Best combination of mixer gain, mixer volume, amp/PA volume?

[casualmusic]

Hi all.

I'm new to live sound amplification gear and am interested in knowing how to get consistent results instead of experimental twiddling.

(This is an expanded version of Ohiopicker's question about setting up a dynamic mic and amp).

What sequence do you set the levels of mixer channel gain, mixer volume, and amp/PA volume to get good sound and handy adjustability?

How does the level of each control affect quality and potential feedback?

What sequence is best for handling feedback?

Does it change between using dynamic mics and condenser mics?

In our case, drop-in singers are usually mic shy and we need to crank up the gain of dynamic mics or move to stage condenser mics.

Should guitar (and other instrument) pickups be set at low, medium or high? Should tone be set at the instrument or the mixer?

PS. What is the difference between 'gain' and volume?

Many thanks.

.

[GmanJeff]

Research the term "gain staging".

You'll also want to educate your vocalists about proper mic technique. If they stay further from their mics than they should, they will promote the introduction of unwanted noise into the mics, with many attendant problems. The differences between condenser and dynamic mics typically are simplified to noting that condensers tend to be more feedback-prone while providing higher fidelity than dynamic mics, but those are generalizations and exceptions exist.

[J Patrick]

...lots to cover on this topic...and you are wise to seek advice...I call it gain structure....read up on it by searching gain structure..tons of info available

[YamahaGuy]

For me l, I try to do a practice set up at home prior to any live gig. Then memorize settings.

[Nymuso]

This is what I do. We normally use a small mixer and two Bose L1Cs.

I set the channel gains to zero and the channel volumes to 12 o'clock. I set the L1Cs to 12 o'clock. I set the master volume slider on the mixer to the zero point, which is about 3/4 of the way to max. Now I bring up the channels one at a time using the gain control on each channel and adjust each to what seems to be the appropriate volume.

Now I know I've got the volume and balance I want. During breaks I turn the channel volumes to zero since we have break music coming through the PA via a separate mixer channel. When break is over I know that if I bring the channel vols back to 12 o'clock, everything is the same as where it had been. If, during the course of the gig we must turn up or down slightly, I do this via minor adjustments to the master volume slider on the mixer.

Keep in mind that this addresses volume only, exclusive on any EQ adjustments I might make.

[jseth]

Originally Posted by J Patrick

...lots to cover on this topic...and you are wise to seek advice...I call it gain structure....read up on it by searching gain structure..tons of info available

This... get a basic understanding of the concept and apply it!

You will find that every instrument and mic and line input will require slightly different settings. There is no one setting for everything and no panacea for feedback control, although there are guidelines.

Every room in which you perform will have different characteristics and will need to be compensated for... some may be close but none are the same.

It's a Grand Experiment and an interesting ride... do your due diligence and enjoy the trip!

[RogerPease]

Wow! Good questions, but BIG ones. :-)
What everyone writes is good stuff.
I'll take a whack but I can only wildly generalize answers and there are always and
frequent exceptions.

I appreciate your "top down" approach but it really it might easiest to start with the
specific equipment you're dealing with and the specific setup you're putting together.
Learn the specifics of that and then learn to generalize, if that makes sense.

> What sequence do you set the levels of mixer channel gain, mixer volume, and amp/PA volume to get good sound and handy adjustability?
Start at the source (mic or guitar pickup) and working your way towards the last amp
before the speakers set each level to its undistorted max. Then control the overall
volume from the PA output or master volume.

> How does the level of each control affect quality and potential feedback?
In general you want to keep the output of each stage close to its undistorted max.
This give you highest signal to noise ratio throughout the chain.
The feedback issue is separate.

> What sequence is best for handling feedback?
There's not even a general answer to this. Feedback can come from a lots of different
situations. But first of all keep your overall volume just high enough to get the job done.
There's no need to be "as loud as possible". One thing you can do is set up your entire
rig beforehand, ideally in the same space and deliberately get it to feedback and then
figure out what you can do about it. This is referred to as "ringing out" the PA.

The manual for my Fishman SA330 PA has good instructions for how to go about setting
it up. See if something similar is available for your gear.

> Does it change between using dynamic mics and condenser mics?
Dynamic and condenser mics are very different beasts even though they do similar jobs.
Generally, you'll have a way easier time of it with only dynamic mics on stage.

> In our case, drop-in singers are usually mic shy and we need to crank up the gain of dynamic mics or move to stage condenser mics.
As has been said, teach them good technique. They need to stay close to the mic but not
eat it. Rehearse before hand so you can work with them. Let them see singers with good
technique. My guess is that shy, novice performers get freaked out by the sound of their
voice coming back from the room. They're used to hearing themselves directly. Give them
their own monitor speaker and adjust the level of that so that they hear themselves.

> Should guitar (and other instrument) pickups be set at low, medium or high? Should tone be set at the instrument or the mixer?
See my answers above about setting the level at each stage. Tone can be adjusted anywhere
but if there's a sound tech it's best to let that person do it based on the front of house
sound. Things can sound different on stage in the middle of everything.

> PS. What is the difference between 'gain' and volume?
Gain sets the level coming into an amplifier stage and volume sets the level coming out.
But how things are marked is not 100% standardized. I have an amp whose input level
control is marked "volume" and it's output is marked "master". The concept is the same.

I'm exhausted... Hope this helps. Recap: Learn your particular equipment and setup needs.
Also, read and gain staging and dealing with feedback.

_Roger

[casualmusic]

Hi again.

Your helpful responses let me get a handle on where to start reading and how to get started.

Good thing the reading led to a few online synopsis that are useful right away. And let me tackle those 400+ page textbooks (!) later a few chapters at a time.

Our mic shy singers are only occasional performers. Unlikely they'll develop good mic technique and we will need to adapt the set-up.

Now to experiment with the gear and get good combinations.


Jeff and J:

Thanks for pointing to gain staging and gain structure. A bit of searching and reading helped a lot to understand how to control gain and volume.


Nymuso and Roger:

Thanks for info on how to set the controls instead of random twiddling.


Here's how I plan to start (comments?):

1. Found the mixer zero neutral settings on the channel volume sliders and mixer master volume slider.

Will start with all sliders at zero neutral.

Later during performances will tweak the channel volume sliders for better balance between inputs, and the master volume slider(s) if a bit more/less overall volume is needed.

2. Will set the channel gain for each input device to get sound levels at a highish setting with good balance between inputs, ending up at with each at 70-90 percent of max (and below the clipping and distortion point).

Will set up microphones for mic shy users by testing at the nearest distance (about 10") they like to use.

Will adjust the amp/PA volume up and down as needed
while setting channel gain to get a good overall sound level at 70-90 percent gain.

Will write down the gain settings for each channel/device.

Will attach a number tag ends of XLR/TRS cable to know which input is on which channel (was adjusting the wrong channels at my first session).

Will disregard the compression features at this time.

3. Ringing out the systems for feedback.

I need to do some research. The equipment documentation does not discuss this.

4. Sound check.

Verify each input for level and clarity.

Verify the amp/PA overall sound level.

5. During performance.

Tweak the mixer channel volume sliders if needed for appropriate balance between inputs.

Tweak the mixer master volume slider if needed for a bit more/less overall volume.

During breaks from performance will turn the channel volumes sliders down to zero.

Disregard the various mute buttons to avoid complications at this time.


Many thanks

.

[casualmusic]

Never mind. I kept re-reading the brochure and staring at the mixer until the answers popped out. Thanks.

.