sharke
 
Some time ago I noticed that simply engaging the HPF of the Quadcurve EQ was sometimes enough to "overheat" a ProChannel signal (i.e. whereas before the ProChannel clipping light was not showing red at any point during playback, engaging the HPF would make it glow red in a few places). I know there has been a lot of talk in the past about what those ProChannel clip lights actually mean in reality, but what this did make me realize that as Frindle says, rolling off the lows with a filter can actually increase the peak level even though you're losing frequencies. I always found that interesting. 

Any time you engage an EQ there is phase shift involved, which can cause a change in peaks. 
 
Sometimes it's not really helpful to get too caught up in the often complicated technical details. It can be very difficult or almost impossible to simplify technical things too much without saying something misleading or inaccurate. And if someone makes an even remotely questionable technical claim it invites a response even if it's not particularly relevant to the discussion at hand. If I remember correctly, Frindle got himself in trouble in that thread by making some technical arguments that weren't really in any way germane to the point he was trying to make, but invited a long technical debate nevertheless.

John T

sharke

 

Some time ago I noticed that simply engaging the HPF of the Quadcurve EQ was sometimes enough to "overheat" a ProChannel signal (i.e. whereas before the ProChannel clipping light was not showing red at any point during playback, engaging the HPF would make it glow red in a few places). I know there has been a lot of talk in the past about what those ProChannel clip lights actually mean in reality, but what this did make me realize that as Frindle says, rolling off the lows with a filter can actually increase the peak level even though you're losing frequencies. I always found that interesting. 

That's a normal property of a low or high pass filter. Basically, the neat shapes you see in the graph are a bit of a lie, really. There's always some sort of resonant boost around the cut-off frequency.

Has nothing to do with any resonance. Simply speaking, the low frequency oscillation you're cutting has a positive and negative side on the amplitude graph. It could be that it is actually inhibiting a peak on the positive side because it is itself peaking or near peaking on the negative side. This is true even for non-resonant linear phase filters. It doesn't go just for low frequencies but a HPF often cuts a significant amount of a high energy frequency area so it's relatively common there. Another reason not to send files off to mastering at near 0dBFS.

Ah, interesting. I've clearly misunderstood something somewhere.
 
This may appal the more technically-minded, of course, but I'm happy that my rule of thumb of "cuts in a filter may cause increases in level" was basically right, even if I was wrong about why. It all comes back to the larger point in the discussion which is "stop mixing close to 0db and a lot of these issues just go away".

No one can design a digital meter to truly interpret a DAC's response to saturation without feedback from the DAC. But anyone can design a meter to measure the grouping of saturated samples and market it as a tool.
 
Inter-sample peaks seem to get a bad rap on the web.
 
DACs are designed to minimize saturation effects. The result of this design is currently being referred to on the web as inter-sample peaks. It is not a bad thing it is a good thing. Not sure why on the web two saturated samples are referred to as distortion. It would only become distortion e.g. DC with a grouping of saturated samples that exceeded the DAC's design specification to minimize saturation effect.
 
That aside imho there is very little to gain in saturating a DAC.
 
A design engineer would assume that if you intentionally saturated a DAC your intent was to do so in order to make use of the saturation effect.
 
If it is used as a tool for you to reach some end then that is what it is. When you speaker coils glow red you have gone to far.

If you are saturating a DAC within the guidelines of the DAC's specification to minimize saturation effect then for all intents and purposes your objective is to deviate from optimal reconstruction for the sake of SPL. Under this scenario imho it would be an available tool if that is your goal and you can control the saturation to remain within the DAC's established boundaries. afik at this point in time this would require a significant amount of work on the part of the person attempting to accomplish this.

Freeze all your tracks (the snowflake * symbol). Now try again.
 
Do the peaks still clip in a different way depending on where you start?

...oh, and for the test, also turn off the FX bins in any busses you might have.