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First order/Time Phase-Coherent speakers discussions

"The game is done! I’ve won! I’ve won!"


I would like to use this thread to talk about this subject which I find rather fascinating and somewhat difficult to get my hands on. I went through a course in electromagnetism in college and I have to say this is even more confusing and you won’t find the answer in calculus, physics, Einstein relativity be damned it’s not in there either and definitely not in quantum physics. Listening to the "experts" from Vandersteens and Stereophile but ultimately it all came down to a missing link sort of argument ... something like this:
"Since if a speaker can produce a step response correctly, therefore it is time-phase coherent, and therefore it must be "good".

It’s like saying humans come from chimps since they share 90% genetic content with us, but we can’t find any missing links or evidence. FYI, we share a lot of gene with the corn plants as well. Another argument I’ve heard from John Atkinson that lacks any supporting evidence and he said that if everything else being equal, time-phase coherence tends to produce a more coherent and superior soundstage, but to the best of my knowledge, nobody has been able to produce some semblance of evidence since there is no way to compare apples to apples. Speaker "A" may have better soundstage simply because it’s a BETTER design, and the claim "time-phase coherent" is just a red herring. There’s no way one can say the "goodness" from "time-phase coherence" because you can’t compare apples to apples. Ultimately it’s a subjective quantification.

I’ve been doing some simulation and I will post some of my findings with graphs, plots, actual simulation runs so that we are discussing on subjective personal opinions. Some of my findings actually shows that intentionally making time-phase may result in inferior phase problem and NOT better! (will be discussed more in detail).

Having said all that, I am actually in favor of first order/time-phase coherent if POSSIBLE. I am not in favor of time-phase coherence just for the sake of it. It’s just that there are a lot of mis-information out there that hopefully this will clear those out. Well hopefully ...

Here my preliminary outline:

1. My "subjective" impression of what is "musicality" and how it’s related to first order filters.
2. Interpretation of step-response. I’ve read a lot of online writing with regard to the interpretations but I think a lot of them are wrong. A proper interpretation is presented with graphs and simulations.
3. A simulation of an 1st order and higher order filters with ideal drivers and why time-phase coherence is only possible with 1st order filter. This part will use ideal drivers. The next part will use real world drivers.
4. A simulation with actual drivers and how to design a 1st order/time phase coherent speaker. Discuss pros and cons. And why time-phase coherence may actually have phase issues.
5. Discuss real world examples of time-phase coherence with Thiel’s and Vandersteens speakers (and why I suspect they may not ultimately be time-phase coherent in the strictest sense).
6. I’ll think of something real to say here ... :-)
andy2
andy2 OP
1,548 posts
 
Ivan Ivan come out where ever you are lols.  Are you hiding in my closet lols.
ivan_nosnibor's avatar
ivan_nosnibor
1,047 posts
 
The way you treated me I could expect, my problem was with the way you treated everyone else here.

Like about everyone else in this thread before me has figured out and gone (where are they now), you're long on making a splash and short on contributing anything useful. There were plenty useful comments here to make a good thread out of, but you were only interested in what you think you know, as others tried to tell you.

But, for everyone here and any exchange of ideas, you were too much of a headache and too much of a PITA...I'll leave it to you as to how that pairs up.

I think I'm out.
andy2 OP
1,548 posts
 
I think I'm out
Yeah, why don't you're out of this universe if you know what I mean.  Some how I doubt it.  I'll probably have to deal with your shenanigans sooner or later.  


ivan_nosnibor's avatar
ivan_nosnibor
1,047 posts
 
Look, I'm not out to dog you to hell and back. I'm not asking you to change your style or anything...just try to be just a Little more respectful of everyone else's point of view...maybe even if you don't entirely agree...maybe offer a civil but rational response that might explain your objections in the terms they presented??…just a little more give and take maybe?? 

That's all I'm trying to say.
whitestix
709 posts
 
Timlub,
I appreciate you sharing your knowledge on this vexing aspect of audio.  I can't say I understood it all, but it greatly aided my background on the topic.  

Roy at Green Mountain Audio was a big proponent of time alignment of the drivers in this speakers.  He also advocated removing ones eye glasses when listening to speakers because of the "smear" ? that they  caused in aural perception.  I built a pair of Linkwitz LXmini's a few years ago, before they came out with the companion subs for them and they were pretty sublime, but rendered my expensive 2-channel amps unusable and had limited LF response.  

I remember in 1983 when bought a pair of Spice TC50's.  I was casually listening to them one night when my neck and attention snapped to the left of the room when some violins started playing on the track... the imaging was simply unbelievable, palpably realistic.  At the time I listened to music at pretty high SPL's and went through several woofers and tweeters before moving on to JSE Infinite Slope speakers from Jeff Joseph.  They imagined quite well too, but not like the Spica's.  The Spica's were like electrostatics with a very narrow sweet spot.  
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