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Title: Trying to understand how gain works in our console
Post by: Terje Peersen on January 17, 2020, 09:15:56 AM

Hi all!

I've been a sound technician in our church for a while now, and we (still) use a Yamaha LS-9. I feel like I have decent control over the console, at least everything that I need to know. But there is one thing I just can't understand the reason behind, and Google hasn't given me an answer either.

Why does the gain start at +10 for the lowest setting, and goes into minus after 0? How is a signal at -10 stronger than a signal at +10 and not the other way around?

Title: Re: Trying to understand how gain works in our console
Post by: Taylor Hall on January 17, 2020, 09:54:52 AM

As I understand it the +10 setting at the 'bottom' of the gain adjustment is to take line level inputs into account. Basically Yamaha chose to have their headamps operate in terms of sensitivity rather than gain as we all know it. So if you had an incoming signal that peaks at say -32, that's where you'd set your 'gain' on that channel to have it come in at 0db. It's a bit backwards, but makes sense once you wrap your head around it.

Title: Re: Trying to understand how gain works in our console
Post by: Art Welter on January 17, 2020, 11:36:03 AM

Quote from: Terje Peersen on January 17, 2020, 09:15:56 AM

Why does the gain start at +10 for the lowest setting, and goes into minus after 0? How is a signal at -10 stronger than a signal at +10 and not the other way around?

Yamaha has been consistent with labeling "Input level" as the nominal input level, rather than "gain" accepted with the chosen input sensitivity setting.

See section "G" from the PM-1000 manual from over four decades ago, it has a much better explanation than the LS9 manual...

Art

Title: Re: Trying to understand how gain works in our console
Post by: John Roberts {JR} on January 17, 2020, 12:20:08 PM

Quote from: Terje Peersen on January 17, 2020, 09:15:56 AM

Hi all!

I've been a sound technician in our church for a while now, and we (still) use a Yamaha LS-9. I feel like I have decent control over the console, at least everything that I need to know. But there is one thing I just can't understand the reason behind, and Google hasn't given me an answer either.

Why does the gain start at +10 for the lowest setting, and goes into minus after 0? How is a signal at -10 stronger than a signal at +10 and not the other way around?

google "decibels".... technically power ratios, but in this case talking about voltage ratios of how much the inputs signals get boosted.

+10 dB is a voltage ratio of roughly 3x 
0 dB is a voltage ratio of unity or 1:1
-X dB is attenuation

JR