High Sensitvity = good transient response ?

Twl, about the 40 Hz rating. I've heard Brentworth single driver with Waytec SET (20 Hz rated) and the bass was disappointing.
Am I missing something because, take B&W Nautilus 804's for example,are rated at about 40 Hz but they seem to have more weight than the 20 Hz rated single driver? Is this a dynamics issue?

Hi twl. I heard the $7,500 Type Three-A:
http://www.cadencebuilding.com/cadence/bslpix.html
The owner had the best Waytec SET amps and they are supposedly made especially for the Brentworths. I think they were over $8,000.
The room was very big - 18 feet wide x 28 feet deep (guess) so there was no room boundary reinforcement. Maybe sonic treated as well.
Listening in the nearfield these speakers are very clear. Piano was notably richer, fuller than SS gear. Had the distorted immediacy SET's are known for. I heard SET don't do deep bass and maybe with SS amp there would be more bass.
As my girlfriend said, it was all one level. Meaning there were no real highs and no real lows. Also no big dynamics you get with cone drivers. You probably know all this.
I didn't do the test frequencies but bass seemed to be running out around 70 Hz as a very loose guess. That seems really high but I just wasn't getting the base in organ music or the power in bass guitar.
These speakers had the most incredible soundstage I have ever heard. Neil Young live recordings finally made sense. On every speaker I have ever auditioned since, when I play "Needle and the Damage Done" Neil Young is pushed up above the audience. With the Brentworths, he was 20-30 feet away and the audience was understandably located around him. I didn't appreciate this feature until I could never duplicate it again. I thought Audio Physics could after hearing the Step ($3,500 model) a while back but no, the Virgo III's couldn't begin to compare. Maybe Audio Physic lost this feature because the Step's had to-the-inch listener position sensitivity and the Virgo III's sure didn't.
Hearing Michael Jackson's half speed master LP Thriller again had amazing depth and the footsteps were fast but had the SET pleasant distorted sound. This is how records should sound.
I'm not sure what else to say. They weren't for me because I like punchy, full range, dynamic sound and trying to analyze why he bought them, I guess he wants a stereo he can go home and relax with. Also he said the Audio Physics couldn't do the sounstage like the Brentworths.

Twl, on SET sound. I've been told they have high amounts of distortion so maybe what I've been told affects my hearing perceptions. Take "Spanish Harlem". The first time I heard on Triangle Celius and Unison SET Rebecca Pidgeon's voice sounded vaguely like if you talk through fan blades while the fan is running. Sort of funny but nice. After a short time I forgot about the "funny" sound and enjoyed the music.
You are right about Lowther being more dynamic. Brenworth's, being planars, vs. Lowthers would probably be like Martin Logan vs B&W in the dynamics department.
I heard some single driver Lowther at HE2002 and they seemed more dynamic and extending than the Brenworths. But I heard some peakiness or unpleasant edginess especially on the piano pieces played and that turned me off. Brentworth's don't do this. Sorry, I find fault in everything. But it beats the "weaknesses: none" response that pops up a lot.

Learn something new everyday. And I thought that the covering on Brentworth's opening was the driver. I have only heard 2 SET as dealers don't carry this stuff. Sam Tellig talked with Mike Sanders re Quicksilver Mini Monos / March 2001. Page 36 I quote:
"The distortion is so high with Single-ended that when you put negative feedback around it, you get distortion of distortion. . . The distortion is multiplied so the amplifier sounds worse"
"The annoying thing is the higher distortion, because you don't get the distortion cancellation that you do with push pull. . . So you can't get rid of the distortion of single-ended with feedback: after a while, that distortion just eats away at you".
This is about all I know about SET.
I've only been in this hobby 1 year. Sometimes I think I should've gotten another boom box :)
Went to 2 live shows last month and the musicians and singer were playing through mics / amplifiers / speakers and even though their systems really did have a lot of distortion compared to audiophile stuff somehow it was better. Seemed like that "immediacy" thing people talk about with SET. So I'm interested in SET stuff.

Those were Mike Sander's (Quicksilver Audio Mini Monos)) quotes, not Sam Telligs'. Mike also said:
"The push-pull had more top end extension, more bass extension, and sounded more solid and controlled. But the single ended had a fastness and a clarity, a purity, and a level of detail that teh push-pull configuration didn't have".
Maybe this is why the SET driven Brentworths had less bass. The guy who owned them did agree that they sounded "different" from other speakers and you had to get adjusted to the sound.