (female performer and feedback was a low rumble frequency guessing 100-300htz)

    My thought is that the easiest thing to do is cut the level in the monitor which she does not here herself in them. Unless she wants to hear herself then it is not a problem.

    Anyway now it is up to you to educate me a little more with your opinions and vast knowledge.

    Thanks for taking the time to read and respond.

    Regards
    Geoff
     
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  2. RonHebbard

    RonHebbard Well-Known Member Premium Member

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    @Crisp image While we're waiting for others to post, I'm looking at it the following ways:
    I wouldn't reduce the level of the monitor assuming more than your lady performer's in it and others may be counting on the monitor to hear keys, rhythm, other vocalists, et al.
    I wouldn't cut the low frequencies out of the monitor for, similarly to option one, others may be counting on hearing other low frequency content from it.
    I WOULD cut the low frequencies below your lady's range from her mic's input channel, assuming she's the only performer using this microphone.
    Let's page @MNicolai and @TimMc while you're waiting.
    Toodleoo!
    Ron Hebbard
     
    Last edited: Jul 7, 2019
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  3. Crisp image

    Crisp image Well-Known Member

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    When I said dropping the level on the monitor I did mean only her level in that monitor.
     
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  4. steine

    steine Member

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    I agree with @RonHebbard on this, cut the low end on her michrphone if she is the only artist using it.

    1 can be done, but then you constant need to fader-jockey her and the risk of pulling her back up too high is present.

    2 could perhaps be done, buty as he mention it will effect the entire mix in that monitor, not only her mic.
     
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  5. TimMc

    TimMc Well-Known Member

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    Presuming this is a musical play.... Why are singers in the monitors at all?
     
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  6. Aaron Becker

    Aaron Becker Well-Known Member

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    What type of microphones? If as Tim suggested above, it's lapel/headworn/earmount/not a handheld - they probably shouldn't be in the monitors unless you have a ton of gain-before-feedback on the system and it's tuned up real nice for that specific purpose. If it's a handheld, get the singer to correctly use the microphone (none of that 18" away stuff) and drop her level in the monitor. If the mics are overheads, should never be in on-stage monitors.
     
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  7. Crisp image

    Crisp image Well-Known Member

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    It was a bitsa program. Some musical numbers, some dialog, some singing. The mic in question was a headset mic (not sure of the brand).


    I suspect the system that has been newly installed has not been fully tuned yet. She was moving all over the stage so I agree she should have not been in the monitors. All the tech was saying "if they had inears........"
    Regards
    Geoff
     
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  8. Lextech

    Lextech Well-Known Member

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    Depends. Might make sense to EQ a wedge if there is more than one open mic on stage. What else is in the monitor? Might EQ the mic channel if it just her. Was the feedback in her vocal range? How loud are we talking, can we just turn the mix down and get away with it. I mix lots of concerts and feedback control is always a at the moment question/decision after the show starts. However, if I am mixing monitors from FOH that will change my thought process differently then a dedicated monitor console. There is no cut and dry answer to a question like this, it all depends on what, where and how you are set up.
     
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  9. macsound

    macsound Well-Known Member

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    My usual EQ style on any speaker with a microphone in front of it is to apply EQ to the speaker, not the microphone. This is mostly monitors and sometimes front fill (in churches and Q&A corporate)

    The reason why I EQ the speaker is because I usually have more accurate EQ abilities on the speaker audio chain than I do on the microphone. If you start chasing feedback with a 4 band PEQ, you'll never be able to apply broad EQ to make the source sound better and you'll runout of EQ bands vs a 31 band EQ on the aux out for the wedge.
    The difficulty comes with certain music styles such as a HPF on a wedge and the performer asking for more bass guitar.

    Overall however - Rolling off the lows on the channel screws your house mix, but the performer is probably ok with a less full mix that's louder than a quieter, more accurate EQ.
     
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  10. TimMc

    TimMc Well-Known Member

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    High passing the performer's microphone to the lowest note she/he/they sing is the best bet, rather than carving up the LF response of the speaker system, whether main or monitor. I've never been in a situation where a well placed notch filter wouldn't help the HPF, also...

    I think most folks would be surprised at how many inputs are band-passed at mixdown in the recording process... get the most usable sonic info to the tracking recording and then make the changes in mix... which is sort of the work flow you're advocating. If we were recording for mixdown later I'd fully agree with you. :D

    For those who remember Ye Olde Analogue Dayz, most consoles had a fixed HPF, usually around 80 Hz. Worthless in most circumstances as 80Hz is too low. I find I high pass most male vocals at around 150Hz, sometimes higher or lower depending on the voice, and with a fairly steep 18 or 24dB/Oct filter. Females typically 240Hz. If they can't sing lower the input has no need of lower response. High pass.

    But in live audio we don't get to remix, we don't get a second chance :(. In theatre, only in exceptional circumstances should performers with head mics, ear sets, lavaliere mics, etc be put in the foldback. Foldback is for what a performer needs to hear for pitch and rhythm cuing. If the singer can't hear self over the orchestra/band/combo then the MUSIC DIRECTOR needs to address that issue, not the Sound Dept.

    I remember when actors did not have microphones and could easily be heard in large auditoriums. Sadly actors are no longer taught the art and science of vocal projection.
     
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  11. RonHebbard

    RonHebbard Well-Known Member Premium Member

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    @TimMc ; not only: "Ye Olde Analogue Dayz", 'Ye Olde Actor Dayz' as well.
    Toodleoo!
    Ron Hebbard
     
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  12. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    Can't remember exactly the joke, but the punchline is something like, "And I dare you to try to put a headworn wireless mic on Ethel Merman."
     
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  13. RonHebbard

    RonHebbard Well-Known Member Premium Member

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    @TimMc ; not only: "Ye Olde Analogue Dayz", '
     
  14. RonHebbard

    RonHebbard Well-Known Member Premium Member

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    @derekleffew Agreed and posting in support: Especially as Google's fairly certain Ethel's present resting place is: Resting place: Shrine of Remembrance Mausoleum, Colorado Springs, Colorado. Purportedly the Colorado Springs Mausoleum's not fond of visitors fitting headworn wireless mics on their residents; regardless of how they're powered. I suspect solar power is definitely a waste of time.
    Toodleoo!
    Ron Hebbard
     
  15. macsound

    macsound Well-Known Member

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    Always doing HPF on vocal microphones is probably one of the most overlooked solutions. Too many times I've listened to a podcast or a presentation at a school, hotel or church and all too often theres a constant low rumble, tons of handling noise and overall lack of intelligibility due to no HPF.

    That being said, I'm still in favor of using channel EQ for shaping the source on that channel and output EQ for solving problems with speakers or other outputs.
    Assistive listening gets distorted with anything below 500Hz? Don't eq every single channel, EQ the feed to the assistive listening.

    Often feedback is also due to a room's resonant frequency and by taking care of those frequencies "permanently" by EQing the speakers, you've solved the problem for everything. Maybe it's only when a synth plays a high G that you get squealing feedback because of a well sized skylight, or when an acoustic guitar plays a D chord with an open low G because of the cavernous under stage storage. Those known room interactive issues should be solved at the speaker EQ or processor level, not every single instrument's input.
     
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  16. blue439

    blue439 Member

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    True, but times have changed. Audiences' expectations of sound quality are higher now that everyone carries a device (their phone) with perfect sound quality on it. An actor yelling on a stage can be heard, but audiences might not find that acceptable now.
     
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  17. teqniqal

    teqniqal Well-Known Member

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    Something that is not being said clearly here is that any EQ'ing you might be doing to reduce feedback between the headset mic(s) and the stage (wedge) monitor(s) should only be done in the mix of that mic to that monitor, not in the over-all system (albeit, the HPF at 150-250 may also apply to the house, but do that as needed for the house mix separately from what is needed for the monitor mix) . If you don't have a separate monitor mix console, then simply parallel the mic to an unused input channel and do what you need to do there relative to the stage monitor(s) without sending that mix to the house or any other sub-mix.
     
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  18. TimMc

    TimMc Well-Known Member

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    Hang on, Mac, I'm not saying to fix every resonance or feedback loop with HPF. Not at all.

    Careful use of HPF *is* tonal shaping, too! It slices, it dices, it crawls on its belly like a reptile... ;)

    My preference is for loudspeaker systems to be "linear" (not to be confused with "flat"). Whatever EQ and time travel is required to achieve that linearity across the mains and all subsystems becomes sacred and is cloistered away. Tonal voicing is done either at the matrix outputs or at the input side of system DSP (think: Lake). Once all this is consistent I still have my channel strip EQ and mix bus parametric EQ available. It's nice to have a few tools left in the shed :D.

    A halo rig mic picking up unneeded LF needs to be dealt with early in the signal chain as it benefits neither FOH nor other mixes and sends. Note I said "benefits", not "fixes." Fixes are, as you point out, best done elsewhere in the signal chain. So if the singer with the halo rig feeds back standing near the fold back, and the frequency is below her singing pitch, the HPF just helped 2 things without compromising anything.

    We're more in agreement than you might think, Mac.
     
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  19. TimMc

    TimMc Well-Known Member

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    In an ideal world, absolutely, and analog split inputs to separate consoles is what we do on music concerts. The rest of the time it's all from FOH and limits to what can be accomplished varies with the system design, console and the operator's knowledge thereof.
     
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  20. TimMc

    TimMc Well-Known Member

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    What is perfect sound quality? Most of what is heard via consumer ear buds has been processed and "mastered" to be played on sketchy buds with poor/nonexistent ear canal seal, with very little dynamic range. However, for those that listen in active environments the lack of dynamics may mean a better listener experience *perception*. What they hear may not bear a significant tonal or dynamic relationship to recording as released by the artist and producer, though. What is perfect sound quality?

    I've noticed a trend to "can you make everything louder than everything else?". The result is a finely honed (or not) audio track with 3dB dynamic range and soup can EQ with a bass boost the size of Texas. I guess some people like. :shock:
     
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