John Curl's Blowtorch preamplifier part II

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Esperado said:
Yes it is. As you confirmed. Measure the LF ringing of your arm resonance. Set an analog active notch filter with the same resonance frequency and Q. Flat response curve, 0 group delay there.
Yes........BUT you then need a filter with the following freq and (minimum) phase response (see attached plot).

And the problem a decade below the resonant frequency is obvious, +40dB gain at c 1Hz......just don't slam the door !

(Reposted, including the attachment this time )
 

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Lucky thanks for both posts.
But I do find this 'pre-ringing causality-violation' misleading. The pre-ringing does not occur in real time before the impulse that causes it.
Jan

If I process a signal to play tomorrow, causality in the extremely literal sense can not be violated, but it has to be clear by now how unnatural the results of linear phase filters can be.
 
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Reduce reflections -

If you want to hear anything remotely accurate to the source, you need to be in the direct and not reverberant sound field; You can do this by siting closer, deadening the early reflections and/or a more directional source or headphones. Phase or GD and many other things are obliterated by a lot of reflections.

View attachment GD and reverb.pdf


View attachment Phase and GD.pdf


THx-RNMarsh
 
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Richard,
At the same time all those things are the norm, we are use to listening in reverberant situations. The only unnatural thing are the headphones, that is never correct, it just is far from a natural hearing environment.

That may be true for you.... but it is not true for me. I have followed the LEDE and similar practices for decades. I do not sit in the reverb field. You can measure where it begins in the room. Remember, I am only interested in getting the best results....Hi-End... not the typical... speakers at one end of the room and listener at the other end for a listening arrangement.

If you look at S.Linkwitz listening room.... a very reverb room (glass walls on both sides etc) and he sits in the middle.... thus he needs a more directional speaker to receive clarity to the source.

I attached a couple pages about how reverb affects the sound rel to phase and GD. Pls read. Or better, buy the book and read all of it.

THx-RNMarsh
 
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Richard,
If as it appears you are attempting to reproduce a recording studios acoustics that is fine with me, most people don't have that option. At the same time you would need to use a soffit mounted system to truly get that right if you are attempting to reproduce what an engineer in a studio was listening to.

My point was on the headphones, I don't care what you have, they are never going to be correct for playback, never going to happen with one ear isolated from the other. I don't want to hear about bin-aural recordings, not enough to even consider that option.
 
That may be true for you.... but it is not true for me. I have followed the LEDE and similar practices for decades. I do not sit in the reverb field. You can measure where it begins in the room. Remember, I am only interested in getting the best results....Hi-End... not the typical... speakers at one end of the room and listener at the other end for a listening arrangement.

If you look at S.Linkwitz listening room.... a very reverb room (glass walls on both sides etc) and he sits in the middle.... thus he needs a more directional speaker to receive clarity to the source.
My experience is that if you get the quality of the sound being output by the drivers sufficiently good, as in, low enough in certain sorts of artifacts, then all this sort of carry on is unnecessary. I've had systems working in the worst sort of rooms, totally wrong from the usual perspective - and it doesn't make the slightest difference to the perceived quality. Reason is, that the ear/brain has enough good information being fed to it to properly decode what's going on - and 'convincing' sound is automatically switched on, inside the brain, without you having to do anything special to cause that switch to flick over.

Clarity to what's happening inside the reproduced event is part of that package, it's just there, all the time, irrespective of how you concentrate, or don't; and where you are in the listening environment.
 
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