Posts Tagged ‘#mixingboard’

I spent a lot of time in smaller clubs with crowded stages and audience sizes varying from handfuls to standing room only capacity. The challenges come from each of them and have different resolutions. In some ways, I think the large clubs and outdoor events are the easiest to set up and run sound for. If it is a big stage or large arena, you turn everything up so it is in the main mix or no one will hear it. The smaller clubs you don’t necessarily put a microphone on every instrument. You cannot out-power a guitar player with a stack of cabinets. You might not be able to set up independent or multiple Monitor Mixes (stage mix for performers) and many times you have to share monitors (the cabinets or speakers themselves in this case…) between performers with various needs. Add keyboard player(s) or a horn section and it quickly over burdens the PA or sound system.

Setting up the stage with a few solutions in mind can help in each of these situations. In smaller clubs you might not have many options for the arrangement of musicians on stage. Some restraints may be obvious at first. Some will catch you off guard. Knowing what you are up against though can trigger steps to prevent problems.

These are basic but can avoid a lot of small-headache issues:

Place snake closest to center of stage if that is closest to where instruments/vocalists are positioned. Shorter cables are better if they allow performers needed mobility.

Make sure you know where the AC power outlets are. It is a drag to set everything up and not be able to plug in your power amps. (I also recommend bringing long heavy-duty extension cords for versatility)

Try to plug all stage instruments and PA gear along with the mixing board and external sound gear to the same AC breaker box.

Try to plug all lighting or other powered systems to a separate AC breaker box. (If it does not connect to the mixing board to make noise; plug it into another breaker box)

Use balanced (three wire cables) whenever possible. (I have been caught by 1/4″ audio jacks without locks getting knocked out in the middle of a gig more than once and hate anything that does not lock into position. rant now over)

Keep stage volume as low as possible (this is a couple posts all by itself!)

Consider cross-firing stage instrument amps like guitars and bass – rather than pointing at audience.

Make sure sound board is in the best sounding location and also close enough to the stage to connect snake and all gear – especially if you have to route the snake around the outside of the event area for safety or other reasons.

Cables are the first thing to go wrong even when properly handled and maintained. Bring a lot of SPARES.

Turn all power amps (including ones that are built into the speakers OFF or all the way DOWN when connecting or disconnecting gear. (there are shortcuts and general exception practices we will detail later).

Turn all recording gear OFF or down all the way until all devices and channels are connected and tested.

Make sure speaker cables (Mains and Monitors) are long enough to reach the power amps. I bring two long length sets of speaker cables and two short length sets (no matter how many total speakers I have, I will have two full sets….). If one side of the stage is where the power amps are, I use the short cable and the other one might require the longer cable. Sometimes you need both long cables. If I need a spare, I have two!

Drum risers could need low end cuts and even gates to reduce unwanted tones and resonances.

Color Code anything you can. Cables, Mic stands, Monitors, In-Put Channel labels or External gear/boxes. Make it easy to identify in low light. Green microphone goes with green cable goes to green snake plugs into green channel….. I also add a number to make larger sessions manageable. Vocal green 1, 2, 3…. Drum blue 1, 2, 3….. Brass white 1, 2, 3……

Not rocket science, just some thoughts. But if you get in the habit of considering these and other tips each time before you start hauling in equipment into a new venue, your set-ups will become quick and routine, even if the environment is new. If you keep all your gear in one place there are short cut power-up and power-down sequences I will detail soon.

Most of the connectors used for outputs will be 1/4″ male jacks.  These can be for ‘grounded’ (three-wire) or two-wire cables.  To make this part confusing, the cables can be made or changed with adapters to almost any connector type.  For long distances we prefer grounded or three conductor-wire cables as the third wire is used to take common signals from the other two wires, and ‘dump them to ground’.  Common signals would be interference and noise as the plus and negative wires are carrying the signal from the board.  The result is good signal with low noise introduced.  Guitar and keyboard cables typically go shorter distances and typically have a higher or stronger output signal than a microphone for example.  The cables in the snake will use three wire grounded shielded cables even if they are 1/4″ male connectors.

So we might expect to have an XLR connector for the Main Outs to the Main House power amps, but this is not a guarantee.  If 1/4″ jacks are provided it is recommended to use grounded three wire cables.

Most cables will provide a male connector on one end and a similar but female connector on the other end.  Male connectors are often used to connect to In-Puts and Female connectors are often used to connect to the Out-Put.  The male connector of the microphone cable connects to the mixing board In-Put and on the other end the female connector will connect to the microphone out.  Generally speaking there is little advantage plugging an in to an in or an out to another out.   I like to state the obvious LOL!

The mixing board will give us a Main Left and Right out, and probably a Mono Main Out.  These will be connected to the Main or House power amps.  During an event, the amps are usually turned all the way up and the House volume is ultimately controlled by the Main L-R faders on the mixing board.  This is why it is important to turn the Master Volume Faders on the mixing board all the way down whenever connecting or disconnecting equipment or making dramatic changes.

Depending on the board size and configuration you may also have a 1/4″ Direct-Out for many if not all input channels. (this is REALLY cool for recording and a lot of other creative uses…)   These can be really handy for independent channel recording, triggers, audio effects and alternate mixes to name a few.  Basically connect these to external recorder, processor or triggering gear as needed.  I will give some examples as the series expands to other main topics.  You will also have a number of Sends that are used for a variety of tasks and have different names, but with a few configuration details are for the most part the same thing.  Effect Sends, Monitor Sends, Auxiliary Sends, Sub Sends are splitters; they split the signal – keeping the one going to the House or recorder – and allowing you to send a lot or a little of that signal to the Send of your choice using the Send knob. As in the Monitor amps and House amps, the volume knob will ultimately be used to send the proper signal level to the external (and internal) devices or effects.  If you ‘send’ this to a digital delay, it may also have its own input and out put level knobs.

You may also have a two-track input and/or out put.  This is for playing stereo audio devices and for a straight stereo record out option.  Handy to listen to practice tapes, intermission music, PA system tests and other performance related media.

I don’t mind acknowledging that I am different than a lot of the people I know and hear about.

I am PERFECTLY OK with this.  I know my music and lyrics are not the typical main-stream songs blasted everywhere.  I will not appear on any searches.  Growing up and watching all the Westerns and TV shows, I never – not even once – wanted to be the cowboy or the soldier.  I identified with the ‘good guys’ as most kids do, but to me the cowboys and soldiers were not the only good guys.  I identified more with the American Indians living with nature rather than conquering.

I am not sure what exactly inspired this song when I started it.  I often think about music videos and how that could help explain through images some of the themes in this musical piece.  Possibly the new toys that could make sounds that added less traditional Western culture ideas and more ethnic and international instruments.  I also like contrapuntal rhythms and themes, so you will hear a lot in these pieces.

https://itunes.apple.com/us/album/touch-down/id962542289

I want to give you an idea of perspective on some of the articles I have posted and will continue to post going forward.  This is the first video I have posted and while it is rather BORING, it is so informative at the same time.  I guess I have recorded original tunes since the very late 1960’s.  I recorded everything.  I deleted a lot!  But I recorded everything I could.  I experimented and adjusted and re-did and failed a few more times than I succeeded in the early days to be sure!  I also got into photography and then into video recording.  I practiced the mundane over and over until I got the exposure right, then with video until I could zoom and focus manually.  I joined the photography club in high school and learned to develop and enlarge my own pictures – something I thought was close to magic back in the day!

I shared earlier that I used (and still own!!!) what I think was the first personal computer to come out with built in MIDI ports – The Atari ST!  I used a software program back then to record the MIDI tracks and I could generate SMPTE time code and send a signal from the Atari to sync it up with recording machines (I had the Yamaha 4 track CASSETTE recorder during most of this).  When I talk about old technologies and how we used to record songs (or develop pictures…) It is hard for some to understand the challenges we had and the lo-fi quality of the final mix or product.

I want to use this video as an example of many things I refer to in this blog.  In this video, you will see what I saw when looking at the Atari computer monitor when I was playing or recording tracks.  Keep in mind this is all MIDI equipment available years ago.  The song I posted earlier will now be stripped of all guitars, vocals, effects and additional live sounds you heard on the full mix.  As you watch the video you will hear the sequences being played back live into the VCR input.  I took the monitor video out and connected to video in of the video recorder so this is a straight feed for both.  In the recording software, each “instrument” has a separate track.  Drums are all on one track with additional percussion sounds on different tracks, and as a reminder, each note (as triggered from my DX7 keyboard) represented a different drum/percussion sound coming from a drum machine.  You can hear the metronome from the Atari ticking away in the back ground as it is set to record.  As each track plays you can see the musical notes light up depending on the intensity of the track information.  You can also see the tempo of the song, the names of the tracks and the measures and beats as they click by.

The main piano sound is probably familiar to many of you even if you are quite young. It is the classic Piano Tine sound from the Yamaha DX7 synthesizers.  This video should also give you a sense of quality and resolution available at the time.  It might be difficult to hear the difference in song recording quality today, but we are all familiar with video resolution and HD cameras and large screen TV and computer standards available now.  Just think how this applied to the audio quality back then and then play some really old songs you grew up listening to.   It gives a better appreciation and perspective for some of the classic songs that seem to live forever.

 https://itunes.apple.com/us/album/touch-down/id962542289

For me, sequencing is fun and very versatile.  I am not the kind of keyboard player that can jump in on any song and just start jamming.  I do better if I can take my time and learn, practice, and improve before practicing with a full band.  A lot of this might be from the lack of confidence in the early days, but in reality I find myself a jack of all trades and master of none.  If I had spent more time on any one instrument, I might have gotten pretty good.  Fortunately – or unfortunately, I have always been interested in so many different things that my chops were not the best.  As a percussionist, I was able to hear what I wanted, but did not play drum kits so my feet and hands were always locked in perfect step!  Sequencing gave me the ability to lay down rough performances on the keyboard (and remember I use the keyboard keys to ‘trigger’ the drum sounds, so I am still playing keys).  Once recorded using MIDI – again I am not recording the sounds but the physical action and movements, I could enter the Edit Mode on the sequencer and make corrections to timing, notes, durations etc. until the piece felt good to me. For the drums, the standard practice is to use the Quantizing feature (I can go into this later as well for future posts) to make sure all beats were perfectly ‘on the grid’.  I have used drum machines and sequencers since they first came out.  The sounds are great but too often the result of overusing the quantize feature makes the drum tracks sound mechanical – unmoving – and even impossible for a real drummer.  I preferred to leave a little slop here and there.  I want emotion in my songs, not perfection.

In “Bassics”, I just enjoyed the new sounds I had and played with this Bass Guitar patch and came up with the basic groove.   I like adding textures and unusual percussion/FX sounds to keep the songs flowing and changing.  Available sounds are so much better now, but I still enjoy bringing out these old tunes.

The sound board or audio mixer represents the hub in most audio mixing and mastering functions.  everything connects to the board.  Even the lighting system will use channels in the snake to connect from stage to console.  Things get plugged into and things get plugged out of the mixer as needed.  Today’s mixers are blue tooth USB WiFi fire-wired and light-piped together and will connect to an amazing array of devices.  So far we have focused on what gets plugged to the Inputs of the sound board.  There are a number of connection possibilities for the Outputs as well. We have already discussed some of them earlier, so this can be brief as you already know a lot of this in general.

On most sound boards you have a number of analog-out options.  In earlier discussions we talked about XLR and 1/4″ cables and connectors.  These will continue to be the main ones used for outputs.  On the front or face of most mixing boards you will see a stereo headphone out.  It will usually have its own volume knob and probably a selector to pick the options to Monitor including Stereo Out, Solo, Effects Sends, Effects Returns, Sub or Groups, Auxiliary Returns, and other options.  On the back or the top of the mixing board you will see the panel for Out-put connections in different sections.  There are some rules to determine what type of Audio Cable is used and whether it is a male end or female end and whether it has two connectors or three (or more).

In the early days of mixing boards, microphones and keyboards, it was important which brand you purchased.  If you wanted to get ‘that sound’ you had to have this mixing board channel strip or that particular keyboard.  Later on the computer industry similarly shot through their early days and you had the Macintosh or the Windows PC.  If you were brought up with one you could not be talked into the other.  Most modern equipment from PC’s to Automobiles can do everything.  They all have similar platforms and emulators.  There is style and quality as there always will be, but you can get software mixing programs and microphone/guitar emulator plugins that will make your audio tracks sound like anything you want —-THEY CAN EVEN MAKE YOU SOUND LIKE YOU ARE SINGING IN TUNE!!

So if you like Pepsi, no problem.  Want Coke?  Press this button……  More comfortable using a Mac?  Go for it.

All it takes is cash, a thorough understanding of what all the terms mean and a good idea where all the buttons are?!!?

Enjoy!

I am famous for doing things the easy way and if I can, as cheap as possible.  Now that does not mean forget quality and versatility.  It means I won’t spend money on gadgets that I don’t need.  I try to run as clean a mix as possible, and making sure everyone gets heard.  If they are up there ‘playin it‘, I want the audience to hear it.  In reality, it doesn’t take a lot of gadgets to accomplish those two major things; make it sound good and loud enough for the venue, and put all instruments/vocals/strings/spoons or tambourines, I don’t care what it is….  in the mix.   As a band member, hiring sound guys and their rigs, a number of times after sound check and a few songs of the first set, my microphone was turned down so low, no one could hear me even in-between songs.  I could not get the sound man’s attention, or anyone else’s for that matter because no one could hear me (and as a keyboard player I was usually in the back corner of the stage in the shadows Ha!).  So eventually I just adjusted the microphone stand down toward the floor in front of me.  It is easy to hit the wrong button or turn the wrong knob; happens all the time.

Remember that the sound guy cannot hear what is really happening up on stage.  Sometimes you THINK you can.  But you as the sound engineer should be the first person to know what is going wrong when it does.  Keep an eye on all performers – they will look to you first.  As a performer and studio guy, I could tell when the guitar player broke a string, or if the drum head split and when or if the drummer had too much to drink on his birthday gig.  Things will go wrong but a lot of the time it is the sound guy.  You make an adjustment and grab the wrong knob.  They all look alike in the dark part of the venue or room.  The consequences can be anything from a non-event to a full blown crisis, depending on which knob you grab.  Obviously for the extreme crisis, you will know right away what happened and will probably be able to correct quickly.

It is the slow creepy ones that will get you.  Two songs later something changes on stage and chaos begins.

I suggested we set up the mixing board so the FX Returns are plugged into open channels so you can control their volume with the faders rather than the FX Return knobs.  I always turn the effects down in-between songs.  (you also get EQ and other benefits)  This makes it SOOO much easier to see in the dark clubs. I also use the sub-groups to assign drums, vocals, and other groups of mics their own fader that feeds directly to the Main Out or house out.  If there is a problem with one group, you can quickly test by adjusting that sub-group fader and see if problem goes away.  If not, return it to where it was and go to the next sub-group.  This way you do not have to go through fader after fader searching for a bad signal or feedback loop.   Once you narrow down the offending group, you will have a much better idea what the source is!

I would say most live performances the sound board is mixed to a Mono output.  In smaller rooms or clubs, I loved running in stereo.  I mixed for keyboard progressive bands a lot and the stereo keyboards and samplers consumed the rooms when mixed right.  Not in volume——– The vocals (sometimes three sometimes five in the band) panned as well.  Overkill in a way, but not much work and easy to arrange with equipment versatility.  Most boards have stereo FX that can add lot to the imaging.  But again, that is not the norm.  So you can either set board up in stereo and have the Main Output plugged into the MONO OUT to your system, or you can mix to mono and use one Main fader or the other.  That’s about it.  We have covered the entire mixing board, in its basic format.  Headphone outs, Tape or other inputs, on-board effects, Solo or Audition functions as well as digital features make new sections.

As we continue down the signal path, we get to a new section.  This is separated from the EQ section and generally uses a different color coding for the associated knobs.  The next group is the Aux Sends.  Each send represents an output jack that will go to external audio sources. One example would be the stage monitor mix(s).  If you have two monitors on each end of the stage serving performers, you can use Aux Send 1 going to the left monitor and use Aux Send 2 going to the right monitor.  If performer 1 wants to hear themselves and a little bit of performer 2 in the same monitor, simply send a lot of performer 1’s channel to Aux Send 1 and a little of the performer 2 to the Aux Send 1.  If performer 2 does not want to hear performer 1 in their respective monitor, simply turn up performer 2’s channel Aux Send 2 up a bunch and do not turn up Aux Send 2 on the channel for performer 1.  That was probably harder to say correctly than actually doing it.

Three

You can use Auxiliary Sends to route a signal from any channel to external effects boxes like Digital Delays, Reverbs, and even recording devices in a pinch.  You can use it to trigger light boards that have an Audio Input mode.

These Auxiliary Sends can sometimes be switched from Pre to Post.  Some are fixed either way.  This can also get confusing but if the channel Aux Send is in Pre mode it means Pre-Fader.   The volume faders on each channel will affect the level of the signal that is sent to the House or the Main Out of the mixer and when selected, to the headphone out.  It is a good idea to solo instruments in the headphones to pick or change microphone locations and isolate room noise and other performers.  If the Aux is set to Pre-Fader, it means that the Aux Send levels will be determined before the channel fader has any effect.  Turn the channel volume fader all the way down and you will still have plenty of signal going to the Aux Send.   If the Aux Send is in Post Fader mode, the amount of signal sent to the Aux Send for that channel will be directly affected by the level of the channel volume fader.  Fader off = no Aux Send level.  The number of sends will vary widely.  In this case, more is better!

At this point the example starts a new section.  This will affect the Main Out section.  This is where we can set the stereo Pan position, Mute or un-Mute the channel, and Solo the instrument for gain staging and troubleshooting during a performance.  When running in stereo, general rule is very low frequencies get panned to center.  After that, adjust to performance and venue.  Sometimes the stage sound is very loud, and listeners close to the stage will only be able to hear that performer.  Sometimes the shape of the stage or design of venue will require creative solutions using stereo panning.

This strip includes a pair of colored LED’s for signal strength and Peak warning level indicators.  Occasional red for short periods of time are OK, but better to avoid as long as you have a strong signal otherwise.  After we have set the various knobs correctly and have good signal strength, we can use the channel volume fader to set the level of that channel in the House mix.   Channel Mutes can have different affects.  Some boards Muting a channel will stop that audio source from all outs, and some might allow Aux Send 1 & 2 for monitors.  See manuals for lots of details I cannot cover in these articles.

Other examples below with different lay-outs;

TwoOne

But here is the good news;  we have just learned 75% of the face of the mixing board.  Each channel duplicates what we just went over.  All those knobs are now grouped logically, easily identified explained and we understand what each one is for.  Here on in it is repetition for gain staging and sound check.  Use Pad and 1st Gain Stage to adjust signal strength, add or subtract frequencies using the channel EQ, set amount of Aux Send to monitors and effects and set the stereo field positions as we watch level indicators and set channel volume fader.  Repeat.  Finished!

Next we can go over the benefits of Group Sends and the other 20%

We all try to rationalize situations we are not sure of.   We attempt to explain why things happen – or things that happen to us.  We try to understand the world around us.  When I worked at the instrument music store, I rationalized that I got the job because I was a previous customer and that I could program and understand the new digital MIDI keyboards hitting the market.  Very quickly (months, I believe) I was given my own satellite store to manage.  I opened three more chain stores in a few short years.  In reality, I probably bought more in equipment than I got paid to work there!  Almost kidding, but I understood a lot of the toys and had played with a bunch of them, but to get a room full of toys all day long and then get paid to learn all I could about them, well, I won’t get into religion here but that was heaven on Earth.  I would have done it for free.  And do you know how I rationalized being a SALES MAN? (I am pretty anti-establishment from way back………..) I tried to listen to where the customer was coming from and what they needed.  From there I would teach them what I knew about gear that would help get them to the next level.   Everyone needs to get to the next level.  That is what I am doing today.  It is what you are doing right now.

And sometimes we need to explain to ourselves why.   Why do I need to buy that new toy?  Why do they like me?  Why does the sun always shine where I am?  Why aren’t things working as I planned.  Why don’t they understand me?   What did I do right or wrong?  This has bugged me all my life and I hope it does not get to you.  Working in the music store(s) I sold gear to a lot of bands. Some people were regulars.  Always something needed, some new gear.  One of the bands told me that their sound man was on vacation and they needed someone to run sound for them.  It SEEEEEEMED logical to ask me, I knew about the mixing boards and PA systems.  But I had never run sound before ( truth in advertising alert – – – I did run sound for one other band prior to this but that is a funny story I wanted to share with you later.  So I did it once before  ….. technically  …….) What would you do?  These are good customers and by now good friends too.  If I run sound and really suck, the friendship and the work relationships are out the window.  I let them know I do not have a lot of experience but if they don’t have anyone else I would be glad to help.  They decide to go with me for the vacation gigs.  I run through the checklist a thousand times in my head.  I set the stage and house equipment up methodically, I run through the gain staging like riding a bike, I get the monitors working and run CD audio through the mains to test them.  Time to start.   Big crowd.   Lots of people and friends.  As you can imagine I am rapidly cycling through excitement, concern, confusion, fear, panic, and jazzed up one after the other.  The band starts playing and they are soooooo good I just relax.  I think even I can make these guys sound good!  I was lucky.  From what I remember the event was fine.

Their sound man decided to move onto other things and when he came back from vacation I was asked to take his place.  Again I had to rationalize;  well, they only like me cause I can get them a deal at the store. Well, they like me because I can set up the equipment pretty fast.   Well, it went over well because they are really tight and have great equipment.   You have probably done that a bunch of times as well.  It was hard for me to accept all the way down to the point of knowing that they noticed and appreciated the mix.  Their fans did too but most importantly, so did the band wives!  Never forget the power of the spouse!  So now for the first time, I am involved with a real band.  I am the regular sound guy.  The Band understands the power of the PA, and they determine that the sound guy gets equal cut…… as if he is as important to the overall sound as the individual band members were.  Amazing concept and it worked so well over the years.  I could not rationalize my way out of deserving that one; we worked as a team and the band always sounded great.

All this from knowing how to program a digital keyboard.

Again, there are lots of guidelines about setting EQ.  But don’t let this confuse you early on.  Basically, this is a fancy way to change the tone of the signal.  Knobs that are tied together in brackets work together. One determines the frequency range that will be affected and the other knob determines how much boost or cut will be applied to the selected frequency range.  The first instinct is to turn everything up.  Indeed this is quite natural but wrong.  Test after test, many people will say one sound is better than the other even though the only real difference is the higher or louder volume level.  If you think of boosting the frequency group with the EQ as if it were an amplifier turning the frequency group louder, this will help explain why we needed the extra head room when setting up the gain stage – you are making the signal louder when you add EQ boost.  If everything is set and you boost a channel EQ, you can unintentionally overload the input level on the EX send for example, causing that signal to distort or clip when returning back to the mix.

In this configuration there is a hi frequency group cut/boost knob.  Then there are hi-mid frequency knob tied to a cut/boost knob and below another pair in the Low-mid frequency range.  Underneath that is the low end group cut/boost knob.  In essence, select the amount of cut or boost on the frequency groups (Hi – Lo) to shape sound so it reflects the source signal.

For the paired knobs, select the frequency to be affected and using its pair cut or boost that particular frequency (as opposed to a larger group of frequencies for the Hi-LO knobs).  Keeping in mind sometimes less is really more, rather than try to turn frequencies up or louder to make them sound better, try making them sound bad.  Which frequencies interfere with the shape and tone of the instrument?  Does a certain frequency make a nasty squawking sound when it is a bit louder?  Try cutting that frequency a good amount.  You might be able to turn the channel volume up after cutting signals and keep the level not necessarily louder over-all in the mix but in the correct group or place in the instrument/vocal mix.  Listeners will be able to hear the instrument clearer and more distinctly if it closely resembles the real instrument’s group. So this gets pretty easy.  Like a simple home stereo, turn the top know to clockwise to make the sound brighter by increasing the hi frequency group.   Turn it counter-clockwise if it sounds harsh or brittle in the upper range.  The paired knobs allow you to select specific frequencies within a group (Hi or Mid) and then cut or boost to shape the tone of the source and add flavor or reduce gremlins.

For microphones that will be used by vocalists, this is an area where you can make a lot of difference because the vocalist signal is also being sent to the on-stage monitors.  Sometimes they are really loud.  And when that happens, the monitor is blaring the vocalist’s signal right back into the microphone on stage.  This in turn goes quickly to the monitor and straight at the microphone again.  Soon this will turn into a squeal in the range that is strongest or loudest.  This is the classic example of a ‘feed-back loop‘.

The knee-jerk reaction is to turn the channel volume down or turn the monitor sends down.  The better way is to learn which frequency/frequency group is triggering the loop first.  Use the paired EQ knobs to change the hi-mid or lo-mid frequency responsible for triggering the nasty loop.  Successfully done, slowly turn the volume up a bit.  Slowly increase volume (usually to the monitors, but will apply to the House Mains in some situations) until you start to hear a feed-back loop starting.  Determine which frequency it is and turn it down in the mix. You want as much clear gain as you can to the performers. If you can only turn Monitor Send up to 5, let’s say or you get feedback, the performer might not be able to hear themselves over the amplified instruments and will be forced to scream louder and louder to get heard.  If you pull down the offending frequencies you can turn the same signal to the Monitor Send to maybe 8 or so.  Happy vocalist.