{"id":409,"date":"2013-04-28T22:40:08","date_gmt":"2013-04-29T03:40:08","guid":{"rendered":"http:\/\/thechristiangeek.wordpress.com\/?p=409"},"modified":"2013-04-28T22:40:08","modified_gmt":"2013-04-29T03:40:08","slug":"no-gain-much-pain","status":"publish","type":"post","link":"http:\/\/thechristiangeek.net\/wp\/?p=409","title":{"rendered":"No Gain, Much Pain"},"content":{"rendered":"
\"Figure<\/a>

Figure 1<\/p><\/div>\n

By far the most frequent problem I’ve seen when working on a new board is poor gain structure.\u00a0 One of the quickest red flags I see is if I sit down at a mixer and see a lot of channel faders that look like what you see in Figure 1.<\/p>\n

That almost always tells me that the gain structure was set up by moving the fader to nominal (i.e. the 0db mark typically 3\/4 the way up the fader) then bringing up the gain until the volume sounds right.\u00a0 Typically the soundman will get away with this, especially if he is not running a lot of channels.\u00a0 What he may not realize is<\/p>\n

\"Figure<\/a>

Figure 2<\/p><\/div>\n

that he is not getting the best quality of the source signal and<\/i><\/b> he is very likely injecting a great deal of noise into the channel.\u00a0 \u00a0If I see faders scatter about like in Figure 2, I have a much higher level of confidence in how the mixer has been configured.\u00a0 No guarantees, of course, but the odds are in your favor.<\/p>\n

What’s going on in the mixer<\/h3>\n

Why is this?\u00a0 Well, there are two things to consider.\u00a0 First remember that you can think of the signal level as a sort of pressure, for simplicity.\u00a0 Say… water in a pipe.\u00a0 The more water – i.e. signal – you have in that pipe, the more water your valves, baffles etc. have to work on.\u00a0 Conversely, less signal going in means less signal for the board – and any processors. \u00a0\u00a0In other words, you will be sending less signal to the compressor, if you have one on the insert.\u00a0 There will be less signal for the EQ to “bite” into in shaping the sound.\u00a0 Less signal to route to the auxiliary buss for other effects or monitors.\u00a0 And if you increase gain on any of the side processors to make up for it, you will also have more noise coming back into the channel.<\/p>\n

The end result is that you could have less effective compression, over EQ of the signal and extra unwanted noise added to the channel.<\/p>\n

Wait, though!\u00a0 That’s only half the story.<\/h3>\n

You also need to consider a few facts on the design of a mixer.\u00a0 First, all electronic processing will add<\/b> noise to the signal.\u00a0 EQ adds noise, Inserts add noise, effects adds noise.\u00a0 You do not want<\/i> noise added to the signal.\u00a0 Of course, higher quality components and design can reduce the noise added but that gets very expensive very fast.\u00a0 Second, the greatest amount of effort and expense in building the quietest part of the mixer goes into the pre-amp.\u00a0 That’s controlled by the gain knob at the top of the mixer.<\/p>\n

Get that?<\/p>\n

I’ll say it again.\u00a0 Your gain control is the quietest component on your mixer.<\/p>\n

And what is the purpose of the gain control?<\/p>\n

I’ll leave the electronics\/physics out of it and keep it practical.\u00a0 The gain control increases<\/span><\/i> the level of the incoming sound so that the rest of the channel as the greatest amount of signal upon which to operate.<\/p>\n

In other words, but bringing up the signal first through the gain setting, you are providing more signal for the inserts, EQ, effects and whatever else you have interacting with that channel.\u00a0 If they have more signal coming in, then they can give more signal with less added noise coming out.<\/p>\n

Finally, consider this if you are using the gain control to get the primary amplification of the input.\u00a0 When the signal gets through all the processing and down to the fader, you will not only have less noise, but when you bring the output level up with the fader, you will be amplifying more of the sound that you want and less of the noise from the board or processor electronics.\u00a0 All in all, you will have a quieter, cleaner mix.<\/p>\n

Getting there<\/h3>\n

The reasons may have been a bit geeky to follow, but actually doing it is likely much easier than you think.\u00a0 Most quality mixers have a Pre-Fader Listen (PFL) button on the channel strips and the control panel of most digital interfaces have a similar signal meter that you can use to check the input levels of the incoming signal.<\/p>\n

All you need to do is set the PFL or open the control panel for the digital interface.\u00a0 You want the channel on, but the fader down, though some boards may not pass the signal if this is the case.\u00a0 If so, set the fader to 0dB, but know you will most likely have to back it off \u00a0for actual use.<\/p>\n

Make sure any compressors, effects or EQ is off.\u00a0 Also you want probably want to mute the output to the speakers for the initial part.\u00a0 This will decrease the chance of feedback while getting things set up.<\/p>\n

\"Figure<\/a>

Figure 3<\/p><\/div>\n

Have the player\/speaker\/singer play\/speak\/sing at performance levels.\u00a0 If you have the output to speakers or monitor off, you may want to warn them they won’t hear anything.\u00a0 Now bring up the gain up until the meters is hitting 0dB at the louder parts of the performance.\u00a0 This looks like what you see in Figure 3.<\/p>\n

If you don’t have a PFL, you probably have a single LED signal light that shows green or red when it is getting a nominal signal.\u00a0 In this case, bring the gain up until the LED lights, then back off a bit so that it flickers when signal is present.<\/p>\n

You can un-mute the channel, set the stereo assign, bring up the main fader, whatever your particular system requires to get sound out of the PA.\u00a0 Now bring the fader up slowly to get the level you want for that performer on that channel.\u00a0 Don’t expect the fader to be up to that 0dB nominal level, but it does happen.<\/p>\n

Notice the difference?\u00a0 And you haven’t even EQ’d or done any side processing yet.<\/p>\n

Speaking of which, now is the time to set that EQ and side processing.\u00a0 Be careful, because if you haven’t been setting gain this way before, you may find that it takes less to get the desired result.<\/p>\n

Now you can repeat this for each of the other channels you are using.<\/p>\n

Caveats (including digital recording)<\/h3>\n

There are a few caveats that need to be brought up.<\/p>\n

First, trust you ears.\u00a0 Lights and meters will only take you so far.\u00a0 If something really just does not<\/b> sound right, then don’t do it.<\/p>\n

Second, as a rule, once you’ve set the gain, keep the hands off.\u00a0 Any adjustments to the gain will affect everything downsteam of it.\u00a0 That means EQ, effects, monitors; everything.\u00a0 Adjust the levels using your faders.\u00a0 Whether they are the slider, rotary or digital on-screen variety, that is what they are there for.<\/p>\n

\"Figure<\/a>

Figure 4<\/p><\/div>\n

Next, if you have more than just a handful of channels open at any one time<\/i>, you will probably want to back down the gain just a bit (Figure 4).\u00a0 The multiple channels do add together and you really don’t want to have too hot<\/i> a signal.\u00a0 An occasional clip is fine, but constant clipping is not good.\u00a0 Unless you are digital.<\/p>\n

And that is the final caveat.\u00a0 In the digital world you never<\/i><\/b> want to clip.\u00a0 Clipping in a digital environment equates to crackle and\/or no signal.\u00a0 When recording into a digital domain, you don’t need as much input gain at the recording stage<\/span><\/i> as you may think.\u00a0 Let’s use Audacity for an example.\u00a0 Whether I’m going from an external mixer into Audacity or taking a USB mic directly in, the input level\u00a0 I’ve found works best is the range where the signal meter just crosses from green into yellow up to a solid yellow.\u00a0 Generally, I don’t let sound check level ride in the red.\u00a0 That “red zone” is your safety margin to keep you from clipping during the actual recording.<\/p>\n

Also don’t be surprised if the waveform display in Audacity is not a big as you may have seen before.\u00a0 Go back to my first caveat — use your ears and listen.\u00a0 You may be surprised.\u00a0 You may also be pleasantly surprised to find that you have less clipping\/saturation problems in your post-processing if you take this approach.<\/p>\n

Finally, I cannot stress enough the need for you to test.\u00a0 Do not take this article as law.\u00a0 They are guidelines.\u00a0 Though it will likely be an improvement over a poorly configured board, at best, they will get you only<\/i><\/b> close to what you want.\u00a0 Your ears will always have to be your final guide and you will have to experiment to get just the sound you want.<\/p>\n

Good luck and please let me know how this works for you.<\/p>\n

Happy mixing.<\/p>\n","protected":false},"excerpt":{"rendered":"

By far the most frequent problem I’ve seen when working on a new board is poor gain structure.\u00a0 One of the quickest red flags I see is if I sit down at a mixer and see a lot of channel faders that look like what you see in Figure 1. That almost always tells me […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[8],"tags":[41,42,47],"jetpack_featured_media_url":"","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5ymfK-6B","_links":{"self":[{"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=\/wp\/v2\/posts\/409"}],"collection":[{"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=409"}],"version-history":[{"count":0,"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=\/wp\/v2\/posts\/409\/revisions"}],"wp:attachment":[{"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=409"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=409"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/thechristiangeek.net\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}