looks like "There is no free lunch"?
I thought 40kHz with a "noarmal" 48dB per octave filter will take care of it... what if the filter would be at 22khz?
Btw. what i reference to as normal analog like filter is called "minimum phase filter" or iir?
Is there a way to completely avoid pre echo and if so whats the compromise?
This paper sounds like a good reference for this topic? (i have not bought it)
https://www.aes.org/e-lib/browse.cfm?elib=17497
I'm not going to comment on that paper.
When you set a transition band on a filter, that determines, effectively, the impulse response length (even if it's an analog filter, via storage in the filter components). What you don't determine immediately is the phase characteristics.
Now, by going from minimum phase (all poles and zeros inside the unit circle/left half plane) you can trade off phase shift and/or group delay (same thing expressed in different ways) for total delay (flat delay at all frequencies) which gets you to "linear phase" (better described as "constant delay"). Such filters are FIR only. There is no "constant delay" filter in any IIR design, that would require infinite delay and poles outside the unit circle. Good luck with all that. Now, one can approach that (with a lot of effort) by using allpass sections to correct for the delay, but you're still bound by the issue that a precise elimination of phase shift (in favor of delay) requires infinite time.
A constant delay filter is either symmetric or (if it has a zero at DC) antisymmetric. So it has substantial pre-ringing, but the magnitude of that is controlled by the length of the filter, the in-band ripple, and the width of the transition band.
So, what's better? Good question. Some people go for a "partially minimum phase filter", some insist in constant delay, a few insist on minimum phase.
There needs to be more work done on the testing of audibilty of such. This is an absolute (*&(*&(*&&* of a test to run. Pretty much, you need 10 year old trained listeners to have any hope of hearing anything.
IIR filters by definition have minimum phase poles, otherwise they would be either uncontrollable (on the unit circle) or unstable (outside the unit circle). (For analog filters substitute "wrong half-plane". IIR filters by nature can never be perfect constant delay.
FIR filters can be anything. They are usually designed as 'constant delay' but there is absolutely no reason that they can ONLY be constant delay. You can make one minimum phase, maximum phase, whatever you want, since they only have zeros.
(Sorry, just noticed you also asked that question.)
So, here's another slide deck to peruse:
https://www.aes-media.org/sections/pnw/ppt/jj/filtutv1.ppt
That is very, very old. Maybe it's time I do that again, and have the talk recorded?