Gain Vs Volume?
 

Can somebody please explain this to me as though I was a child. I know there are numerous threads already about this but as Einstein said, if a three year old doesn't understand it, you've made it too complicated...or words to that effect.

If I can get the volume on my mixer, for either guitar or mic to where I'm happy without using any gain is that an issue? Do I only use gain when I can't get enough volume?

Thanks in anticipation.

copy paste error will try again

Yes, this method will work for clean sound (i.e. not the distortion electric guitarists like).

Think of gain as "magnification" and volume as "final level." Gain boosts the signal but also adds distortion and noise (less so in circuits designed to be clean). Level isn't active boosting or cutting, it's usually configured as a simple voltage divider, and so it's the final adjustment you make to get the sound volume you want.

The way these two terms are typically used is this:

Gain is the level of the *incoming* signal. You set this so that the device (interface, amp, what have you) is getting a good level of signal in but not too much so it's clipping or distorting.

Volume is the *outgoing* signal. Once the gain is already set, you can adjust the volume so the level going out of the device (the sound out of the speakers, or the signal going to the next device) is where you want it.

Both need to be set correctly for things to work. If your gain (input) of your mic/instrument is too low, the resulting sound may be noisy when you turn up the volume (output) to hear things at the level you expect. If your gain is too high, you won't need as much volume but the signal might be distorted. Actual gain settings may vary, but in general you should have the gain fairly high (leaving a little extra room just in case) without clipping. That will give you the best incoming signal; then you adjust the volume (output) for the level out of the speakers or for the next device in your chain.

Devices like mixers or interfaces that have gain control will usually have indicators for where you should set the gain level; either a meter or LEDs that flash when the signal is good, or is clipping and you should turn down the gain a bit.

The process to set everything correctly is two-step. 1) Set the output volume to centered or flat, then adjust the incoming gain until you get a good level, as shown on the meters, or go until you see clipping and then turn down a bit. 2) Adjust the output volume as needed.

It can become a bit confusing because the two terms are often used interchangeably or differently for different devices. When you have a chain of devices (e.g. preamp > effects > mixer > amp), volume often is used to refer only to the setting for the final sound you actually hear out loud, and gain might be used to refer to all the in and out levels in between. This is often because devices might not have their own input gain control... the input level is dependent on the device before it, so the output of the previous device might be referred to as the "gain".

Thank you. THAT I do understand!

Thank you for taking the time to post this. The two part process makes sense to me...

These are both different words how loud or how strong a signal is or gets when it goes through a particular part of an amplification system.

"Gain" is usually used to refer to what happens in a circuit designed to make a signal stronger/louder. "Volume" is usually used to refer to how much of a stronger/louder signal is being, we might say, "let out" of such a circuit when it is sent to a speaker.

Things, of course, depend on how a given signal chain is designed, and the words can sometimes be used for different stages in ways that are slippery and inexact and interchangeable.

To answer your question: on a mixer "gain" usually refers to the sensitivity of the mixer's preamps. When you set the gain so that the incoming signal is nice and "loud" on the meter, but with the loudest parts still hitting below the point at which the preamp circuit starts to distort (in the red), you are setting the sensitivity so that the signal from your mic or instrument is making the preamp amplify to its strongest level before distortion. Your "volume" control is an attenuator that controls how much of that signal is sent out of the mixer to the next stage of amplification (usually a power amp or one inside a powered speaker--and that amp will have its own sensitivity control--sometimes called "gain" and sometimes "volume"). The purpose of setting these stages is to make sure that you are amplifying as much signal as you can without also amplifying a lot of noise. With most pieces of modern equipment the noise floor is pretty low, however, so if you don't need to use every ounce of your system's ability to make things louder, you can often get away with, say, low gain settings and high volume settings. It will still be loud enough and clean enough for your purposes.

One more note because it's often the source of some confusion: in electric guitar amps, "gain" is usually used to refer to how much the preamp is actually distorting. It still means the sensitivity of the preamp circuit, but those circuits are designed to distort, so in that application, "gain" just means distortion. When such amps also have "volume" controls that sometimes means how much of the loud signal is getting to the speaker, but it is sometimes actually instead a "gain" (that is, a sensitivity) control on the input of the power amp, which comes before the speaker.

I hope that helps.

Louis

Gain usually controls the amplification of the first stage of the amp/mixer/whatever. It's generally meant to compensate for different levels of inputs, different pickups, different mics, etc. A common practice for a clean sound with something like a mixer that has meters or clip lights is to turn up the gain until you just notice clipping, then back off a bit. With a multi-input mixer, that allows you to adjust all inputs to basically have the same incoming signal. Once you've done that, putting the mixer's faders all at the same level should make everything the same volume (as a starting point)

With a simpler thing, like a guitar amp, gain adjusts the input level so that the signal is its strongest without clipping, which will usually produce the least electronic noise. With electric guitar amps, you can also deliberately raise the gain past the clipping point, thereby overdriving the rest of the amp, producing deliberate distortion.

Volume usually adjusts a later stage, and controls how loud the signal is coming out of the system.

So "gain" controls level coming in, "volume" controls level going out.

Of course not all pieces of gear have both controls, some have more, and manufacturers seem to often go out of their way to label things with different names.

I got distracted while writing this and Doug ^^^ posted a very good post while I was finishing.

You're getting some good responses but..... it can depend on the mixer you are using. If you can post a picture of your mixer it might help. Some manufacturers incorrectly use "gain" as a channel volume level and use "master" as the overall output level of the device. However, volume and gain are not interchangeable and they are not the same.

Simply, gain is the amount of audio signal (input signal) increased by an amplifier. Use your gain to balance your input devices plugged into your mixer (guitars, vocals, keys...) so your input signals are balanced. Volume is the output level after processing. Once you have your signal levels balanced, you can increase, or decrease their relative volume within the mix with your channel volume pots. Finally your output volume, or master volume, controls your output level once your mixer processing is done or... mixed. If you don't get your gain set properly up front, your output mix will get more distorted, for some channels, as your output volume goes up.

Thank you all for taking the time to enlighten me. I think I've got it now. I'll have a play around so I can start hearing better. Appreciate everybody's input.

Think of gain like the sensitivity of the preamp. It controls how much of signal coming in. How much sound will ENTER the system. Then, the volume controls how much of the signal will go out, LEAVING the system. It is basically it.

Thank you Rodrigo, appreciate your reply.

One more thought for context:

Normally the sensitivity of a mixer preamp is set in such a way that a “line level” signal (set of standards for device:device connection and much more than a mic level) would be coming in at an appropriate level if the gain was set to 0dB (all the way down).

An sm58 used up close by a powerful but not shouty singer will usually need 25dB or so of gain (12-1 o’clock on the dial or thereabouts) to match the signal to that ideal for further processing. Other sources need more/less to achieve the same outcome.

I always set gain levels using meters first, then bring faders up to around 0, then set the master output to match the environment. If I’ve got the right system this will be between -10 and +5. Any more than that and I’ve brought the wrong gear or have a major mismatch somewhere in the system.

As you were.

So...Once I set the gain I need to set the volume...then I set the master volume? If that's the case, what do I set the volume to?