Does Time alignment and Phase coherency make for a better loudspeaker?


Some designers strive for phase and time coherency.  Will it improve sound quality?

jeffvegas

^The subject of DSP is perhaps for another thread. But, as pertains to the subject at hand; DSP can be make available time and phase coherence to those that wouldn't otherwise have the considerable chop's necessary to accomplish it, and make it much less time consuming to develop and considerably reduce the labor costs to implement it.

It seemes to me, that if all else was equal, but one speaker was not time and phase alligned, and the other was, the one that was would sound better.

And I even have a bit of pretty strong evidence that this is the case.

The late Jeff Bagby, well respected speaker designer (professionally, and among DIY’s), designed 2 versions of the same speaker using the great SB Acoustics Sartori drivers.

The Kairos, which is time and phase alligned, and the Adelphos for those that are intimidated by building a cabinet with a slaneted baffle. There are also crossover differences, too, in order to compemsate for the flat vs slanted baffle.

Here are the kits and write ups:

Kairos

Adelphos

My friend and I built a set of both speakers, and compared. No question, the Kairos imaged better and created a bigger soundstage than the Adelphos. Other than those parameters, other aspects sounded, to our ears, identical.

And let me add, as with most well designed DIY speakers, the end result with both the Kairos and the Adelphos, are speakers that end up sounding as good as commercially available speakers at several times the money spent.

To my ears, I've never heard a better sounding pair of speakers than my Dunlavy SC-Vs. I started out with IIIs, then IVs, and finally my Vs. Once you hear proper time-aligned, phase-coherent speakers, and get used to them, you'll probably never want to go back to anything else.

I'd owned B&W 802 S3s for 18 years before I bought my SC-IIIs in late-summer 2019, and it took a little while for my ears/brain to get used to what I was hearing on the Dunlavy's. Once I got used to the Dunlavy 'sound' I couldn't go back to the B&Ws. The IVs were even better than the IIIs, especially in the bass, and the Vs are an bigger improvement over the IVs, than the IVs were over the IIIs. 

The Dunlavy's are incredibly accurate speakers; but they can be brutally honest on bad recordings. They don't have any colorations, so if you're used to a certain type of sound that isn't incredibly neutral then you may not like them.

 

I agree with Millercarbon. Phase and tme alignment is critically important, but when it compromises other aspects, then you will get a less than desirable effect.

BTW, absolute phase and time alignment is IMPOSSIBLE to achive for the entire spectrum of 20Hz-20kHz. Phase correct means only that the crossover regions are not out of phase.

Time alignment also applies only to limited frequency ranges... 

Nevbertheless, when a manufacturer is aware of these parameters, and stirves not to make blatant errors in these areas, it does make for vastly better speakers compared to those where the manufacturer is unaware of these issues.

;

actually phase accuracy in the rest of the chain is difficult and requires an engineer with ears deeply involved in the listening and design process... Charlie at Ayre comes to mind... No global negative feedback.... think thru what NFB is, how it works and what positive and negative aspects it can have.... Of course we owe Dr Otalla a debt of thanks for derailing the THD crowd.... The T in TIM is all about time... ( a quiz of sorts ). I have a variable NFB amp ( RIP Roger, you were a genius )... Assuming level matching, the changes to stereo image across various NFB is apparent.

Carry on ! enjoy the music.