Calibrating Input Level for Plugins

[MirrorProfiles]

So using this knowledge, Scarlett input set to minimum, (bass plug-in input and output gain set to 0) looking at the waveform before and after, the one set “correctly” produces a flat line, whereas the one recorded the lowest led way (maxing input to just below red) has all the waves.

Is this normal? (Before on the right, new on the left)

View attachment 9708

Should be an option in your DAW to adjust how zoomed in the waveform view is. Here is a single coil telecaster played pretty gently at 11.4dBu of headroom (its tiny when fully zoomed out, totally squared off totally zoomed in). Just adjust the view until you can see a useful portion of the waveform. Its normal to have to see in TINY detail as well as mostly just the transients. The zoom should allow whatever you need to be visible

 

[Whizzinby]

View attachment 9709
Should be an option in your DAW to adjust how zoomed in the waveform view is. Here is a single coil telecaster played pretty gently at 11.4dBu of headroom (its tiny when fully zoomed out, totally squared off totally zoomed in). Just adjust the view until you can see a useful portion of the waveform. Its normal to have to see in TINY detail as well as mostly just the transients. The zoom should allow whatever you need to be visible

Yeah so from the main grid it just looks like flat lines, but when I select a track I see a wave form closer to what I’m accustomed to.

See the flat line in the main grid but waveform in the bottom window when selected:

Perhaps I’m just used to seeing a really apparent waveform from the main grid.

 

[StratsoundFan]

It is extremely counterintuitive, but these amp sims do sound best with the gain knob turned all the way down, assuming the input trim in the amp sim is adjusted according to the specs of an audio interface being used.

 

[MirrorProfiles]

If you expand the track width and zoom in, is there enough to work with?

If its a low output pickup played soft, you might have to zoom a bit more but it should be loud enough to see well. If you are used to seeing waveforms that are just below clipping, then everything is going to look quiet by comparison, its normal that itll take getting used to it visually.

 

[TheTrueZoltan!]

@Whizzinby Take a look at the upper right corner of Logic. There's the waveform zoom. Click to activate. As far as I remember the zoom is set to -6dBFS by default, but you can change that by dragging up and down.

 

[Whizzinby]

@Whizzinby Take a look at the upper right corner of Logic. There's the waveform zoom. Click to activate. As far as I remember the zoom is set to -6dBFS by default, but you can change that by dragging up and down.

View attachment 9712

#nailedit

This is turning into a GeekSquad session.

You dudes rock.

 

[SwirlyMaple]

This last handful of replies is a great example of why plug-in vendors SHOULD care about this. (Edit: to clarify, I mean that many experienced users aren’t aware of it.)

How many times have we heard “X plugin sounds terrible for me” while another person says that same one is incredibly accurate?

It makes a huge difference that the input level to an amp sim is correct. I mean, to a certain extent, this is the reason why some people prefer single-coils and others prefer humbuckers with real amps—because amps sound much different based on the pickups’ output levels.

When vendors say “just dial it up until it’s almost red,” they’ve just taken all their hard work in modeling and characterizing an amp, and thrown a Poop-O-Matic Decalibrator in front of it.

 

[SwirlyMaple]

So with Native I believe it was shared earlier in the thread 0 at the Apollo Twin and Native boosted +1. So does that mean input level in Native is set to + 1 and not -18 to -24 that’s commonly referenced?

Just to be really clear about this, I think your statement is mixing two things.

When we say in this thread that Native should be set to 0.0dB, for example, we're referring to the value it shows in green above the dB meter in Native when you hover over the adjustment slider. The default value IS zero, as shown below:

The oft-cited recommended peak level in Native is -18dB, which is referring to the peak level shown on that meter when you're strumming hard, NOT the slider setting. You adjust that peak level by moving the slider. You don't have to do any of that if you know the calibration value, which is what this thread is about. You can ignore the "-18dB peak" recommendation, and simply set the value of the slider according to the known conversion spec of your interface. This should be much more accurate than eyeballing a -18dB peak and adjusting the slider.

 

[Elf]

HX Stomp hits -12.3dBFS with 0.707v RMS at the input, you need to lower by -0.7dB to reach -13dBFS.
Or you can leave it as is, -0.7dB is nothing.

Thanks for this info!

 

[MirrorProfiles]

The level we used was in relation to UAD Unison sound card, basically with the UAD gain knob turned completely left, I matched it with an RME card, and on it is +16db to keep the same level also in the NA amp plugins.

Courtesy of Igor Nembrini (to someone else that they shared with me). Makes sense given many of the BX amp sims he coded were released on the UAD platform first. Nice to have it confirmed, and also kudos to Igor for being approachable and friendly in every exchange.

 

[James Freeman]

I don't understand what he says.

 

[MirrorProfiles]

I think he is saying that they're designed for UAD interface gain at 0.

With his RME (I checked facebook photos and he seems to have a Fireface UFX II), it has the specs:

"Maximum input level, Gain 8 dB: +21 dBu"

So boosting another 8dB or so to get to 16dB (as the RME input gain) would be pretty close to that UAD reference level.

 

[storming heaven]

I've been following this thread for a while; at first I was thinking "nah, it wouldn't matter that much" regarding input volume and to be honest I was somewhat lazy to do the calculations by myself. Then I figured, I would get a volt meter and get my hands dirty but thanks to the calculations by @James Freeman and @MirrorProfiles I found the true input levels for my audio interface (Audient EVO 4 - 10dBu) and I couldn't be happier.

I always thought something was off in the amp sims that I was using. I always used the 'gain as much as you can without clipping and you are set' philosophy; which I blame the internets for this, but once I lowered the input gain on my interface and adjusted depending on the amp sim (or profile), it all made sense; the feel, the sound and everything else.

By the way, I have reached out to Bogren Digital and ML Sound Lab technical to learn about their preferred levels, but their response was the usual "near clipping, but not too much... play what sounds good." With my interface, adding about 5-6 db of volume before the amp sims seems to do the trick, though I know that it won't be as exact as other sims for which we know the preferred input levels of.

 

[James Freeman]

For people who are using AxeFx3 as their interface into Helix Native with SPDIF/USB;
Lower the digital Output by exactly -12dB to match Helix input voltage.
I have measured both Helix and AxeFx3 with 1vAC RMS test signal from my audio interface and confirmed it's accurate to 0.1db.

Note, this is not the hidden +18dB boost that AxeFx adds to the digital Inputs.
To fix this permanently go to Setup -> I/O and lower all USB/AES/SPDIF Inputs by -18dB.

 

[Orvillain]

For people who are using AxeFx3 as their interface into Helix Native with SPDIF/USB;
Lower the digital Output by exactly -12dB to match Helix input voltage.
I have measured and confirmed it's accurate to 0.1db.

Note, this is not the hidden +18dB boost that AxeFx adds to the digital Inputs.
To fix this permanently go to Setup -> I/O and lower all USB/AES/SPDIF Inputs by -18dB.

I've got the -18dB perma-adjustment on the SPDIF/AES one. I haven't on the USB ones because I don't use USB for audio with the Axe. But are you saying to also do another -12dB when using Helix Native ??

So -30dB total ???

 

[James Freeman]

But are you saying to also do another -12dB when using Helix Native ??
So -30dB total ???

No, Input is not Output.

When using the AxeFx Instrument Input (Secret Sauce) you have to lower the SPDIF output by exactly -12dB.
AxeFx Instrument Input -> SPDIF (-12dB), this goes into Native.

The hidden +18dB boost to the digital inputs is a different matter, we don't use them for Native at all.

 

[Orvillain]

No, Input is not Output.

When using the AxeFx Instrument Input (Secret Sauce) you have to lower the SPDIF output by exactly -12dB.
AxeFx Instrument Input -> SPDIF (-12dB), this goes into Native.

The hidden +18dB boost to the digital inputs is a different matter, we don't use them for Native at all.

Right.

So what I see with my setup is, with AES/SPDIF set to 0dB, the DI signal that I record with SPDIF is 18dB louder than what my amplifier sees, confirmed by checking the signal level of my guitar going into my Neve DI and then into the DAW via my Discrete 8.

So I set the AES/SPDIF level to be -18dB so that when I record a DI, I know I can reamp it through my real amplifiers and still hit the front of the amp with the same signal as it would get if I was plugged directly into the amp itself.

I seem to require that -18dB setting in order to get a unity-gain recording of my guitar DI, whilst also being in 4-cable-method with my real valve amps.

 

[contrario]

HX Stomp hits -12.3dBFS with 0.707v RMS at the input, you need to lower by -0.7dB to reach -13dBFS.
Or you can leave it as is, -0.7dB is nothing.

Some guitars with hot pickups can clip the input of Helix Floor or HX Stomp. It's recommended to turn the input pad on which attenuates the input signal 5,7 dB. How should interfaces be calibrated in this case?

 

[riffy]

Color me an idiot. I can't find the spec I need for the Behringer 202hd.. Ugh, I are the stupid.

I finally found something that says that the Max Output is +3. That seems not right though.
I have been leaving it's preamp levels at 0 and adjusting the input gain on the plugs to where
I think they should be by ear. That isn't the optimum method though.

 

[SwirlyMaple]

Note, this is not the hidden +18dB boost that AxeFx adds to the digital Inputs.
To fix this permanently go to Setup -> I/O and lower all USB/AES/SPDIF Inputs by -18dB.

When I:

• Record a guitar DI track into my DAW (USB channel 5)
• Record the stereo output of the FM9 (USB channels 1/2) at the same time
• Run the DI track back out to the FM9 via USB to re-amp it…

it requires that built-in +18dB boost to sound the same as the recorded stereo output. Just a heads-up to people who are re-amping via USB and using the amps in the box.

It almost seems like any time something passes through an input block, including a plugged-in guitar, it gets a +18dB boost, but the DI output on USB5/6 (for the FM9) does not get that same boost.