Loudspeaker sensitivity and dynamics: are the two inexorably linked?

I would agree with our op on this topic. dynamic impact helps recreate detail that in turn fills the soundstage that pulls me into the music. That said adding power and dynamic headroom to less sensitive speakers can balance things out and considering high sensitivity speakers often sacrifice low bass to get those high numbers sometimes it's worth the investment in source instead of integrating a subwoofer.

steve59 wrote:

... adding power and dynamic headroom to less sensitive speakers can balance things out

Depending on the particular speakers you don't just "free-meal" add dynamic headroom with more power when sensitivity sits in the low end. Lack of sensitivity is the main culprit here, and more power will only get you so far until thermal compression/"modulation" sets in and becomes a negative factor. Usually inefficient speakers don't compensensate with more power handling - rather to the contrary compared to pro segment, and much more efficient drivers - and so the issue is really made all the more worse. 

In any case having prodigious power and/or otherwise efficient use of it, like with active configuration, is a good thing, and will certainly maximize the potential of a given speaker system macro dynamically - not least with high quality, higher power handling drivers - compared to a more anemic, inefficient power delivery when passive filters are involved. 

... and considering high sensitivity speakers often sacrifice low bass to get those high numbers sometimes it's worth the investment in source instead of integrating a subwoofer.

Unlike low sensitivity and the inherent, practical limitations with headroom here, high sensitivity and low end extension aren't mutually exclusive but rather a matter of proper sizing (so, in this case you actually have your cake and eat it too). That is, high sensitivity capable speakers are typically attenuated quite a lot of dB's with resistors in a passive, horn-loaded mids and tweeter section to meet their lesser sensitive and direct radiating woofer counterpart, and this is not without implications, both with regard to overall coherency and getting the most out of the horn-loaded sections (another reason to go active here and/or all-in with size).

When the system sensitivity in the rarer cases approaches or even, very rarely, slightly exceeds 100dB's with horn-loading it usually means a some 35Hz cut-off at the lowest with stand-alone main speakers. Listening to the bass of such a system however, like the Khorns, is certainly - by a wide margin - the preferred sonic scenario to my ears, also when factoring in a by-specs relatively limited low end extension; honest 35Hz gets you a long way in most cases, and reproduced via more unadulterated, higher sensitivity bass sections will come off feeling even deeper and more convincing. As it stands though few a willing to let size have its say..

phusis, 

I don't believe my typical boxes will match the spl or dynamic capability of a lascala or K horn by adding a couple 2 kilowatt monoblocks to them, only that adding headroom helps bridge the gap. I had a really close friend that wanted to sell me his LaScala's when he bought the K-horns, but while being dynamic they didn't really appeal to me. different strokes I guess.  The K-horns sounded much different and to my ears much better.

steve59 wrote:

I don’t believe my typical boxes will match the spl or dynamic capability of a lascala or K horn by adding a couple 2 kilowatt monoblocks to them, only that adding headroom helps bridge the gap.

This may come down to semantics, but "adding headroom" - unless a given pair of low. efficiency speakers are under- and/or inefficiently powered - requires of the root of the problem, i.e.: the low. eff. speakers themselves with a fixed and usually moderate power handling, to be replaced by a more eff. and potentially higher power handling speaker solution, assuming of course it’s properly powered.

Again, there is only so much that can be asked of a low eff. speaker package macro dynamically before thermal and mechanical issues become prevalent, but having an abundance of clean power to feed it will certainly maximize its SPL envelope - to a degree, and within the limitations of the design.

I had a really close friend that wanted to sell me his LaScala’s when he bought the K-horns, but while being dynamic they didn’t really appeal to me. different strokes I guess. The K-horns sounded much different and to my ears much better.

I much prefer the K-horns as well, both due to the more properly sized (but still too small) bass horn when factoring in the effective extension of the horn when corner mounted and assisted, as well as the higher and vertically placed mids and tweeter horn sections. The corner mounting emulates a non-truncated horn loading by way of the horn extension via the walls (the K-horn bass section itself is truncated), but there are still throat constrictions that causes the colorations heard in the upper bass and lower mids area. Being as it may the K-horns are still the much preferred outcome sonically compared to the LaScala’s, with a fuller, better scaled and more realistic overall presentation.

Further nitpicks: I’ve only heard the latest iteration of th K-horns (AK6) and found it too tipped up/coarse in the tweeter range, and while the mids sounded fine and open overall it veered towards a slightly lean character and with a hint of horn material resonance. Maybe finding an older, used pair of K-horns and replace the mids and tweeter sections with an upgrade kit provided by Greg Roberts (of Volti Audio) that incorporate more solid wood mids and tweeter horns with B&C drivers (most notably the DCM50 midrange compression driver) and upgraded crossovers would be the ideal scenario. I previously owned the Simon Mears Audio Uccello’s, which are an homage to the Klipsch Belle, that featured stacked ply Tractrix horns, named B&C mids and DE10 tweeter + modified Al Klappenberger crossovers, and they sounded lovely - way better in the mids and tweeter range compared to the orig. LaScala’s. The bass horns however were essentially similar and therefore marred by the same issues, apart from the height restriction of the horizontally mounted mids and tweeter section mentioned earlier.

Anyway, "bridging" the mids/tweeter section from B&C w/wooden horns with the bass horn section of the K-horns would be the best marriage and really lift the overall performance here. Worth considering.

P.S.: What would really be interesting with the K-horns, on top of the suggestions made above, would be stripping them of their passive crossovers and convert them to outboard active configuration. This way more of their inherent issues could be addressed, but that’s for another post/thread.

If electronics slew rate is a limiting factor, obviously the more sensitive speaker is at an advantage because the equipment doesn't have to slew as many volts to reach the same volume level.  Assuming the same electronics (amp), the slew rate is directly proportional to the required voltage.