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Gain staging on mixer


Shu83kk
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Hi everyone I have another of my doubts about helix!  I read around that by connecting helix directly to foh you have to do gain staging, so in theory you have to add the various blaches without these exceeding the signal of an empty preset so with the bypassed blocks (except the boosts for example), my question is the following: How do I get the same level as an empty preset when it comes to amp blocks?  Shouldn't a clean with the same volume be heard more than a distorted sound, which is heavily hit and gets lost in the mix?  I hope I explained myself well thank you very much

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Blaches?

 

Gain staging is a necessity whether you're using a Helix to FOH or an analog pedal board and a Marshall stack with a microphone.

 

Take any of the sample presets (or one of your own). Highlight the Output Block. Play as hard as you ever play with all gain blocks active. Turn up your Channel Volume (or the last Gain block) until the Output Block hits the red, then back off until it stays green. You now have the optimum output level for the preset.

 

But will it sound good? Not necessarily.

 

Gain staging means making sure that each block's output does not overload the next block UNLESS that's the effect that you're going for. When you get to the end of the signal chain repeat the above output block procedure. You now have a properly gain staged preset with the optimum output level.

 

If the FOH person says "Your signal is too hot! Turn it DOWN!" they're probably the bartender multitasking as sound tech. They have an Input Gain control on the board and usually a PAD switch. If they don't know how to use their board, then to get through the gig you may have to assign the BIG KNOB to the output you're sending to FOH (that should usually be assigned elsewhere so that FOH gets a consistent signal) and use the BIG KNOB to compensate for the house's crappy board or the incompetence of the "sound tech".

 

That whole thing about the overall level needing to equal the level of an empty preset is BS in theory and BS in practice.

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If you've been playing live you've been gain staging whether you wanted to or not regardless of the equipment or setup you're using..  Always have and always will.  This is because all mixing boards in my lifetime of almost 70 years requires each input signal to be within a certain consistent range so that it won't distort or cause problems on the channel it's coming into.  The only difference with the Helix is you can ensure every preset is gain staged accurately on the output side so that the sound man only has to adjust your input level once and it will be good for every preset or snapshot you play.

As rd2rk mentioned the whole "not exceeding the signal level of an empty preset" is nonsense and has been dismissed for many years now.  What you do have at your disposal is a signal meter on your output block that, if selected will give you a rough idea of where your signal strength is sitting on your preset.  When I was depending on that for gain staging I'd typically shoot for around  70% and the soundman can then adjust it up or down to fit his needs at the board.  You have to bear in mind however that only measures the digital signal level, not the ultimate analog level that gets sent out of the XLR or 1/4" output.  For that reason the most common guidance and simplest to deal with is to configure your global settings so the main Helix volume knob is disabled (which sends a non-attenuated audio output signal) and set your XLR output to send Mic signal level which is the most common signal level used for mixing boards.

I have hundreds of presets that I've built over the last 7 years and I wouldn't be afraid of plugging any of them into any PA system and would expect all to work perfectly and be easily gain staged on any mixing board.

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All of the above is great material.  To make it more concise....

 

 

Gain staging is just a fancy term for making sure the output of one piece of equipment (or block in the helix) doesnt exceed the input level the next piece of gear (or block in the Helix) needs in order to do its job properly.  

 

It doesnt take much to do this properly, but also doesnt take much to make this a mess if you dont do it properly.  

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So I just look at the vu meter of the mixer and try not to just clip, leaving the history of the bypassed blocks alone, I hope I have understood correctly!  One more thing, does the sound engineer use the right gain / trim to lower or raise my signal?  But doesn't he distort the sound a bit regardless, or does he have to boost it to clipping?  Excuse me if I ask silly questions, but before I was the type of analogue kick head and pad and I still miss a few things !!Thanks for the replies anyway

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I think this thread is about what you, as a player, can do with your modeler to give FOH the best signal possible, the IDEAL being that they can set your channel levels once and forget about you. You DO NOT want a mystery "sound engineer" constantly futzing with your mix.

 

That means sending a consistent signal that you've designed, as far as is in your power, to sound good in your band's mix.

 

What it's NOT about is what you would do at the board. Unless it's your PA and you're the one doing the mixing, you have little if any control over that.

 

If it IS your PA and you are the one doing the mixing, do you really want to have to be constantly messing with the mix while you're trying to play?

No. So your job is the same as it would be if you're depending on a house PA and a mystery sound engineer.

 

Send a consistent sound that fits in your band's mix with minimal fuss.

 

Above are some suggestions as to how to approach that goal with Helix.

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On 9/19/2022 at 7:26 PM, Shu83kk said:

So I just look at the vu meter of the mixer and try not to just clip, leaving the history of the bypassed blocks alone, I hope I have understood correctly!  One more thing, does the sound engineer use the right gain / trim to lower or raise my signal?  But doesn't he distort the sound a bit regardless, or does he have to boost it to clipping?  Excuse me if I ask silly questions, but before I was the type of analogue kick head and pad and I still miss a few things !!Thanks for the replies anyway

Just to be complete and give you a better understanding...a key aspect of doing a sound check is to gain stage each instrument channel coming into the mixing board so they're all at a consistent signal level with adequate headroom so they can then be mixed with the faders and not cause have any problems clipping.  This level varies board to board and engineer to engineer, but is at the core of how a mixing board is setup.

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All these theories about "gain staging = output level must match input level" are plain BS (especially in the digital audio), so just ignore everyone saying stuff like that.

 

You can do whatever you want with your presets. As soon as the output isn't clipping or producing signal distortion, and there is some headroom, you are good.

 

 


 

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I've posted a related question in the Powercab forum but it doesn't get much traffic there these days so I hope you don't mind the repost here.

 

My presets are pretty consistent output-wise but need a 'bump' to get into the amber when I play through the Powercab. Everything I've seen (including Jason Sadites videos) advocates setting preset levels individually for the Powercab - is there any reason NOT to increase the digital output level in global settings so that I can 'bump' them all at once rather than individually? This would save me a lot of re-work.

 

TIA. 

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"Pretty consistent" is not "equally level". Neither average nor median means equally level.

But, hey, if you want to try that, go for it! It won't cause the magic smoke to escape from either your Helix or your Powercab.

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On 9/22/2022 at 2:29 PM, jpspoons said:

I've posted a related question in the Powercab forum but it doesn't get much traffic there these days so I hope you don't mind the repost here.

 

My presets are pretty consistent output-wise but need a 'bump' to get into the amber when I play through the Powercab. Everything I've seen (including Jason Sadites videos) advocates setting preset levels individually for the Powercab - is there any reason NOT to increase the digital output level in global settings so that I can 'bump' them all at once rather than individually? This would save me a lot of re-work.

 

TIA. 

 

In general a global bump isn't a great move, unless your tone palette (in terms of transient dynamic and volume pressure) isn't moving to much between presets.

 

BTW, isn't about powercabs. IME, it's all about sending "vivid" signals out of the Helix, no matter the monitors. For some reason people seems obsessed to keep load of headroom, producing extremely weak output for no valid reason.

 

If you balance your presets to stay solid and closer to the headroom ceiling (without breaking it), you are good with any monitoring system.

 

Of course it also depends on the tone; a super glassy clean tone has LOAD of transients, so it does need more headroom... but from overdrive to high gain, keeping load of headroom is just a waste (and a problem for speakers that needs proper pressure to sound as they should).

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Except in his case, I believe it is about the Powercab because they say the light should be amber to get the best tone.  I have the powercab and use the preset powercab settings to give it a boost.  I have the PC settings so it is global and that works just fine for me.  Most of my presets are close level wise so this works for me.... of course, your mileage may vary :)

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On 9/22/2022 at 10:10 PM, PaulTBaker said:

Except in his case, I believe it is about the Powercab because they say the light should be amber to get the best tone.  I have the powercab and use the preset powercab settings to give it a boost.  I have the PC settings so it is global and that works just fine for me.  Most of my presets are close level wise so this works for me.... of course, your mileage may vary :)

 

In all honestly, the yellow led thing is a bit of snake oil, even because yellow/red are very transient sensitive, like any headroom range in a non linear dB scale. It's just a meter measuring input before the amp stage.

 

Also, the original version of the manual says the yellow/amber does indicates that level is close to the hardware limit (which is true). Then people started complaining about PCs being weak, and then they added the "yellow = most realistic non-linear natural breakup characteristics", to invite users to push their preset at the output.

 

Amber just indicate you are close to the limit of the available headroom at the converters, but doesnt mean "best tone", or speaker breakup zone. You can get amber zone, even with PCabs at volume zero, so hundred miles away from breakup. 

 

Also, good luck staying in the yellow with clean tones without injecting noise for no reason, and risking transients blowing up the speakers at higher volumes..:)

 

From green to yellow, is all good. For compressed signals, you can stay more on the yellow, for cleans and non-guitar signals  better to stay on the green.

 

Again, just do good preset leveling, and you are good, without staring at the powercab led (also on top of the cab, so bloody annoying to control)

 

100% imho.

 

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On 9/22/2022 at 8:29 AM, jpspoons said:

I've posted a related question in the Powercab forum but it doesn't get much traffic there these days so I hope you don't mind the repost here.

 

My presets are pretty consistent output-wise but need a 'bump' to get into the amber when I play through the Powercab. Everything I've seen (including Jason Sadites videos) advocates setting preset levels individually for the Powercab - is there any reason NOT to increase the digital output level in global settings so that I can 'bump' them all at once rather than individually? This would save me a lot of re-work.

 

TIA. 

 

Off the top of my head, I don't know of any way to just bump up the volume globally into the Powercab. Which global setting are you using?

 

Maybe you could use the Global EQ but I don't think this works via L6 Link. I know it didn't used to. I think you would have to be connected via XLR which is a big hit to the functionality on the PowerCab+, versus being connected from a Helix via L6 Link. 

 

Anyway, back to boosting all presets via one easy global adjustment. I like it! Maybe some presets that require further volume adjustment; raising them all the same amount doesn't guarantee they will stay leveled with each other. The ease of this approach is very appealing though.as an alternative to painstakingly editing a custom set of presets, tailored individually to the PC, which is what I have done.

 

 

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On 9/23/2022 at 9:08 AM, HonestOpinion said:

 

Off the top of my head, I don't know of any way to just bump up the volume globally into the Powercab.

 

 

 

Yeah, the PCs have 3 dedicated params to bump the level. Globally, in the main settings, you can edit INPUT 1 and INPUT 2 gain, in the range of -96.0 to +12.0.

 

Then, you can edit the Level per preset, in the range of -60.0dB to +6.0dB

 

They works very good for little bumps, but then it's digital hiss fest, as you raise the noise a lot.

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@HonestOpinion you're right, global EQ doesn't impact digital outs - I wish it did though, and there's at least one request for this on Ideascale.

 

The setting I was hoping to use is this one (page 3, knob 6) - disclosure, I haven't tried it yet, hence the question here, but I was *assuming* it would allow me to bump all my patches by say +3dB if that's enough to hit amber. I have started to set up patches with a footswitch for Helix cab vs Powercab speaker... so if this works, I could keep all my current patches which work fine through XLR outs and be able to switch between Powercab and direct as the situation dictates.

https://helixhelp.com/tips-and-guides/helix/global-settings#page-3

 

@PierM I think you're saying that Powercab green is fine though - in which case I don't need to make any changes at all!

 

What a time to be alive :-D

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On 9/23/2022 at 3:19 PM, jpspoons said:

 

@PierM I think you're saying that Powercab green is fine though

 

 

Of course it is! Have you ever seen an audio equipment where green flashing on a input meter means something bad? :)

 

No led at all or most of the time, means your input it's too weak, and too close to the noise floor, so if you pump the volume on the PC to bring back some signal, you will end with lot of hiss/noise from the floor. Green means you are far enough from noise floor and far from clipping. Yellow means you are reaching the ceiling of the input stage and headroom is very narrow, red means you cross it, and the input stage is being overloaded. Powercabs are more like studio monitors than a guitar amplifier, so it's better to stay away from clipping both analog and digital sections.

 

BTW, that "yellow led theory", never been about quality of the tone (even Sadities never really wanted to said that imho), but a matter of "perceived" volume and sound pressure available from the powercabs, when people needs more, for any reason. I would say, in a perfect scenario, with a fat and busy high gain preset (properly leveled at the amp stage and at the output), the yellow peaks would just be a natural consequence. But forcing all presets to peak in the yellow (which does represent a very narrow dB range close to the headroom ceiling), it's a plain nonsense because guitar can be either hugely dynamic signal (jazz, blues, finger picking etc...) or super normalized and compressed signal (high gain, compressors, metal rythm etc..). That wide spectrum of tones, it can't all be forced to blink the yellow. That's a laughable goal at best.

 

100% imho, as always.

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Green just means the PC is receiving a signal. It doesn't need to be in the amber zone all the time, but you should get it up there and then back off a bit to leave headroom.

 

If you're good on the digital outs you should be good on the analog, but that assumes that you're not using the BIG KNOB to control the output level on either. Leave it dimed or set it to an output that you're not using (preferred). That gives a consistent UNITY gain level.

 

The digital Output level applies to the AES/SPDIF outs, not the XLR/1/4" outs.

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ok, lots of things:

1.   I have never used the digital Output level, (didn't really know or think about it).  What I use is on the Output block of the preset under the PowerCab tab.  I have it set to global and adjust the level there for all presets.

 

2. most of my presets are set to hit a meter at -14 to 11-db so I don't believe the noise floor comes into play.  

 

3. when playing, I don't really watch the PC lights unless something sounds off, so I don't really worry about green vs yellow... i will do something if it stays in the red.  bumping the red every now and then has not caused much of a problem for me.

 

 

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I guess I'd been thinking that my preset outputs were ok at analogue level, but needed an increase to hit the "optimal" digital level (Powercab amber) - and I was hoping to use the digital output global to do this without impacting the analogue output level.

 

So now I think 

 - I could probably go into each preset and change the output block level like @PaulTBaker , without adversely affecting my XLR outputs after all. Or...

 - I could increase the digital output level globally, but might still need to tweak each preset to get to the "perfect" amber LED. 

 - But... neither of those will actually be a significant benefit, because the amber LED on the Powercab doesn't actually make that much difference - thanks @PierM

 

So at the risk of making myself stoopid, I may as well put it out there that I've never had a problem with the Powercab being too quiet, so I'm probably trying to fix a problem I didn't even have in the first place - I was just trying to follow the best practice advice :-/

 

Note to self - spend less time on the internet figuring out what to do, and more time actually doing. Thanks for the input everyone.

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On 9/23/2022 at 4:32 PM, jpspoons said:

- I could probably go into each preset and change the output block level like @PaulTBaker , without adversely affecting my XLR outputs after all. Or...

 

Yes, this works. Just be aware that when you set REMOTE to GLOBAL, that is GLOBAL to ALL Helix Presets, and you are NOT using L6 Link for any of the other possible per preset parameters such as MODE (FRFR LF Flat/LF Raw) or SPEAKER. PER PRESET CONTROL IS DISABLED! If you're using MIDI for those parameters it doesn't matter.

 

On 9/23/2022 at 4:32 PM, jpspoons said:

 - I could increase the digital output level globally, but might still need to tweak each preset to get to the "perfect" amber LED.

 

Yes, This works. But ONLY affects the DIGITAL OUTS. Your XLR Outs are unaffected. The difference between the DIGITAL OUTS (at 0db) and the XLR OUTS (at 0db and LINE LEVEL) is <>6db with DIGITAL being LOUDER. So, if you set your PC's XLR INPUTS at +6db the levels should be approximately equal.

Forget the "perfect" amber LED. As @PierMsaid, its main purpose is to indicate where you're starting to run out of headroom.

 

On 9/23/2022 at 4:32 PM, jpspoons said:

- But... neither of those will actually be a significant benefit, because the amber LED on the Powercab doesn't actually make that much difference

 

Not to the overall TONE when above Fletcher-Munson (<>85db).

To the MAX AVAILABLE OUTPUT LEVEL without distorting the PC's Inputs it DOES make a difference.

Again, as @PierMsaid, too low and it brings up the noise floor when you adjust the Output Level to compensate.

 

However, if your PC is loud enough for your purposes then no, it doesn't matter that much.

 

Bottom line - the MOST important thing is that, using DIGITAL or ANALOG inputs, when changing presets, your presets need to:

NOT be so high as to distort the PC's inputs.

NOT be so low as to cause you to drop out of the mix.

If they're mostly level to your ears, you should be good.

 

HOWEVER - 

 

If you're using the PC's XLR OUTS to go to a board, the level at the XLR OUTS = the INPUT LEVEL, NOT the PC's overall Output Level.

IOW - the PC's VOLUME KNOB has no effect, but the Helix Volume Knob DOES! That's why I disable the BIG KNOB when going to FOH. 

If, for instance, your cable drags across the BIG KNOB and changes it from noon to MAX, you'll have a VERY unhappy sound tech!

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