Is visual clipping an "early" warning?

[boynigel]

I noticed on a couple of presets that my effects loop block flickers into the red when i really dig in on my attack, however, i don't hear any clipping.  Seems that a lot of gear these days gives an early visual warning, usually a couple db or so, before actual audible clipping.  I'm guessing Helix falls into this category?   

 

The manual doesn't say if this is the case, only that the meter will display in red when the signal gets too hot.  Thing is, when my block flickers into the red, the meter bar below it still displays well with in the green range.  Not really concerned, just curious, because usually a manufacturer will state that visual red is simply an early warning.

[MartinDorr]

Whether you find a solid answer or not … why not just believe the meter telling you it clipped and fix your tone?

[boynigel]

On 4/9/2023 at 9:11 PM, MartinDorr said:

Whether you find a solid answer or not … why not just believe the meter telling you it clipped and fix your tone?

I neglected to mention in my post that i'm using LT in 4cm for effects only w/my amp.  Visual clipping only happens when i really slam the strings while on my amp's clean channel.  The other two channels don't clip because they're compressed as a result of being gained up w/preamp distortion.  but to answer your question:

 

1) my tone doesn't need "fixing"

2) there's no audible clipping

3) as stated, lots of gear makers design their gear for an early visual clip before actual audible clipping

4) as stated, i'm just curious if Helix does the "early warning" thing too, and just didn't note it in the manual

 

 

[DunedinDragon]

Regardless of whether you hear clipping or not, flashing red is not a good sign.  Intermittent flashing into yellow is understandable especially with signals that can be intermittently "peaky" like drums.  But you gain nothing with guitar signals peaking into red and are certainly inviting problems, so why not correct it?  The one certain thing is that any peak into red is telling you that you aren't getting an accurate digital to analog conversion.

[datacommando]

On 4/10/2023 at 2:01 AM, boynigel said:

visual red is simply an early warning.

As you spotted - the manual states:-

 

“For Send/Return - Send, Return, and FX Loop blocks - Whenever the signal level at any of these block types is too hot, a red fill color is displayed as a clip indicator. If clipping is indicated, you should reduce the signal level preceding and/or at the red indicated Send/Return block.”

 

It doesn’t mention anything along the lines of “it will give you a warning if you are getting close”, therefore you can ignore it, but it does clearly state - reduce the signal, because red shows it is too hot. Specifically - red means it has already happened, back off or use a limiter.

 

While driving do you ignore “red lights”?

Hope this helps/makes sense.

[PierM]

Probably you are expecting a different kind of clipping, more typical on analogue signals. Digital clipping is different and doesn't always produce distortion. In fact, it rarely does. Digital clipping means your signal transients are being "clipped", so everything above that line is being dropped. It can pop, or crackle, or just inject noise...whatever, isn't a good signal you are getting. The "trust your ears" isn't always completely true... ;) 

[boynigel]

On 4/10/2023 at 6:16 AM, datacommando said:

While driving do you ignore “red lights”?

Funny you should ask.  If nothing is coming in the other direction, yes, i blow right through.  One of the few perks of my line of work.  I don't get tickets.

[boynigel]

On 4/10/2023 at 7:00 AM, PierM said:

Digital clipping is different and doesn't always produce distortion. In fact, it rarely does.

It sure does in my DAW in those rare instances where something comes in too hot.   didn't know that it doesn't always though.  "the more you know!"

[craiganderton]

This is a more complex issue than it might seem. Due to their high resolution, digital devices have plenty of headroom. For example in Helix Native, you can go way into the red on the input or output and not introduce any distortion that's not in an effects block.

 

Where you run into problems is interfacing to the world outside digital processing. D/A and A/D converters have hard limits for how much audio they can handle without distortion. In this situation, you also need to be aware of intersample distortion. Most meters measure the actual values of the digital waveform’s samples, prior to reconstruction into analog. But that reconstruction process can create signal peaks that are higher than the samples themselves, and which don’t register on your meters. This is why DAWs have True Peak meters - they give a measurement of how high peaks will go after undergoing digital-to-analog conversion. (I doubt the metering in Helix is true peak, but with Line 6, you never know...)

 

For that reason, I always avoid going into the red to allow some headroom for intersample distortion. If you want to know more about this, check out Digital Metering Basics for an overview of digital metering, and scroll to the end for a summary of intersample distortion. For an explanation of how intersample distortion occurs, go to the article Why Is Normalization a Dirty Word?, and scroll down to the section that includes fig. 3. Hope this helps!

 

Disclaimer: This was written by a human being, not AI.