Hi again,

I've heard about a couple of ways of setting up a live mix.

1. Set all channel faders to the zero position; not off, zero db.
Bring each respective channel's signal up to the desired spl using the
gain pot and adjust as the night progresses using said gain pot.

2. With power amps off and, if possible, with main output faders off
take each channel's input up to clipping with gain pot and back off to
just below clipping or to zero db on the meter and then use channel
faders to mix the respective channels for the proper mix.

Which is better? Why?

I can see that technique 2 might get a better signal to noise ratio
but might also be so hot as to encourage feedback.
If technique 1 is the best way to go, then what is the purpose of the
channel faders?

Thanks.
Shawn

In article ,
Shawn wrote:
I've heard about a couple of ways of setting up a live mix.

1. Set all channel faders to the zero position; not off, zero db.
Bring each respective channel's signal up to the desired spl using the
gain pot and adjust as the night progresses using said gain pot.

2. With power amps off and, if possible, with main output faders off
take each channel's input up to clipping with gain pot and back off to
just below clipping or to zero db on the meter and then use channel
faders to mix the respective channels for the proper mix.

Which is better? Why?

Number 1 can be a good way to work if you have to chart a mix and
reset it, or if you have to share a console but you have your own
channels to work with. This is because your mix is simply all faders
at zero, not some complex bunch of settings that could get thrown off
by someone brushing against your faders. So, it might be easier to reset.

If you mix monitors from FOH, you can't be diddling with the preamp
gain much after you get the monitors set, or else you'll drive the
performers crazy. So, you will probably use the faders to trim things
out, and not the preamp knob. Unless of course you have a split
monitor system...

I can see that technique 2 might get a better signal to noise ratio
but might also be so hot as to encourage feedback.

Feedback is only dependent on gain, and the preamp setting is only
part of the equation. I don't think most consoles have enough
headroom to operate using #2, and even those that do sound better when
you don't ask them to handle enormous signal levels. Most Mackies
I've used fall to pieces for example handling large signals, so why go
there...

I find myself doing something closer to #2 most of the time (using
whatever preamp output level seems to work best for the room, not
necessarily 0VU and certainly never anything near clipping).

The reason is that it's easier to mix monitors from the FOH console
this way. Basically, you've trimmed each preamp so that the level
going into the sends are pretty uniform between channels. This lets
you dial in a monitor mix 'by numbers' a lot easier.

Yes, the channel faders then get set to some odd values, but I don't
mind that so much. Actually, having the faders set to odd values
helps me remember which channels are which - I tend not to label the
console (or have time to do it), so it's a nice way to remember which
channels are which. That drives other folks nuts, but what the heck...

I also think having standardized levels makes it easier to use insert
effects too, such as compressors and gates. By having the signals
near a nominal level, the controls on a processor will be pretty
uniform from channel to channel, making it simpler to set up and tweak
a mix.

If technique 1 is the best way to go, then what is the purpose of the
channel faders?

For mixing... ;-)

You don't have to leave them at zero all night, it's just a starting
point.

I think the answer to this whole question depends on what situations
you work in. I tend to work on small clubs sometimes with no
soundcheck, and I frequently mix monitors from the FOH console. So,
my methods are geared toward making that work as well as possible and
as quickly as possible. I like having standardized levels so that
much of the rest of the gear doesn't need to be adjusted much for
every set that goes on stage.

Other folks might be touring with their own console using a split
system, running the same show might after night and for them, you
might as well run the faders at zero since little will change from
night to night. Unpack the console, throw the faders up and your mix
is mostly done.


Regards,

Monte McGuire

In article writes:

I've heard about a couple of ways of setting up a live mix.

1. Set all channel faders to the zero position; not off, zero db.
Bring each respective channel's signal up to the desired spl using the
gain pot and adjust as the night progresses using said gain pot.

2. With power amps off and, if possible, with main output faders off
take each channel's input up to clipping with gain pot and back off to
just below clipping or to zero db on the meter and then use channel
faders to mix the respective channels for the proper mix.

Which is better? Why?

Neither, but #1 is a little better starting point than #2. The reason
is that you shouldn't run anything close to clipping, and if you start
out at clipping and back off a little, you'll clip the input stage for
sure when things get loud.

You should actually start beyond the mixer, at the power amplifier, or
powered speakers if that's what you're using. With the power amplifier
gain all the way down and the mixer master gain at unity, play a CD
into the mixer, set the gain so the output meters (the ones that read
the level that's fed to the power amplifiers) read 0 VU on the peaks.
A modern CD is pretty well limited and compressed so the level will be
pretty stable. Now turn up the power amplifiers until it's just too
loud.

If you can't get it to that level, give up. You don't have enough
amplifier power, your speakers are too inefficient, or they're badly
placed. If you have this situation, you'll be tempted to turn the
volume up to "too loud" with the mixer once the show starts, and
you'll either clip the mixer's output stage, the amplifier's input
stage, or both.

When you have your output gain set, then work on the input. With the
master fader at unity (you can pretty much leave it there unless you
have to turn everythingn down when the music police show up) and the
channel faders a few dB below unity, start bringing up the mic trims
until the mix is pretty loud. Turn up each trim and see how far you
have to go before you see the input clip light on the mixer come on.
That tells you something about the level going into the mixer.

You should have plenty of input headroom since all the channels
combined should still only give you a reading of near 0 VU on the
output meters (since this is what you determined was too loud).

Signal-to-noise ratio really means very little when doing live sound.
All but the worst equipment is adequate. It's much more important to
avoid clipping the mixer inputs, the mixer's bus (this is evident when
you have the faders up, the meters are hitting the pin, and you have
to turn the master down), or clipping the power amplifiers.

If technique 1 is the best way to go, then what is the purpose of the
channel faders?

To adjust the balance of the mix once you get things in the ballpark.
The input trims set the headroom, the faders adjust the mix.



--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

Shawn wrote:

I've heard about a couple of ways of setting up a live mix.

1. Set all channel faders to the zero position; not off, zero db.
Bring each respective channel's signal up to the desired spl using the
gain pot and adjust as the night progresses using said gain pot.

2. With power amps off and, if possible, with main output faders off
take each channel's input up to clipping with gain pot and back off to
just below clipping or to zero db on the meter and then use channel
faders to mix the respective channels for the proper mix.

Which is better? Why?

I would say neither is all that great.

In general, I think you want to go with the first half of #1 but
not the second half. Ultimately, you want the fader to be somewhere
in the middle, maybe closer to the top, when the show's actually
going on. Unless you have very, very predictable performers (which
could happen, I guess...) there are going to be variations in
volume, and you need the freedom to adjust in either direction
without putting yourself in the position where you have to adjust
gain and the fader.

There are two reason for not adjusting the gain, in my experience.
One is that you can screw up the monitor mix if you are doing
both mixes on the same mixer. (Or you could screw up sends
to an bus you are using for effects, same idea.) The other is that,
on every console *I've* used, the fader is looong and easy to
adjust precisely, and the gain is a small knob where a 5 degree
change can equal 5 or 10 dB. Maybe others are more dextrous than
me, but I don't want to monkey around with that during a show too
much because I don't think it'll work out gracefully.

Regarding #2, the reason I wouldn't take this approach is that
when you get the very maximum gain without clipping, two things
happen: (1) Santa Claus, the Easter Bunny, and a number of honest
politicians all show up to congratulate you because just like those
characters, there is no such thing as no clipping in a live
environment. (2) you create a situation where, on an instrument
that is going to be lots lower in the mix than others (say an
acoustic instrument only used on a quiet song) and the top 1/2 or
3/4 of that fader is wasted. You've turned a, say, 4" fader into
a 1" or 2" fader for no reason and what you've gotten in return
is greater likelihood of clipping.

The other reason I don't like #2 is that there is nothing to say
your mixer's channels need to run at anything near clipping.
You could, for all I know, run everything at 20 dB or 30 dB
below clipping all the way through the signal path (except maybe
at the power ams) and still have a show that is way too loud.

Bottom line, in my mind, is that when I set the gain, I'm trying
to achieve four things: (1) I want it low enough so that the
channel doesn't clip, (2) I want it high enough so that I am getting
enough signal coming out of the mixer, (3) I want it low and high
enough so that my fader isn't crammed up or down against either
end of its travel, and (4) I want it low enough so that when I
mix everything together, the bus doesn't clip either. As far
as I know, there is no formula that will tell you the right
settings to get those effects. It depends on the situation.
Heck, it seems to even depend on the individual instruments
and how the channel responds to them.

- Logan

"Shawn" wrote in message
om...
Hi again,

I've heard about a couple of ways of setting up a live mix.

1. Set all channel faders to the zero position; not off, zero db.
Bring each respective channel's signal up to the desired spl using the
gain pot and adjust as the night progresses using said gain pot.

2. With power amps off and, if possible, with main output faders off
take each channel's input up to clipping with gain pot and back off to
just below clipping or to zero db on the meter and then use channel
faders to mix the respective channels for the proper mix.

Which is better? Why?

Neither. You don't want to tweak levels during the show with the gain pot,
because that will also change the monitor mix. And the latter setup gives
you no reference points.

Here's what I do: Set the house master, group masters (if any) and all the
faders to the 0dB point. Turn the monitor master(s) off. During sound check,
establish my house mix with the gain pots. I won't touch them again during
the set. Then turn all the monitor send pots to their reference points and
bring up the monitor master(s). This establishes a monitor mix that's
essentially the same as the house mix. Tweak the monitor mix using the
monitor send pots as requested by the musicians; they probably will want
something different than the house mix, but it's a good starting point. As
the concert goes on, tweak levels in the house using the channel faders;
that 0dB mark is your starting and reference point, to which you can return
if need be.

YMMV, but that works for me.

Peace,
Paul

In article writes:

There are two reason for not adjusting the gain, in my experience.
One is that you can screw up the monitor mix if you are doing
both mixes on the same mixer. (Or you could screw up sends
to an bus you are using for effects, same idea.)

After the initial setting, when all equipment and people are happy,
the reason (the ONLY reason) to change the input gain is when there's
a change on stage that significantly affects the mix - for instance
when a singer moves to a mic that was set for a different singer, a
guest vocalist comes on stage, the acoustic guitarist unplugs his
guitar from his DI and plugs in a mandolin which has a substantially
different output level, etc. In these cases, adjusting the gain at the
front end is the correct thing to do since you want to get back to
more or less normal in all of your signal paths. This takes some
common sense, though. When the band has just played an all-electric
song with the drums pounding, then the lead singer sits down, picks up
a dulcimer, pulls the conga mic over to it, and sings a quiet ballad
solo, of course you'll want to adjust the gain of the mic that's on
the dulcimer.

on every console *I've* used, the fader is looong and easy to
adjust precisely, and the gain is a small knob where a 5 degree
change can equal 5 or 10 dB. Maybe others are more dextrous than
me, but I don't want to monkey around with that during a show too
much because I don't think it'll work out gracefully.

Some consoles are indeed built with a fairly large gain change in the
last 30 degrees or so of the gain trim pot. If you're working with a
console like that, it's a pretty good indication that you're really
pushing the gain structure and that it's not the right console (or the
right mic preamp) for the source. You may have to use a more sensitive
mic, turn up the output level on the keyboard or guitar going into a
DI or line input, or use an outboard mic preamp that has sufficient
gain. Often, though, you just can't do anything about that when it's
show time and you have to live with it. That's when you have to apply
your listening skills and not mix by the knob position.

Bottom line, in my mind, is that when I set the gain, I'm trying
to achieve four things: (1) I want it low enough so that the
channel doesn't clip, (2) I want it high enough so that I am getting
enough signal coming out of the mixer, (3) I want it low and high
enough so that my fader isn't crammed up or down against either
end of its travel, and (4) I want it low enough so that when I
mix everything together, the bus doesn't clip either.

This is exactly right, and part of engineering is achieving the best
balance among those things. This sometimes involves actually moving
knobs during a performance, so you should be ready to do so.



--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo