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Title: Fader as compared to main levels
Post by: Dan Crocker on January 16, 2014, 01:43:52 AM
I am a relative newbie to all of this so please forgive the basic questions:

Let's say that I have one mic connected to a console and I set it's fader such that its level peaks at 0db (unity). If I also set my main faders to 0db, will the meters for the mains show a signal level of 0db? If, instead, I then have 10 inputs, all peaking at 0db, what will the main meters show? My understand is that the main meters will show a level that is the sum of all the inputs. But, I don't understand how the math works when the get summed. The question is related to advice I have seen to operate channel faders around 0db. If I manage to do this, don't I need to worry about getting two high a level on the main bus?
Title: Re: Fader as compared to main levels
Post by: David Morison on January 16, 2014, 07:51:11 AM
I am a relative newbie to all of this so please forgive the basic questions:

Let's say that I have one mic connected to a console and I set it's fader such that its level peaks at 0db (unity). If I also set my main faders to 0db, will the meters for the mains show a signal level of 0db? If, instead, I then have 10 inputs, all peaking at 0db, what will the main meters show? My understand is that the main meters will show a level that is the sum of all the inputs. But, I don't understand how the math works when the get summed. The question is related to advice I have seen to operate channel faders around 0db. If I manage to do this, don't I need to worry about getting two high a level on the main bus?

(This may be slightly too basic a question, and answer, for the LAB - you may find the mods move it over to the Lounge shortly).
If you sum two identical signals (ie frequency, phase and amplitude all match), then the sum will be 6dB higher than the individual signals.
If you sum completely different signals each having broadly similar level, then the resultant sum will usually be about 3dB higher, but frequency and phase could vary that a bit.
These would also apply every time you double the number of summed signals eg from 8-16 different signals, you'd expect about 3dB increase.
Many mixers include a reduction in level between the channels and the main bus (or subgroups if included) to prevent overloading the main bus as a result of the summation, so you won't necessarily see that exact amount of gain reflected on the main meters.
HTH,
David.
Title: Re: Fader as compared to main levels
Post by: Steve M Smith on January 16, 2014, 09:46:30 AM
The other thing to consider is that it is better to have your faders around the 0dB position, or about 75% of the way up rather than a lot lower.

If your running position is e.g. only a quarter way up, a small change in position will have a large change in level.  At around the 0dB position it is the other way round.  You need to move the fader more to get the same perceived change in volume so you can be more accurate with your control.

I know that isn't quite what your question was about but it is valid with regards to advice about running around 0dB.

If you find that running everything close to 0dB gives too much volume, you will need to reduce the level on your amps or system processor (or use fewer or lower powered amps!).


Steve.
Title: Re: Fader as compared to main levels
Post by: Tim McCulloch on January 16, 2014, 10:02:22 AM
Dan- please disabuse yourself of the notion of "unity" as it applies to fader position or the level of a signal.  There ain't no such critter, and Mackie's marketing dept should have been shot for giving this marketing effort the patina of science.
Title: Re: Fader as compared to main levels
Post by: TJ (Tom) Cornish on January 16, 2014, 10:06:06 AM
I am a relative newbie to all of this so please forgive the basic questions:

Let's say that I have one mic connected to a console and I set it's fader such that its level peaks at 0db (unity). If I also set my main faders to 0db, will the meters for the mains show a signal level of 0db? If, instead, I then have 10 inputs, all peaking at 0db, what will the main meters show? My understand is that the main meters will show a level that is the sum of all the inputs. But, I don't understand how the math works when the get summed. The question is related to advice I have seen to operate channel faders around 0db. If I manage to do this, don't I need to worry about getting two high a level on the main bus?
Fader position does not necessarily correlate to a signal level., and "0dB" or "unity gain" may or may not mean what you think they mean - as David points out, most consoles factor in summing gain so as to not overload the busses.

The two somewhat interrelated issues are gain structure, and control ergonomics.  Most mixing consoles have a target level for the channel preamp - either 0dB for many analog boards, or possibly some negative number for digital boards - often around -18dBFS.  Nuances aside, what you're trying to do is get the signal level such that it's within the operating band of the console, and that the faders are in a convenient position to mix from.  As Steve points out, fader taper is not necessarily linear, and it's generally easier to mix if your fader levels are around 0dB, because you have more linear motion to work with for small signal changes here than much lower on the fader, where 20dB may only be a fraction of an inch.

My workflow has evolved to the following:
 - I set my preamps such that the signal level is approximately -6dB on the input meter (my board is an A&H GLD).  I find that if I normalize to 0dB, I have less headroom before clipping than I'd like, and since with modern gear there really isn't an issue with noise floor, normalizing to -6dB gives me extra room for dynamic signals with no loss of quality.
- I run my channel faders in the vicinity of -5dB, for a similar reason - more room on the fader to adjust for dynamic signals.
- If with these starting points I've got faders way off my -5dB baseline, I may adjust channel gain, keeping in mind that any adjustments I make after setting up monitors will need to be reversed in all aux sends to keep the relative monitor mix the same.
- I adjust final volume with either the main fader of the console, or amp gain to compensate for running the desk a little cool.

During the show, unless there is a drastic problem, I leave channel gains alone and don't worry about my fader positions too much.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 16, 2014, 01:14:58 PM
Thanks for all the replies. I'll respond here as opposed to each one individually.

David: This was very helpful. You actually addressed one of the things I was confused about. I was worried about overdriving the main bus. I thought that if I operated my channel faders around 0, I'd end up needing a huge amount of headroom on the main bus (3db for every doubling of channels -> 12db for 16 channels). It sounds like maybe I don't need to worry about this if the console automatically attenuates the combined signal from the channels before sending it to the main. In case it helps, the console is the Roland M200i.
One thing that puzzles me is that our previous console (Presonus 16.4.2) seems to behave differently wrt the main fader meter. I didn't spend enough time to correlate the numbers, but Roland's main level seemed to be quite a bit lower than the level for the single channel I was playing with. Meanwhile, the Presonus main level was very similar to the channel's level.

Steve: Actually, this is precisely what started all this thinking. With our previous console, we've been operating channels on the low side and I wanted to change this. I do know that this is where I want to be running. With our new Roland, I want to re-balance things better.

Tim: By unity gain, I guess I mean 0db...no amplification and no attenuation of the signal. I expected these terms to be interchangeable. Marketing BS aside, aren't they the same thing? Don't get me wrong, I'm not saying I like that term or need to use it :).

TJ: Could you clarify your first comment about 0db? What I think it means is that the amplitude of whatever signal comes into the fader section of the circuit is not modified. Of course, there can be all kinds of things before the  fader in question (channel, subgroup, or main) that can modify signal amplitude. Was this your point or was it something else. And yes, I do know that none of this necessarily implies any specific "loudness".
Also, your workflow example is very helpful. A few follow-up questions:
-Once you have your channel faders running around -5db, do you care about what the main fader is set to? I assume you would ideally want it around -5db as well for the same reason you want the channel faders this way. If it ends up being too low (turning it up more would make the mix too loud), it seems like you'd want to to turn down the power amp, right?
-As of right now, the way our church amp is set up, the main fader needs to be turned way down to get the right output volume (or the channel faders end up being low). The M200i has an attenuation setting on the mains. Would adding attenuation with this control be the same as turning down the power amp? Or, is there some downside to doing this?
-For subgroups, I'm assuming I'd want these faders to be set around -5 or 0, right? If so, I'd be inclined to start with all my subgroup faders set to -5db and, more or less, forget about them while adjusting the mix with the channel faders. Then I would use the subgroup faders during mass to play with overall levels for the groups. Does this sound reasonable?

Thanks,
Dan


Title: Re: Fader as compared to main levels
Post by: TJ (Tom) Cornish on January 16, 2014, 01:24:03 PM
Thanks for all the replies. I'll respond here as opposed to each one individually.

David: This was very helpful. You actually addressed one of the things I was confused about. I was worried about overdriving the main bus. I thought that if I operated my channel faders around 0, I'd end up needing a huge amount of headroom on the main bus (3db for every doubling of channels -> 12db for 16 channels). It sounds like maybe I don't need to worry about this if the console automatically attenuates the combined signal from the channels before sending it to the main. In case it helps, the console is the Roland M200i.
One thing that puzzles me is that our previous console (Presonus 16.4.2) seems to behave differently wrt the main fader meter. I didn't spend enough time to correlate the numbers, but Roland's main level seemed to be quite a bit lower than the level for the single channel I was playing with. Meanwhile, the Presonus main level was very similar to the channel's level.

Steve: Actually, this is precisely what started all this thinking. With our previous console, we've been operating channels on the low side and I wanted to change this. I do know that this is where I want to be running. With our new Roland, I want to re-balance things better.

Tim: By unity gain, I guess I mean 0db...no amplification and no attenuation of the signal. I expected these terms to be interchangeable. Marketing BS aside, aren't they the same thing? Don't get me wrong, I'm not saying I like that term or need to use it :).

TJ: Could you clarify your first comment about 0db? What I think it means is that the amplitude of whatever signal comes into the fader section of the circuit is not modified. Of course, there can be all kinds of things before the  fader in question (channel, subgroup, or main) that can modify signal amplitude. Was this your point or was it something else. And yes, I do know that none of this necessarily implies any specific "loudness".
Also, your workflow example is very helpful. A few follow-up questions:
-Once you have your channel faders running around -5db, do you care about what the main fader is set to? I assume you would ideally want it around -5db as well for the same reason you want the channel faders this way. If it ends up being too low (turning it up more would make the mix too loud), it seems like you'd want to to turn down the power amp, right?
-As of right now, the way our church amp is set up, the main fader needs to be turned way down to get the right output volume (or the channel faders end up being low). The M200i has an attenuation setting on the mains. Would adding attenuation with this control be the same as turning down the power amp? Or, is there some downside to doing this?
-For subgroups, I'm assuming I'd want these faders to be set around -5 or 0, right? If so, I'd be inclined to start with all my subgroup faders set to -5db and, more or less, forget about them while adjusting the mix with the channel faders. Then I would use the subgroup faders during mass to play with overall levels for the groups. Does this sound reasonable?

Thanks,
Dan
Dan - kudos for trying to understand all this.

My point about "unity" being a simplification was to take into consideration the various level shifts that happen behind the scenes in the console that you don't need to know or care about, as reasonable boards are going to handle summing without issue.

Modern gear is so good - north of 100dB signal to noise ratio, that you can only really get in trouble through severe clipping - even adding and subtracting 10dB or more at various stages really doesn't make much difference in final quality - unlike 20 years ago.  Everything else comes down to workflow style.

Answering several of your questions at once, I only care about fader position for faders I actually use - I tend to only occasionally touch group faders, and even less often the master fader, so those are less critical.

It is easy to potentially end up with too much system gain, leading to your current situation of having to either run the channel faders pretty low, or the main fader pretty low.  The best solution is probably turning down your amp gain (depending on the type of system - if you have a professionally-tuned DSP, it's probably better to do it on the input level setting inside the DSP rather than change settings on amps which could have side effects to your system tuning), but the attenuation setting on your master section would also work well.

Title: Re: Fader as compared to main levels
Post by: g'bye, Dick Rees on January 16, 2014, 01:25:41 PM
"Unity gain", if it means anything, is the desired optimum level of signal above noise floor THROUGHOUT A SYSTEM.  As such, it proceeds from your pre-amp settings through your channel faders to the summing amps and so on out to the amplifiers and speakers.  So there may or may not be a "unity gain" setting at each point in the chain, but it definitely has nothing to do with numbers, "o'clocks" or physical positioning of any knobs or sliders, simply denoting that the signal is not overly boosted or attenuated at any given stage. 

That's where the term "gain staging" enters in, a better and more comprehensive term which includes the concept of "unity gain".

At least that's the way I think of it...
Title: Re: Fader as compared to main levels
Post by: Steve M Smith on January 16, 2014, 01:30:36 PM
Steve: Actually, this is precisely what started all this thinking. With our previous console, we've been operating channels on the low side and I wanted to change this.

I would much prefer to run the main left and right faders low and keep the channel faders up around 0dB as you are more likely to be adjusting channels than the main output level.


Steve.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 16, 2014, 01:34:35 PM
Thanks.
So, I heretofore will no longer be using this term. It sounds relatively meaningless :)
Dan

"Unity gain", if it means anything, is the desired optimum level of signal above noise floor THROUGHOUT A SYSTEM.  As such, it proceeds from your pre-amp settings through your channel faders to the summing amps and so on out to the amplifiers and speakers.  So there may or may not be a "unity gain" setting at each point in the chain, but it definitely has nothing to do with numbers, "o'clocks" or physical positioning of any knobs or sliders, simply denoting that the signal is not overly boosted or attenuated at any given stage. 

That's where the term "gain staging" enters in, a better and more comprehensive term which includes the concept of "unity gain".

At least that's the way I think of it...
Title: Re: Fader as compared to main levels
Post by: James A. Griffin on January 16, 2014, 01:58:16 PM
Dan- please disabuse yourself of the notion of "unity" as it applies to fader position or the level of a signal.  There ain't no such critter, and Mackie's marketing dept should have been shot for giving this marketing effort the patina of science.

+1   And Peavey jumped on that train, giving the name UNITY to a line of mixers.
Title: Re: Fader as compared to main levels
Post by: g'bye, Dick Rees on January 16, 2014, 02:21:46 PM
+1   And Peavey jumped on that train, giving the name UNITY to a line of mixers.

Maybe we could define it as "like a unit" or "possessing the quality of a unit". 

You know: "unit-y".
Title: Re: Fader as compared to main levels
Post by: Tommy Peel on January 16, 2014, 04:17:29 PM
Dan- please disabuse yourself of the notion of "unity" as it applies to fader position or the level of a signal.  There ain't no such critter, and Mackie's marketing dept should have been shot for giving this marketing effort the patina of science.

Mackie did love that "Unity" gain marketing stuff... It's all over the user manual for my Onyx 1640

(http://i.imgur.com/xcitdgT.png)

(http://i.imgur.com/Xu71ETO.png)

Note: I'm not implying that anything the the screengrabs is good or useful advice...  ;D
Title: Re: Fader as compared to main levels
Post by: Steve M Smith on January 16, 2014, 04:23:21 PM
 
Quote
Once you have adjusted the input signal to line level, you can set every control to "U" and your signals will travel through the mixer at optimal levels

Not much point in having those controls then!


Steve.
Title: Re: Fader as compared to main levels
Post by: g'bye, Dick Rees on January 16, 2014, 04:28:38 PM
"Once you have adjusted the input signal to line level, you can set every control to "U" and your signals will travel through the mixer at optimal levels"


Not much point in having those controls then!


Steve.

Yeah.  How are you supposed to make everything louder than everything else???
Title: Re: Fader as compared to main levels
Post by: Jason Lucas on January 16, 2014, 04:31:59 PM
The "attenuator" on the main bus of the Roland consoles reduces the level of signals before the main fader, not after, it is not the same as turning down your amps.

I also use a Roland console and have had good success with running my signal level around -18dBFS. I generally take it down a click if it hits the -6dBFS mark, and I treat -3dBFS as my maximum limit. This way none of my channels ever clip, but I still get plenty of signal to work with.

I generally have my main fader set so that the majority of my channel faders are operating at or slightly below 0.
Title: Re: Fader as compared to main levels
Post by: g'bye, Dick Rees on January 16, 2014, 04:51:40 PM

I generally have my main fader set so that the majority of my channel faders are operating at or slightly below 0.

Zero what?
Title: Re: Fader as compared to main levels
Post by: Jason Lucas on January 16, 2014, 04:55:31 PM
Zero what?

The "0dB" point on the fader.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 16, 2014, 05:13:22 PM
Regarding the attenuation, I see what you mean and agree it's not the same as turning down the preamp. From a practical point of view, how would this difference matter to me? I just looked at the block diagram (which I should have done already...sorry), and I can see that there's a bunch of processing after the attenuator. The attenuation would reduce the signal level going to these things. Is it correct to assume this wouldn't necessarily be the best approach if all I want to do is to make the overall mix not-so-loud? Would I be negatively impact SNR?

Also, when you say that you run your signal at -18dBFS, are you talking about the levels of the channel signals out of the preamp? I think you are but I wanted to make sure.

Thanks,
Dan


The "attenuator" on the main bus of the Roland consoles reduces the level of signals before the main fader, not after, it is not the same as turning down your amps.

I also use a Roland console and have had good success with running my signal level around -18dBFS. I generally take it down a click if it hits the -6dBFS mark, and I treat -3dBFS as my maximum limit. This way none of my channels ever clip, but I still get plenty of signal to work with.

I generally have my main fader set so that the majority of my channel faders are operating at or slightly below 0.
Title: Re: Fader as compared to main levels
Post by: Jason Lucas on January 16, 2014, 05:26:36 PM
Regarding the attenuation, I see what you mean and agree it's not the same as turning down the preamp. From a practical point of view, how would this difference matter to me? I just looked at the block diagram (which I should have done already...sorry), and I can see that there's a bunch of processing after the attenuator. The attenuation would reduce the signal level going to these things. Is it correct to assume this wouldn't necessarily be the best approach if all I want to do is to make the overall mix not-so-loud? Would I be negatively impact SNR?

Thanks,
Dan

If the signal coming out of the console is too hot I'd rather turn down the main fader than engage the attenuator. Otherwise I'll be pushing my channel faders up higher. If you're using one of the GEQs on the main output then the attenuator will go before the GEQ, if you're overloading the input stage of the GEQ you could engage the attenuator to reduce the level going into that, but I'd just as soon raise the level of the main fader and reduce the level of my input channels. The GEQ is usually the only processing that will be on the main output unless you use effects or the 4-band EQ in addition to the GEQ (I don't do either).

I like to keep it simple and have as few volume controls in the chain as possible. If I'm hitting the main bus too hard I raise the main fader and turn down my input channel faders.

Also, when you say that you run your signal at -18dBFS, are you talking about the levels of the channel signals out of the preamp? I think you are but I wanted to make sure.

Yes, I always set my metering to "preamp" on the Roland consoles and set my preamp level so that I'm hitting about -18dBFS most of the time. Works fine for most things, some signals need a tad more headroom.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 17, 2014, 03:17:25 PM
Thanks again for all the help.
This morning, I messed with the console a bit. I experimented with two microphones. One of them is for lectors. It's a condenser microphone. The other mic I tried was a Shure SM58 (dynamic). As it turns out, the overall output volume level I got with the SM58 seems to be in the right range. I set the preamp gain so the signal was about -12dBFS. The channel and main faders were set to about -6dBFS and the associated subgroup was set to 0dB. It was plenty loud but not ridiculously loud. I suppose I could turn down the power amp a bit, but for now I'm not going to.
What puzzled me was the loudness with the condenser mic. With the input gain set such that the signal level was also -12dBFS and main fader set the same as above, I needed to reduce the channel fader significantly to get the same loudness as with the dynamic mic. I was expecting that if the signal level coming from the preamp was the same for both mics, the fader settings for the channel and the mains would more or less be the same. What am I missing? Note that the dynamic mic was plugging into a channel that was going through a subgroup while the condenser mic wasn't, but the subgroup fader was set to 0dBFS so, as far as I understand, this shouldn't have changed the signal level.
Title: Re: Fader as compared to main levels
Post by: Tommy Peel on January 17, 2014, 03:51:46 PM
Thanks again for all the help.
This morning, I messed with the console a bit. I experimented with two microphones. One of them is for lectors. It's a condenser microphone. The other mic I tried was a Shure SM58 (dynamic). As it turns out, the overall output volume level I got with the SM58 seems to be in the right range. I set the preamp gain so the signal was about -12dBFS. The channel and main faders were set to about -6dBFS and the associated subgroup was set to 0dB. It was plenty loud but not ridiculously loud. I suppose I could turn down the power amp a bit, but for now I'm not going to.
What puzzled me was the loudness with the condenser mic. With the input gain set such that the signal level was also -12dBFS and main fader set the same as above, I needed to reduce the channel fader significantly to get the same loudness as with the dynamic mic. I was expecting that if the signal level coming from the preamp was the same for both mics, the fader settings for the channel and the mains would more or less be the same. What am I missing? Note that the dynamic mic was plugging into a channel that was going through a subgroup while the condenser mic wasn't, but the subgroup fader was set to 0dBFS so, as far as I understand, this shouldn't have changed the signal level.

To put it simply different mics have different output levels. IME condenser mics tend to be hotter and require less gain to get the same signal level as a dynamic. What you're experiencing is perfectly normal. You'll want to set each channel so that it averages -18dBFS(or 0dB in Analog Land like I am) regardless what position the gain knob ends up in.

Here's the gain knobs(top row) on my mixer; most of the channels end up averaging 0dB(which is equivalent to -18dBFS for you).
(http://i.imgur.com/jJF7h9j.jpg)
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 17, 2014, 03:58:55 PM
What you described is what I expected. However, what I found (or think I found) is that, even when the signal level was the same coming out of the preamp, the condenser mic was louder than the dynamic mic (with channel and main fader settings the same for both mic types). This makes no sense to me at all. If the consensus is that this isn't possible, then there must be something else going on with the settings for the two channels I used.

To put it simply different mics have different output levels. IME condenser mics tend to be hotter and require less gain to get the same signal level as a dynamic. What you're experiencing is perfectly normal. You'll want to set each channel so that it averages -18dBFS(or 0dB in Analog Land like I am) regardless what position the gain knob ends up in.

Here's the gain knobs(top row) on my mixer; most of the channels end up averaging 0dB(which is equivalent to -18dBFS for you).
(http://i.imgur.com/jJF7h9j.jpg)
Title: Re: Fader as compared to main levels
Post by: Patrick Tracy on January 17, 2014, 04:07:43 PM
I set the preamp gain so the signal was about -12dBFS. The channel and main faders were set to about -6dBFS and the associated subgroup was set to 0dB.

Numbers in the dBFS and dBu scales indicate absolute signal levels. Fader settings in dB simply add to or subtract from the level. It's a critical distinction.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 17, 2014, 04:46:16 PM
Ok, but shouldn't I expect that with the same signal level going into the channel section, the same fader setting would result in the same perceived loudness, regardless of the mic type?

Numbers in the dBFS and dBu scales indicate absolute signal levels. Fader settings in dB simply add to or subtract from the level. It's a critical distinction.
Title: Re: Fader as compared to main levels
Post by: Patrick Tracy on January 17, 2014, 04:53:13 PM
Ok, but shouldn't I expect that with the same signal level going into the channel section, the same fader setting would result in the same perceived loudness, regardless of the mic type?

More or less, but frequency content can make perceived loudness diverge from objective measures.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 17, 2014, 05:06:57 PM
I don't think what I heard was due to differences in frequency content; it was me saying "check" a lot in both cases :). I know the mics will have different frequency responses, but the channel fader difference was at least 10dB. I guess the next step would be to plug both mics into exactly the same channel and A/B them that way. Maybe there's a difference in the channel settings that I'm missing or the subgroup is doing something I'm not expecting.
Thanks :)

More or less, but frequency content can make perceived loudness diverge from objective measures.
Title: Re: Fader as compared to main levels
Post by: Tommy Peel on January 17, 2014, 05:37:48 PM
What you described is what I expected. However, what I found (or think I found) is that, even when the signal level was the same coming out of the preamp, the condenser mic was louder than the dynamic mic (with channel and main fader settings the same for both mic types). This makes no sense to me at all. If the consensus is that this isn't possible, then there must be something else going on with the settings for the two channels I used.
Just re-read your post that I responded to and had misunderstood what you were looking at. IMO unless you think you're having some issues with your console you may be overthinking this a bit. I set my gains for an average around 0dB(but never clipping) initially and if the channel fader ends up in the "butter zone" around 0dB I call it good. If a certain channel ends up out of the "butter zone" I adjust the channel gain accordingly if it's a channel that requires very much attention. If all the faders are riding too low or high you can adjust the main fader or system gain to compensate too though my main fader is almost always at 0dB.

Slightly related story:
One time we were doing a gig(youth rally) in a pavilion instead of the small church we usually play in and I was getting some distortion(clipping) on the vocal channels though no red lights were illuminating on the board.... I had(and still do have) a Shure DFR11EQ digital equalizer setup so that the vocals came out of sub group 3, went to the DFR, and came back to the mixer though an open aux return(I don't have any subgroup inserts). Anyway after scratching my head a few minutes(this was during the soundcheck/practice) I looked at the rack(below the mixer) and saw the red light coming on sporadically on the DFR. Ended up pulling the subgroup fader down several dB and raising the aux return level to compensate and everything was fine for the rally.
Title: Re: Fader as compared to main levels
Post by: Jason Lucas on January 17, 2014, 08:03:11 PM
Dan you said you use an M-200i, right?

(http://img.photobucket.com/albums/v332/Master_Razor/RolandM200i_zps8b838572.png) (http://smg.photobucket.com/user/Master_Razor/media/RolandM200i_zps8b838572.png.html)

I set the "sensitivity" knob (red knob in picture) to wherever it needs to be so that my meter hovers around -18 (also highlighted in red). Sometimes this setting is different for different inputs. Sometimes it's different for two different people using the same mic (we have one singer I set to -13 and another to -20, same mic). I usually have my main fader somewhere around -3dB. If I need more or less main to get all my channel faders to be roughly around 0dB, I turn it up or down.

Signal level and perceived volume are very different. Just the other day had two people both talking in two different mics, had their signal levels very close to each other, but one of them sounded much louder so I had to have about a 6 or 7dB difference on the faders.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 17, 2014, 08:58:56 PM
Thanks Jason.
It sounds like I'm doing everything as you described. And, I totally get what you're saying about how loud different people sound. Some people's voices just cut through more than others. This is probably related to the frequency content of their voices.
Anyways, I'm still stumped but I suspect I'm going to find a console setting to explain what I saw. I'm still learning the M200i so I'm not that familiar with where all the controls are. You'll probably see a post from me soon which includes the word "duh..." :)
Dan
 

Dan you said you use an M-200i, right?

(http://img.photobucket.com/albums/v332/Master_Razor/RolandM200i_zps8b838572.png) (http://smg.photobucket.com/user/Master_Razor/media/RolandM200i_zps8b838572.png.html)

I set the "sensitivity" knob (red knob in picture) to wherever it needs to be so that my meter hovers around -18 (also highlighted in red). Sometimes this setting is different for different inputs. Sometimes it's different for two different people using the same mic (we have one singer I set to -13 and another to -20, same mic). I usually have my main fader somewhere around -3dB. If I need more or less main to get all my channel faders to be roughly around 0dB, I turn it up or down.

Signal level and perceived volume are very different. Just the other day had two people both talking in two different mics, had their signal levels very close to each other, but one of them sounded much louder so I had to have about a 6 or 7dB difference on the faders.
Title: Re: Fader as compared to main levels
Post by: David Morison on January 18, 2014, 10:34:56 AM
I set the preamp gain so the signal was about -12dBFS. The channel and main faders were set to about -6dBFS and the associated subgroup was set to 0dB. It was plenty loud but not ridiculously loud.

<snip>
What puzzled me was the loudness with the condenser mic. With the input gain set such that the signal level was also -12dBFS and main fader set the same as above, I needed to reduce the channel fader significantly to get the same loudness as with the dynamic mic. I was expecting that if the signal level coming from the preamp was the same for both mics, the fader settings for the channel and the mains would more or less be the same. What am I missing? Note that the dynamic mic was plugging into a channel that was going through a subgroup while the condenser mic wasn't, but the subgroup fader was set to 0dBFS so, as far as I understand, this shouldn't have changed the signal level.

Remember what I said right at the start of the thread about consoles often reducing signal level at bus or main fader stages to prevent overdriving them?
Sounds like you've just discovered exactly that.
Or, there may be some setting on the subgroup, like maybe a compressor engaged, that you've overlooked.
Cheers,
David.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 18, 2014, 11:00:06 AM
Yeah, I remember :)...
But, I must be missing some setting because, in both cases, I was only using one input so I can't imagine why the console would be automatically messing with one signal and not the other.
Dan

Remember what I said right at the start of the thread about consoles often reducing signal level at bus or main fader stages to prevent overdriving them?
Sounds like you've just discovered exactly that.
Or, there may be some setting on the subgroup, like maybe a compressor engaged, that you've overlooked.
Cheers,
David.
Title: Re: Fader as compared to main levels
Post by: David Morison on January 18, 2014, 11:12:24 AM
Yeah, I remember :)...
But, I must be missing some setting because, in both cases, I was only using one input so I can't imagine why the console would be automatically messing with one signal and not the other.
Dan

The gain reduction at subgroups, if present, is almost certainly static rather than varying dynamically per number of channels used - going back to analogue terminology, hardwired.
David.
Title: Re: Fader as compared to main levels
Post by: Dan Crocker on January 18, 2014, 04:07:39 PM
Ok, I went back and played more. I think the loudness difference I was hearing was a combination of listening position, EQ, and slightly different input signal levels. I spent a little more time setting the input gain for the different mics. As of now, I think the console is behaving as I expected.
Thanks for all the help!
Dan