Allezvite - Not to get on a B&W discussion, but could you clarify how exactly the speakers you heard sounded "slow?" Did they sound out of phase? Not broken in? Just trying to understand. I've never listened to any other B&W products below the 800 line so I'm trying to imagine what you describe.
The Bryston/B&W combination always sounded very neutral to me. Not overly bright and the Bryston amps provide great clarity. I'll admit the B&Ws are high on the "bang for the buck" scale. Fortunately, I pu ...
Granted, a good question. My take on "slow" is this:
A "slow" speaker will tend to average out the dynamic peaks a bit, everything comes out sounding nice but not necessarily lively. The speed at which the woofers start and stop is definitely a consideration too. Some transducers seem to accelerate and stop quicker than others. This is both a function of electrical and mechanical design (efficiency, meaning how efficient is the transducer at translating voltage to pistonic motion, plus weight, materials, suspension etc.). That is why you seldom see 12" and 15", or 18" woofers in speakers any more, too much inertia. Most dynamic speakers use multiple small woofers to obtain the cone area as opposed to single large units (generally speaking).
This is also why so many audiophiles are enamoured with the large panel speakers like Martin Logan, Quad ESL, Magnepan that use lightweight materials and are capable of responding quicker to the demands of the music signal with real snap and fast attack compared to cone speakers.
The average music signal features transient attacks (especially rock, jazz and dance music) that may go from nothing to +50db in microseconds. Some speakers are better than others at responding to this electrical signal and translating it into cone motion and consequently the movement of air.
A slow speaker tends to lose out in bass articulation, and pitch definition (the ability to tell one note from another and when it starts and stops).
Some speakers seem to energize a room more dynamically with the musical transients (snare & bass drum sounds) than others do, responding with more agility to the dynamic peaks and valleys of the music signal.
My Dad's old Rogers speakers are positively sleepy. They are pleasant and neutral but not dynamic at all. Some speakers CAN sound boring.
The folks over at Linn refer to PRAT. Pace, Rhythm, Timing. Does the sound of the system move you? Can you follow the singer, the beat, the words etc. better on one speaker system vs. the other? Sure you can!
Some speakers get your feet tapping and pull you into the performance, and some are ho-hum, good for background music but not good enough to command your attention for any length of time.
If this is sounding very subjective, I apologize, but system pace and timing is a feature of audio performance that the British have known about for years that we North Americans are just catching up on.
There was nothing wrong with the CDM7's when I listened to them, in fact the midrange was very liquid and engaging. In comparison, it is well known that the PMC FB1's can sound a bit bright. However, in the bass department, the PMC's, which I would consider a "fast" speaker were able to sound more bouncy and responsive to the rhythmic pulses of the music than the B&W's.
My two cents. May the flames begin.
