Regarding Sonos Amp: I have several Sonos Amp’s and they have no problem at all powering whatever I’ve connected them to, including the Bowers and Wilkins 702 S2 (which according to the impedance and phase plots is not exactly the easiest to drive). Do not mistake this with the “Sonos Connect Amp” which is a completely different product than the “Sonos Amp” and capable of a fraction of its power.
Independent measurements show the Sonos Amp can push close to
200 Watts without distortion, which I think will be more than enough regardless of whatever speaker you get. If that’s not enough for you, it rules out the majority of most amps anyway and so you’ll have to look into more exotic speakers and amps in that case. Here’s a link to the review if you’re interested:
https://www.audiosciencereview.com/...ds/review-and-measurements-of-sonos-amp.6957/
Regarding speakers: I’m an ex-B&W fan, having realized how much better the other options are out there at the same or lower price.
I own Bowers and Wilkins 702 S2 tower speakers, and the Ascend Sierra Towers (with RAAL option) I recently bought are much better, for a fraction of the price. I wish I had someone to tell me this before I bought the $4500 MSRP B&W 702 S2’s, which is why I am replying to you here — to suggest that you consider other options, and skip my mistakes.
Therefore I would recommend against the B&W 706, for example, and suggest you consider something like the Ascend Sierra 2-EX instead (for a bit less price, it’s almost certainly going to sound vastly better), or other speakers that have good measurements like Revel or many others (Bowers and Wilkins does not, for example).
I can add my review of the 2EX when it arrives (it’s on the way) if you’d like, but I already can speak from experience (at length) regarding the Bowers and Wilkins 702 S2 towers and Bowers and Wilkins CM6 SM2 bookshelf speakers, both of which I’ve owned. After owning Ascend speakers + Rythmik subwoofers (and realizing how much better they are for a fraction of the price), I can no longer recommend B&W to anyone anymore (as I formerly had), for any reason, really.
I don’t mean to single out Ascend either, except for the fact this they’re the only example I have that I’ve personally compared to B&W extensively over many hours of listening. Others, like Revel, JBL, etc. are reportedly amazing too — I just haven’t heard them in person. I’ve heard mixed things about Klipsch and SVS (and personally I have owned SVS subwoofers, and find them to sound vastly inferior to Rythmik subwoofers, so I avoid the SVS brand — but maybe that’s just me).