Does Audio Gain Knob Sound Different Than Attenuation Fader? (Public)

all right today i'm going to talk about gain versus attenuators gain stages versus attenuators so as we deal with pro audio gear semi-pro or any audio gear we run into two basic different ways of controlling the audio level one is a gain stage and the other is an attenuator and they show up interspersed throughout gear it's interesting because on a mixing board typically the very first thing that it runs into will be the gain stage it'll take whatever level and you'll have your gain pot which can boost that level up to a higher voltage higher signal level and then sends it in to the circuitry of the mixing board and the ability to uh drop it down in level and send it various places um throughout the console throughout mixing boards there'll be very gate the various game stages that are fixed that we don't have control over and typically throughout the mixing board we'll have numerous attenuators that we do have control over so it comes in hits the microphone preamp or the gain stage they gain pot he turns it up and that sets the stage that basically spits out a level hopefully uh significantly above the noise floor and below clip and goes to the rest of the electronics then you might have let's say a bunch of og sands you have um and then it goes to your faders and you have whatever else it's going to and then those spit it to the various buses the difference between a gain stage and a fader the gain stage is kind of like the gas pedal on a car it's how much it's how fast the engine's running or how much velocity can get it's it's got the juice then the faders or the attenuators um are they can't go they can't really add juice they can only take whatever the maximum is and send all of it or some of it i'm kind of like riding the clutch or um riding the brake or you know diverting some of the energy elsewhere and so only some of the energy goes to the next uh stage not unlike a pan pot so if you look at a pan pot is kind of an attenuator it is an attenuator that basically if you send it to the center of a pan pot and you send it to the left side my left you're right um all the energy goes to the left and none goes to the right if you just look at as you pan it to the right side the same level is coming in now it sends the energy to the right side and it reduces the volume going to the left well if the right side was just nowhere short of the ground the pan pot would be exactly like an attenuator it basically takes the full signal sensor to the left or some of the signal sending to the left or none of the signals sending to left that's what uh the faders typically do on a console now it gets a little confusing in that the fader will say zero db and maybe it'll have a plus six or plus ten above that zero and the zero db might be three quarters of the way up and then there's a uh the ability to go above that that's actually a little misleading when the faders all the way up what's coming into the fader what's coming into it is what's going out so it's just passing straight through when it has like say a plus six marking on there above the zero what that's saying is that you're turning it down six db the zero is six db below the maximum of what's being sent to it and somewhere else down the line there's a gain stage a fixed gain state of six db bringing it back up to zero such that if it's at zero on the fader it shows up it's actually minus six and then it goes back up and it shows up zero at the end of the line if you put it at plus six then it comes into the fader and it's actually zero but then when it hits that other stage it spits it out at plus six so uh it gets a little confusing there but what's most important to understand is the fader in itself can't distort the signal it just takes all it does is passes it through either all of it or some of it and when i say fade i'm referring to an attenuator the gain stage on the other hand takes and boosts the signal it's an active circuit it has gain it has uh it increases the level and because of that there's going to be a maximum and that's why you'll typically see gain stages have clip lights associated with them and attenuators typically do not because you can't really clip with an attenuator one of the questions i was asked i've been asked quite a few times is coming out of a mixing board into pro power amps where do you set the volumes on the pro power amps and there's a mixed opinion there and that's a great question typically on professional power amps not all of them i've seen some cheaper ramps that have gain pots on the front end but typically on pro power amps those are attenuators and typically those will be marked zero at the full up position and minus however many db as you turn down and you know it's a fader or a attenuator if you see that that means that when they're turned up all the way you're not losing any signal what is sent into the amp passes through that attenuator and at full volume and goes to the gain stage of the amplifier it's interesting the very first thing that happens when we deal with a microphone is it goes into the gain stage of the mixing board and the very last thing that happens it goes into the gain stage of the power amp power amps typically have fixed gain stages we don't have a gain pot control over the amplifier's uh power out it's just a gain it might have 40 db again or 30 db so whatever you put in comes out 40 db hotter into its speaker load then you have an attenuator to fine-tune that so should your attenuators on your amplifiers be all the way up or not uh the answer is depends where do you want your faders to be ideally if everything's pro gear and everything's calibrated your amps will be turned up all the way and your mixing board outputs at 0 db which would send a signal which is right around the point that would clip the amp or pretty close to it and everything would be balanced um if you're doing something where you don't need to have those amps run up in your clip or run full volume it's way too loud for your event running your mixing board with your faders down and your meters not operating at full operating at some portion can be less than desirable you know you can't really see as much you don't have as much indication and you don't have as much room to do stuff so turning your amps down 6 db or 10 db all the way across the board can be a way to bring your faders up on your mixing board as long as you're not really pushing the board hard into clip and causing sonic issues sending distortion to the amplifiers another reason you would want to turn your amps down is if you have grounding issues or rf noise you're in a high noise environment a high electronic noise environment and you're getting buzzes and hums one of the cheats to kind of get rid of that would be to turn your amps down and drive your board hotter and if the noise you're running into is showing up into your cables it's being induced with emf or whatever you will be turning the emf down 10 db at the input of the amp and then turning the signal before up 10 db and you actually get the less noise out of your amp so it's kind of a way to work around it um self-powered speakers now self-powered speakers can come with either an attenuator on the front on the back where the amp is or again it could be either way sometimes there'll be an attenuator and a gain switch or a gain switch and an attenuator a gain pot an attenuator switch or a gain switch and attenuated pot so determining which is which um yeah there's a lot of variables there um as far as your self-powered that's a little trickier or a little different what i would do with self-powered speakers is find out where my console faders need to be what i want to run my metering at and then i would bring the speakers up to get the level that i'm looking for reinforcing with and um use that as my indication um as my reference and so my board is sitting where we want and that's kind of follow us too i guess to both you always want your kind of metering on your board to look correct and then you attenuate or set the gain stages on your self-powered speakers to get you the results you're looking for now i have heard something really interesting about um gain versus uh attenuator or fader and i've actually heard it several times and um i found it fascinating um a couple times two of the time from people that have been doing sound for quite a few years and have a lot of experience so i thought maybe i'd discuss that um it was explained to me that turning up the gain will tend to bring up background noise and other instruments more than the fader which will tend to focus more on the instrument or that you're miking so let's say you have a kick drum here and i set my game pot and it's just below clip or it's just a clip and i set my fader level now i need more a little more level where do i want to get it do i want to get it at the fader or the pot well if i bring up the gain pot it was explained that i'm going to get more background noise but if i bring it up at the fader then i'm going to get more kick and not more background noise we can test that and i'll explain why there's a little bit of truth to it and let's see and why it doesn't make sense as well so i've got my sound bullet here let's fire that up and what i've got is we're going to play we're going to have pink noise come out of this and i've made a special y adapter and this y adapter has one is in polarity um pin two to pin two and the other one is pin two to pin three it's polarity reverse wired so the output of this is being run into this console in polarity in one channel and outer polarity in the other channel and the reason i'm doing that is now we have two equal and opposite signals so i can cancel them out and by and i've got my little micro edge here pico wedge if i bring this up we should hear it and there's some pink noise and there's one there's the other and since these are out of polarity with each other and they're equal and opposite when i bring them both up i can cancel them out so that's both signals being summed together and why that's interesting and cool is because using this method of cancellation with equal and opposite signals i can now demonstrate the difference and the impacts of um gain pot versus um attenuator so right now we've got the game pot set at the same level and the attenuator set at the same level and as you can hear i've got a good amount of cancellation and if i mute one or mute the other and together they cancel out now what happens if i turn the gain pot up really loud and there's clipping you should be able to see that in the overhead camera and i turn it just below clip so now gamepod's really loud and now the other game pod is all the way down i bring that up on the fader and now i'm going to bring this one up it's touchy but adding lots of gain and very little fader or and um or attenuating a lot versus very little gain and a lot less attenuation or a lot more fader allows me to cancel the signal as well and to cancel the signal it has to be dead on i mean it if i touch these height if i touch any of these eq knobs any difference between them will show up as output so it doesn't matter if the game pod is high or low and the fader is higher low the signals cancel out but that's why this um fader brings up the instrument and the game pop brings up the overall that's incorrect except watch what happens if i turn it up to where it's clipping now i will bring this up i'm gonna turn it down a little bit now we're canceling out everything or most things except for the crackling except for the distortion so it actually we can hear this we can hear what's happening when it's distorting the another thing that is happening here is if you run your game pot up really loud it's going to take the loudest thing and it can't reproduce it's going to run into its voltage rail limitations it can't get any louder so it's going to cut the tops off so if you run the gain hot and you're clipping and if you're miking let's say a kick drum well the kick drum is going to be the loudest thing so it's actually going to chop off some of the sound of the kick drum itself it's not going to get the full kick drum it's going to like almost distort compress it so if you bring the gain pot up from there the kick drum is not going to get louder it's going to distort a little bit more and you might not hear the source it might just sound like a little click but it'll bring up all the rest of the stuff around it all the background noise that isn't clipping will seem to get louder whereas if you bring the fader up it's going to take that clipping kick drum or near clipping kick drum and the background noise and bring those up together whereas a gain pot is just going to bring up the background noise if you're into clipping so there is some truth to the fact that if the game pot will tend to rise the background noise but only if you're driving into clip and you're distorting already if you're in the clean um linear section of the game part any i mean this is not an expense it's a cheap behringer console uh even an inexpensive console the gain parts and the faders uh the sound differentials are extremely minor and differential if measurable at all okay game pop versus fader versus attenuator that should do it and i will do another video where i show this stuff in smart and we can look at the frequency response and um talk about some other stuff cool cool awesome so thank you for hanging out and i hope you found this video and others that i do interesting and informative and check out soundtools.com take a look at the products i personally designed some solutions for the pro audio industry uh analog over cat5 a bunch of testers and other useful tools ratsound.com has got our sales department rental department install department we sell a wide variety of pro audio and av gear we do installations small to large and we do rentals for everything as small as local clubs and backyard parties all the way up to coachella festival and artists like pearl jam jack johnson blink182 and thanks for hanging out [Music] hmm

Channel: Dave Rat

Views: 15,961

Rating: 4.9953866 out of 5

Keywords: Dave Rat, Pro Audio, Rat Sound., Mixing Tips, Pro Audio Mixing, Pro Sound, Live Sound, SoundTools, Rat Sound Systems, Audio Engineer, Sound Engineer

Id: chgovyDUxx4

Length: 18min 53sec (1133 seconds)

Published: Sat Jul 17 2021