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Phase Coherence or Time Alignment: Which More Imp?

This thread is really a follow on from a prior one that I let lapse. Thanks to everyone who contributed and helped me to better understand the importance of crossover design in building a loudspeaker. What I gathered from the last thread that there are opposing camps with different philosophies in crossover design. Leaving aside for a moment those that champion steep slope designs, my question is for those who have experience with speakers that are time aligned and/or phase coherent (using 1st order 6db per octave crossovers). Which is more important, phase coherence or time alignment? In other words, which more strongly influences the sound and performance of a loudspeaker? The reason I ask is because of the four speaker lines currently on my shortlist of floorstanders, three are either phase coherent or time aligned or both. The Wilson Benesch Curve's/ACT's and the Fried Studio 7 use 1st order crossovers but do not time align the drivers through the use of a slanted baffle. The Vandersteen 5's and the Quatro's both time align the drivers and use 1st order crossovers. I guess what I am asking is do you need to do both or is the real benefit in the crossover design? I'd appreciate your views.
BTW the other speaker is the Proac D25 and D38
dodgealum
skrivis
30 posts
 
The "X number of listeners thing it sounds swell" argument doesn't impress me because it also applies to Bose speakers...

"Professional" listeners? Like recording studio engineers or musicians?

I'm not sure I'd rate most studio engineers as a good recommendation for speakers. They often are listening for different things than the end user of the recording is.

I might respect a musician's opinion more, but I have no way of knowing whether they have actually compared "more correct" speakers to "steep slope" speakers, or whether they just find that Brand X "steep slope" speaker is better than a bunch of other incorrect speakers.

My opinion is that a speaker with steep slope crossovers doesn't stand much of a chance of being able to reassemble the original waveform at my listening position.

Whether that's important, and whether "time and phase coherent" speakers can reassemble the wave form correctly or not is where there's a lot of argument.

At that point I have to fall back on my own listening experience, and say that I feel that phase-coherent designs work better for me. They provide a better window into the recording.
skrivis
30 posts
 
That should have been "X number of listeners _think_ it sounds swell."
bigtee
803 posts
 
Skrivis, I was refering to major manufactures of well established companies. It is good to hear that Bud Fried's work is being carried on. I always had a ton of respect for him and was sorry to see his passing. Audio lost another great man. If I may quote something he said, "Someday, all speakers will be time and phase coherent." He truly believed in this concept.
I didn't want to say much about Pat McGinty because I really have no first hand knowledge other than he closed shop. I wouldn't think a man of his potential would stay down for whatever reason. I agree with you and would expect his return in the future. Lets hope so.
So far, in the time and phase camp, I have tried Meadowlark, Vandersteen and Thiel. I have really got to try Roy Johnson's designs out at some point. I also go back to listen to steep slope speakers from time to time to help keep my perspective. Now that my kids are out of college and out of the house, I have plenty of free time. It's nice to get back into enjoying the hobby again.
suits_me
121 posts
 
After this and other long, fact filled threads on the topic, we still don't know that Fried did not and doesn't make time aligned speakers.

He believed in first order series crossovers.

On that topic if Roy Johnson happens to read this: What about the higher order series crossovers like the Kaminsky? They claim phase coherence. Have you studied these? Thanks.
greenmountainaudio5317
8 posts
 
It has been a while. I recall seeing phase coherence but not time coherence. I did not pursue Kaminsky's work because it could only be implemented in an active crossover. Again, it has been many years, and I could be thinking of something or someone else. What I remember for certain about Kaminsky's work is that it was excellent, and it is worth examining again. Thank you for the reminder.

Series crossovers have advantages, and disadvantages. We use parallel circuits, which seem to have fewer disadvantages. I do not agree with statements like "better dynamic coupling of the drivers, using a series circuit", as I have never seen any definition of what that actually means.

Bud Fried made so many important contributions- he will be missed. The first speakers I heard that opened my ears in many, many ways were his original IMF transmission line speakers, in 1972.

Warmest regards, Bud. Thank you for everything.
Roy Johnson
Founder and Designer
Green Mountain Audio
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