Sound Reinforcment System procedures advice

Posted: Mon May 05, 2008 9:32 am

Hi guys, I'm doing a project at college for my sound reinforcement systems class.

I'm writing out the procedures involved for powering up the system, checking it, then powering down the system.

Here is what i've come up with:

System power up

• Check all faders, knobs and switches are turned down on mixing desk
• Power up FOH mixing desk
• Power up all outboard gear
• Power up recording device
• Check all amp knobs are turned down
• Power up bass head and cabinet
• Power up electric guitar amp
• Power up keyboards
• Power up crossover
• Power up bass amp
• Power up speaker amp
• Power up monitor amp
• Turn all amp knobs fully up
• Turn on mixing desk oscillator
• Check speakers are routed correctly using the mixing desk oscillator to generate pink noise through system
• Check monitors are routed correctly using the mixing desk oscillator to generate pink noise through the system
• Check effects units are routed correctly using the mixing desk oscillator to generate a tone through the system
• Switch off mixing desk oscillator
• Set main output L and R faders to halfway
• Check operation of talkback mic
• Set up each instrument channel on mixing desk ensuring gain knobs are set to 0dB in PFL mode
• Turn L&R button on for each channel
• Set levels of all channel fader as required
• Set up graphic equalizer
• Apply effects to required channels via aux knobs
• Set monitor levels for each monitor mix
• Check operation of recording device

System power down

• Turn down all faders, knobs and switches on mixing desk
• Turn all amp knobs down
• Turn off all amps
• Turn off crossover
Turn off all instruments
• Turn off all outboard gear
• Turn off recording device
• Turn of mixing desk

I'm really just looking to see if what i've written makes sense as a general guide to any system. Also if i've missed anything out.

If giving more info on the actual system would help then let me know and i'll fill in the blanks.

Any feedback will be very appreciated;)

Posted: Mon May 05, 2008 11:17 am

Seems a pretty useful list.
You might want to mention any mics involved in the system other than talkback. I assume vocals are included in this setup...

PS how long has your location been set to Scotland? Good to see another "local" around here Razz

Posted: Mon May 05, 2008 3:10 pm

Hi Codemonkey, cheers for the advise;)

This is just a kind of fault finding procedure that is part of the assesment. I've also got:

Details of the system components
Hook up diagrams of the entire system
Placement plans for stage and FOH mixer
Channel plot
Transport document
Equipment checklist
Cable list
Installation and de-rigging plan

I'm not sure if I should include mics within the process list I posted or not. Could you maybe explain a bit more on what you mean here?

Thanks.

P.S.

I've lived in Scotland all my life m8, nearly 27 years! Born and bread in good auld Bo'ness! Not the greatest town to live in but I can't change my roots! lol

I'm actually looking to move to OZ in the future but for now i'm happy with what I have and having fun learning within this crazy industry.

Where about do you stay/come from?

Posted: Mon May 05, 2008 3:21 pm

I figured mics because most bands have a vocalist or 8, so mics would get mentioned - add them, check they work, check they're not pointing at any monitors...
Everything our Church does though, involves mics so to me, sound reinforcement is adding another 10-30dB to the vocals for people talking (is that formally known as Public Address?) or when the drummer starts up, keeping everyone above him.

Myself, Glasgow, 18 years of it. I don't intend moving anywhere (in the next 5 years at least), but a lot of Scots seem to be moving out to Oz, half the pubs down under probably sell Tennents and Famous Grouse lol.

Posted: Mon May 05, 2008 11:11 pm

Uhhhh... one part you left out... which means whether you have gear to use or not...

First and foremost, check for proper line voltage and phase before plugging a single thing in.

While using an oscillator is nice in theory... but, meh... I don't think so. If I got a 58 at FOH... I'm gonna throw some gain at it and talk my way through line checks and calibration.

Then I'll shove some walk-in music on and do a walk round.

Posted: Tue May 06, 2008 2:24 am

Thanks again for the comments guys.

Madmax: This is just for an excercise so I won't actually be using any gear at all. Is this what you mean by "whether you have the gear or not"?

Could you give me a bit more info on what you were meaning about checking line voltage and phase before plugging a single thing in?

Sorry if this seems a dumb question but I can only go on what I have done at college so please forgive my ignorance if i've picked it up wrongly.

Usually when we set up the equipment at the college, we turn on the oscillator to generate pink noise and push up the left main out fader and physically check that the noise is coming from the left subs and speakers. We then do this for the right sub and speakers. Once this is done we send a tone to the effects units to ensure each one recieves the signal. Once this is complete we will check that the monitors are hooked up correctly via the aux sends which are in Pre Fade mode.

After this we check each mic is working and set the channel gain to 0dB in PFL mode then adjust the channel fader to suit, applying any effects required.

One thing I have forgot to mention in my list is to switch phantom power on for any mic or D.I. box that requires it.

Again, thanks for taking the time to have a read through and give me a few pointers, much appreciated;)

Posted: Tue May 06, 2008 7:08 am

As this is going to be here long after your class will require the exercise, lets be sure we leave something complete...

Since;

Quote:

"Hi guys, I'm doing a project at college for my sound reinforcement systems class.

I'm writing out the procedures involved for powering up the system, checking it, then powering down the system. "

And since this checklist could apply to just about any system...

You want to check your AC mains voltage at the wall socket/camlock breakout/etc... For equipment that uses multiphase power, you want to be sure that the voltage is phased correctly using a phase checker.

If the AC power connectors are damaged, or wired wrong, your gear can go up in smoke, flames, or both.

Like I said... I think it's great that they take you through the "correct" method of checking a system...

However... the real world is a bit different. If you end up on your own or with a small production company, you often are quite on the go and don't have time to pink noise a room. You end up having to fly your EQ in by the seat of your pants. Thus my comment of "gimme' a 58 and some walk-in music."

Now, if you are fortunate enough to work for some of the bigger outfits, you will likely use KEF or one of the other tools to get your rig squared away.

One step does concern me though...
• Turn all amp knobs fully up

If you are responsible for doing the backline gear, are these the amps you are referring too? or are you referring to the PA amps?

I also notice you don't mention anything about checking crossovers or crossover points on load in, but you do on the out...

In the order of things... When I light up a rig, the first thing I do at FOH is flatten the main EQ.

When doing monitors, I'll flatten the EQ's as soon as I uncap the EQ rig.

The way I do things is a bit different on the out...
All faders down, flatten all channels on consoles, phantom power off, pull inserts
Amp volume down
Kill amps/crossovers - unless amps are hot. If they are, I'll clear the deck and let them cool down.
Clear the deck of all mic's/stands/DI's
Kill the instruments and backline power (If muso's aren't already done with this)
Clear the deck of all mic cables
Kill monitor world power - Outboard, then console
Kill FOH power - Outboard, then console

e.g. The power down is exactly backwards of power up... then too, most of the time, all of the outboard is in racks that are centrally powered.

One thing that I do is to take a small notebook with me to each gig. If there is a problem with a piece of gear, I make a quick note and mark the offending gear with a small piece of board tape with date and initials.

Not that there's anything wrong with your list... just a few real world observations by one onery old fart who's been giggin' a few times.

Posted: Tue May 06, 2008 8:44 am

Since this is an educational project I'll add a couple of things. You should always take your notebook and do an on location visit. This is when you arrange for power and check the layout.

When you check the power, make sure you don't just poke your tester in there and call it hot. You need to know whether the voltage holds fairly steady and at what voltage or cycles constantly-one part of what can be dirty power. Now find out how many circuits are in the room or venue and if they are all on the same leg of power. Are there any 30A outlets? After all of this you now know whether to request an independent power drop or a generator.

To go along with this you need to know how many amps your rig takes altogether at maximum usage. Know that an average "household" outlet is rated at 15a and if it is an old circuit probably won't let you pull all of that. Know your job requirements as well. Amping a live band will draw way more power than gently and transparently reinforcing a concert band or orchestra.

Make a rough but fairly detailed sketch of the venue. Blueprint how and where you think the band will set up and where your gear is going and where your power will draw. If your crew is not experienced and time is going to be tight then practice the set up/tear down back at the barn.

--

At the gig:
When you get all of your gear set up, make a sketch of the stage & venue showing each amp/mic/stand/stage box et alia. As a beginning engineer these sketches can help you both with post mortem discussions and as references for similar future gigs. Planning can make your life tons easier-just like your power on/off checklists.

Just some thoughts this morning.

Posted: Wed May 07, 2008 1:56 am

Thanks for the replies, a lot of great info there.

Madmax:

• Turn all amp knobs fully up

Sorry, this was meant to be for the PA amps only, I should have made that clearer.

I also appreciate that how i've listed it may differ from the real world, I would expect it to.

As I mentioned before I can only go by what i've been shown so i'm not familiar with checking the voltage of the mains supply or if it is phased correctly. I fully understand the need for putting it in this post though as there will be others who come on and read it so they should know the correct procedure.

Hopefully now anyone else learning and reading this can pick up a little info on how to check a system correctly.

The list I gave is only a small part of the outcome. I can upload some other information that I have if it's of any use to anyone.

Once again, thanks for the help;)

Posted: Wed May 07, 2008 8:36 am

MadMax wrote:

The way I do things is a bit different on the out...
All faders down, flatten all channels on consoles, phantom power off, pull insertsAmp volume down
Kill amps/crossovers - unless amps are hot. If they are, I'll clear the deck and let them cool down.
Clear the deck of all mic's/stands/DI's
Kill the instruments and backline power (If muso's aren't already done with this)
Clear the deck of all mic cables
Kill monitor world power - Outboard, then console
Kill FOH power - Outboard, then console

Max,

Just wondering about your order?

"Pull inserts" before powering off outboard and amps? Would you not want to leave them plugged in until everything was powered down, and why not?

Same for the mics. Why not just wait until all power is off?

And, lastly, why kill outboard equipment before console, and not console first? Would you also attenuate all the input trims for channels and send/returns, etc., if turning off outboards first, to keep switch-off pops out of the still-active console? Does it even matter?

I've just always waited until all power was off to everything before disconnecting anything. Amps first, console second, outboard third...then start yanking things.

Just wondering. Wink

Kapt.Krunch

Posted: Wed May 07, 2008 10:12 am

It's really an all in one movement for me... After the mains and any groups or VCA's are pulled down, I start at channel one and move straight up the strip; Fader down, flatten the channel EQ, kill phantom, drop trim, pull insert... next channel. When I get to the end, the console is "normaled".

I make sure the main amps are trimmed down and powered off next.

Then I flatten the mains EQ and turn off power on the FX/Outboard rack. Because 90% of the time, the console is plugged into the power on the back of the FX/Outboard rack, the console goes down with the rack. Then I drop the power switch on the console supply.

When it's a crew sized gig, the mon AE kills ALL the amps and then runs his console normaled routine.

As soon as possible, we clear mics and stands from the deck. 90% of the time, mic's are damaged on the out because someone pulls a cable and a stand falls over damaging a mic. So, we get them off the deck ASAP. We leave the cables where they are and just get the mic's safely off the deck and start packing them up.

The whole process takes about 10 minutes on a routine gig. When you've got boxes flying in the air and riggers on the clock, you need to get the boxes on the ground ASAP.

So, it gets orchestrated pretty well... with the first priority to protect the speakers... so all the amps are turned down first and foremost. After that it's run the order...

Make a bit more sense?

Oh yeah... as an aside... we usually run power from a distro. Waiting until the power is off is actually waiting until the speaker facing is on the ground and the motors are packed up and points are coming down. So... it makes no sense to wait to kill power to disconnect things. You save your speakers, then the amps... everything else after that is controlled by faders from Mon Beach or FOH. With them NOT sending any signal, it's safe to remove connections.

Posted: Wed May 07, 2008 6:43 pm

I get it SOOOO easy now I read this.

Our setup at Church is permenantly in, its just faders down, amp off, mics and everything packed up if we're not singing the following Sunday, mixer off, lights off, lock the door and go.

Got a gig in a few weeks though...last time we went there the setup took about an hour Embarassed

and this time, I'm doing something slightly more complicated, but it'll still take less time, because we have less to waste. When you have 90 minutes, you use it. When you have maybe 50 minutes, you drop cables like hell and shout more at people who're in your way.
Anyway, I know what I'm doing now, I know how to EQ stuff properly and the only thing I need to worry about is the size of the table I'm having to cram a laptop/LCD and mixer onto. Murphys law: Equipment will always be bigger than the space it needs to be put.

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