Best speaker brands for transient response

Years ago I tried to measure transient response to come up with an understanding of why I thought horns sounded better than direct radiators. In nearfield measurements I was shocked to see that cheap little bookshelf speakers that only sounded OK to me were actually faster and cleaner in the transients than my beloved horns, which were a bit messy because of ringing. I was looking for extremely high speed effects at the start and stop of notes at all frequencies, and what I learned is that my perception is far less effected by those than longer term effects of room reflections. My conclusion was that my perception of dynamics and speed from the horns involved time periods of 5 to 10 milliseconds or more - issues that arise from room reflections, not sub 1/10th millisecond issues that arise from the mass of the diaphragm, or slew times of amplifiers, or differences in arrival time between drivers. The improved direct to reflected ratio from the horns higher directivity, I concluded, was what was giving me the impression of horns being faster. I deduced this was also somewhat true for electrostatics and other dipole designs that tend to cancel along their sides, so the direct to reflected energy is higher at the listening position. I’m still not certain of this, because I have found ways to make horns sound really tame and seemingly lacking in dynamics, so a balance of frequency response is also important. Insufficient energy in the midrange, and other frequency response imbalances also seem to kill my impression of impact and speed. So a well balanced direct radiator may in some ways seem to hit harder.

Also the ability to turn up the volume without apparent strain on the system seems quite important.

This may not be true for everybody, so I’m not saying this is THE answer, but it’s an answer that at least partially explains what some of us our hearing that correlates to our perception of quick dynamics. I have heard plasma tweeters on various occasions, and they sounded good to me. But I’ve also heard little 3/4" doped silk dome tweeters sound every bit as fast. It always amazes me that a little soft piece of silk with rubbery goo on it can sound like a high pitched metal bell when asked to.

@terry9 My experience of slew rates is different. I am driving ESL's, and my amps sound good with 30V/us output transistors, better with 40V/us, and better yet with 50 V/us; that is, better transient response.

Interesting. Reading up on slew rates, it seems a higher slew rate results in more power capacity at higher frequencies. So you may be hearing extended linear      high frequency response, and that definitely is a type of transient response. My hearing doesn't extend up as high as it used to. I think I stop somewhere around 15kHz.

Something new to me about slew rate and horns - higher efficiency speakers can do what a lower efficiency speaker would require a higher slew rate from the amplifier to do. So low efficiency combined with a desire to play loud creates a requirement for a higher slew rate, assuming you don't want the high frequencies to roll off. Also, I learned that a high slew rate if not implemented carefully can come with overshoot and ringing that can also make for a "faster" sort of sound, but generally not thought to be in a good way.