[randkyp]

Any way to set pre-amp to avoid clipping or is there built-in headroom / automatic gain adjust so that that is taken care of by default?

[keurrr]

So my background is I did music production in high school. I actually based the design for PrettyEQ off of the Logic Pro X equalizer and Fruity Parametric EQ 2, and those will happily let you clip. So I like the idea of leaving that to the user's discretion (move the filters slowly, especially in the lows and highs, and know your speakers well). These days, especially in EDM / Hip Hop, slight clipping in bass in somewhat stylistic. So I don't know. Maybe could be an option in the GUI that could be switched on? Would need to think about it more.

[ldarby]

> These days, especially in EDM / Hip Hop, slight clipping in bass in somewhat stylistic.

No it's not, it's just widespread incompetence and has ruined lots of music I would have liked. Having better software tools that alert when clipping is happening would be a good thing (i.e. it needs to alert when crossing over from 0dB to a distorted wave form, not just hitting 0dB without distorting, which is fine).

[qmmmur]

You know you can distort without clipping and can clip without blowing out your meters?

[ldarby]

> clip without blowing out your meters

If the audio clips, and the meter doesn't "blow out", then in my opinion that is a defective meter.

ALSA already has an eq plugin (http://quitte.de/dsp/caps.html#Eq10) and I added this to it:

                if ((s > +0.99 && x[z1] > +0.99 && x[z2] > +0.99) ||
                    (s < -0.99 && x[z1] < -0.99 && x[z2] < -0.99) ) {
                        //clipped audio isn't exactly 1.
                        printf ("dsp/Eq.h:process(): input clipped :(\n");
                }

....

                if (
                    (r >= 1.0 || r <= -1.0) &&
                    (r < 20 && r > -20)) { //uninited memory?
                        printf ("dsp/Eq.h:process(): output clipped :( %0.16f\n", r);
                }

(one day I should try to get upstream to accept that or something like it...)

[keurrr]

If you feel strongly about clipping, I would also accept a patch that allows a user to select an option in the GUI to prevent it.

[ldarby]

Yes, I have strong feelings about clipping... For many years I was using the track Moby - Inside trying to find a hifi system or headphones that could play it without sounding crap, then discovered it couldn't be because it's clipped.

And thanks but I'm happily using my patch on a pure alsa system without pulse audio, and don't really have the time to spend on adding the equivalent to yours sorry. But I'd want to if only to spread awareness about clipping - it's not just music, there are also many Youtube channels that I unsubed from because of it (I did tell them but they didn't care).

Actually preventing clipping instead just detecting it (which mine does) is a lot of work - it would need to find the loudest frequency, then find the closest band and reduce that (while loudly informing the user, and oviously with an option to control it).

[randkyp]

If the equalization is done near the end of the audio output chain (ex: music player, defaults at 100% volume -> user sets master audio output volume to 50% -> EQ is applied) then a pre-amp is not strictly necessary if the EQ can take advantage of the extra headroom in the output channel. Otherwise, an adjustable pre-amp / gain setting would be nice, preferable with the option for it to automatically set itself to reduce by the maximum gain the EQ is applying to avoid clipping. But yeah, it should be optional; if the user wants stuff to clip, let it clip.