Am I the first Harbeth (x2) owner to respond?
The SHL5+ use a tweeter, super-tweeter and the 8" Radial 2 mid-bass driver. It is very neutral and versatile and can be driven very nicely by a cheap 50w amplifier. For a time I used a 35w triode valve amp. Push them with some more power (say a Quad 909 for £500) and they have a remarkably good bass GIVEN THEY ONLY HAVE A MID-BASS.
They do not employ bass enhancement like PMC's ATL (I changed from PMC Fact.8 to SHL5+). If you want big bass they make the M40.2 that are a quite astonishing speaker. I have heard them at a 3-hour demo and consider them vastly more musical and refined than, for example, PMC MB2 SE, which are almost twice as expensive.
However, if bass is what you want then the PMC MB2 SE is probably for you.
The real joy of Harbeth is actually the low volume performance, where my PMC's fell down (and they cost twice as much as the SHL5+). The dynamics achieved at low listening levels are astonishing, so I don't find myself cranking up the volume unnecessarily.
At the M40.2 demo Alan Shaw started with half a dozen piano recordings (at progressively greater recording distances), several BBC voice recordings, then a nice mix of pop music, jazz, highly percussive music and so on.
It is very unfortunate that the dealer used a poor playlist and possibly an under-powered amp.
I hear what you're saying, but I'm evaluating under different optics or with a different viewpoint.
I hardly ever, if ever, rate the 'treble/mid/bass' of a system as components other than at the window-dressing stage. I don't care really how limited the bass response is either in a chart or in reality unless it's SO limited that you're feeling like you're missing out on a large percentage of the music (any competent speaker I don't really think has such a major problem, and often times--as in with Kans, per se, the lack of bass is the expense of such a wonderful quality of delivery that you don't *really* care that much).
I'm looking at it from a "house sound" perspective as well as what I could gather it would match up with, style of delivery, etc. And the impression I got was simply a bit limp, very detailed and pleasant and smooth but not terribly dynamic, grippy, or exciting.
They may very well have been 'Tonally accurate' but also that's another thing I don't really give TOO much credence to particularly today where all speakers are heads-and-tails, night-and-day better than most things available 30 years ago due to material sciences and other advancing technologies (and again, in the example of say, Linn Kans, which were really not terribly accurate--honking all over the place--they were still magically fun to listen to). BUT ON THAT FRONT, I'm actually not sure how tonally accurate they were given that they sounded kind of....flattened, as it were, again in a Castle kind of way. (If that makes sense).
I got the feeling that they'd mate okay with Naim amps, though that might be a bit of a waste of a naim amp and the combination might be a bit hard, and that they also would work very well with Valves.....but this would be using the smooth, robust sound of Valves to add some warmth into these things that are fairly colourless.
Look it's all personal. We all know that. But if it were between a pair of those 5+'s and a completely innaccurate, coloured, flawed and frequency impaired set of 15" monitor golds.....look out sister, it's no question for me.