Well, this has been a long journey and I’ve learned an awful lot - many thanks to the contributors on this forum for their generosity and knowledge.
I had started this quest certain that I’d end up with Bowers & Wilkins speakers. On the way I had an extended romance with some Italian beauties: the gorgeous Sonus Faber Serafino G2 - but ended up with something very different indeed.
I had started with the 803d4, but found the midrange too recessed. Later I had an extended audition with the 802d4 which is better - but greatly preferred its big brother, the 801d4: somehow the midrange was better formed, more refined and of course, one has more of everything.
I very-nearly ended up with the 801d4 - I was offered an excellent price for an ex-demo pair - but their sheer size and slightly ungainly (is that unkind?) appearance scared me off. I greatly admired these - but unlike with the Sonus Fabers, I didn’t love them.
I had another audition with the Serafino G2 and was poised to order their big sister, the Amati G5, when my excellent dealer in Oxford suggested trying the Magico A3…
Chalk and cheese - so very different. The A3 didn’t have the full body of the Serafino (I’m going to have to tone down my analogies here, otherwise I’ll get in trouble…), but did have much greater clarity in the mid range and treble and a punchier (although less extended) bass. We then switched to the A5 (same price as the 801d4 BTW). I was deeply impressed by the sheer fluidity of the sound: utterly seamless and life like. The bass was also more extended than the A3 and, being a closed-box design, was natural without bloat.
These A5 speakers aren’t anything great to look at; probably one of the most-boring designs out there: a box of speakers… but the sound, that’s something different. The frequency response is ruler flat within my hearing range; the dynamics are superb and the coloration minimal. I did my own tests and whilst the Serafinos added a host of harmonics (as did the B&W, though to a lesser extent) the A5s were almost completely pure. Those graphene/carbon fibre & aluminium honeycomb drivers are working extremely well indeed - and this new design is being used in the considerably-more-expensive 2023 “S3” and 2024 “S5” models.
So I pulled the trigger… also replacing the NAC-A5 speaker cable with Chord EpicX (shielded), which seems to give a less muddled sound (for want of a better description).
The speakers apparently need about 500 hours on them for the bass to really come up (I verified this with a demo pair) so I’m still in the early stages - also waiting for the “A-Pods” isolation feet to arrive from California. I’ll fine-tune the speaker positioning once these arrive - the masking tape on the floor shows where my dealer initially set up the speakers.
Magico make far more expensive speakers, but these A5s really are excellent; they seem to combine the clarity of an electrostatic, but without its limitations. No, they don’t have quite the visceral punch of that set of 801d4s I almost bought - but Alon Wolf (Magico founder) is adamant that much of this is “a combination of noise, distortion, and phase inaccuracy”. Certainly different sounding - more precise, delicate even; definitely takes some adjustment, but I’m enjoying the sound.
Thank you again to everyone who contributed to my earlier queries - this has been a rewarding and enriching experience.