Why do only US makers focus on time coherency?

That's a very good question. The british speakers seem to be more interested in smooth frequency response, than time and phase. To date I haven't heard a british speaker that images particularly well (and don't say ls3/5 because they don't image at all !)

As a brit myself I find my compatriots' fascination with this thing called PRAT to be a bit odd. Why are we so quick to throw out spatial information to try to make the music bouncy ? Perhaps because fewer brits have the space in their houses to allow for speaker positioning that would allow imaging ?

Hammy .. Pace Rhythm And Timing. It's about whether a stereo makes you want to tap your foot or go to sleep.

Why do some companies discount it? My guess is because time and phase correctness and first order crossovers place constraints on the drivers (must operate in much larger ranges) and this can lead to reducing the power handling and dynamics of the speakers.

How many times have you heard of a spica or dunlavy owner blowing a tweeter ... quite a few. My guess is that it's not unrelated to the coherency of the speakers. How many time aligned speakers produce good solid bass ?

I prefer accurate to loud so it's a trade-off I can live with. Plus by adding a powered sub I lose coherency only in the lower octaves, where it doesn't matter so much.

The other thought is that so many speakers are placed suboptimally for imaging (the principle benefit of coherent designs) that many owners will simply never appreciate it. I'd bet over 90% of high end speakers sold are never correctly placed in the room for optimal sound, due to ignorance, decor, WAF etc.

For example if you put my spicas close up to the rear wall they sound pretty awful ... so many buyers would assume they're bad speakers. B&Ws, Harbeths, and other non-coherent speakers would probably sound much much better in that placement, leading the buyer to assume (erroneously) that they were much better speakers.

I guess what I'm saying is that the market for coherent speakers is probably narrowly focued on hifi nerds like myself, who organise the room around the stereo, rather than vice-versa. You don't get to be the size of B&W by pandering to our needs.

Can someone give me an example of a speaker that images as well as or better than the spicas that is not coherent (spica's aren't coherent, but do a reasonable approximation).

Perhaps I'm completely wrong for associating imaging with phase and time coherency ? After all in the studio mixing and mastering I can't believe that all the "aural exciters", compressors, limiters etc etc are time coherent ... so the CD / LP already has phase and time errors at the source ?

I've heard it said that a narrow baffle reduces diffration and improves imaging, but the baffles on the spicas are nearly 2 feet wide around the tweeter !!

I've heard it claimed that concentric woof/tweet improves imaging, but my spicas image much much better than some kef 103/4 reference speakers that use the concentric design.

I've heard it said that small stand-mounters image better than large speakers, but the spicas just killed a borrowed pair of Spendor s3/5s in the imaging department (well in just about every department).

So what exactly does determine if the imaging thing happens ?

(My europas arrive on Friday .. I will post a review comparing them to the spicas in a month or so. I don't change equipment often, nor do I frequent shops or shows, so I can't compare more widely ... but the spica angelus sets a high benchmark for realistic live music reproduction above 100Hz.)

Oh, and I wasn't bashing B&W .. horses for courses ... I've never heard a better rendition of AC/DCs "Bullet to bite on" than through DM603s ... very grin inducing !

It is my (admittedly very limited) understanding that electrostatics are coherent. I remember hearing some large Martin Logans at a dealer in the UK and being impressed that the soundstage was incredibly wide. However the imaging was very diffuse within the soundstage ... nowhere near as pinpoint as my spicas.

Of coure there are those that say you never get imaging so precise in real live performances ... I assume that they must only have one ear in the middle of their foreheads :-)

(Remember the joke about Davy Crockett's three ears ... left ear, right ear and wild front ear ?)

Bombaywalla ... I heard the DM603s and the imaging was far below that of the Spicas, though they had much better dynamics. When I heard reviewers say that ls3/5s image well I wonder if the same reviewers ever heard tc-50s or angelus, because the ls3/5s are not in the same league.

Bomarc ... agree the proof is in the listening. That said I'm just musing as to why the spicas do the spatial thing so much better than all other comparably priced speakers. Since all spica speakers have this attribute it's not coincidence ... some aspect of Jon Bau's design directly created it, and I suspect it is attention to the time domain response.