Harbeth SHL5 vs SHL5 PLUS

Good question. I find all Harbeth speakers (actually most classic BBC designs) play well at lower volumes, especially the larger ones. The slight exception is the M30.1 which sounds a bit bass light at low volumes, although still quite good.

I used to run B&W 700 and 800 series and still own 600 series. The higher B&Ws definitely prefer a higher volume to sound their best. Or a very high current amp if you want to play well at low volumes.I used McIntosh.

Other modern speakers with super stiff cabinets and driver materials also tend to prefer a bit of volume (Wilson, Focal etc) so sound good.

One thing to keep in mind though the SHL is a big speaker so it will not sound as fast as the M30.1 not offer the pinpoint imaging of the P3. But I think it offers a nice full presentation where instruments sound natural and reasonably full bodied in real space.

BTW, not sure if I mentioned, mine took a while ot break in, like over 200 hours. Before that they sound fine but a bit sluggish and slightly uneven.Nothing nasty, just not as musical as after they break in.

I have had both plus and original SHL5.All things being equal the difference I hear are as follows:
1) top end a bit more extended and clearer. Enough so that older model is more forgiving.
2) midrange a bit less fuzzy and a bit more snap.
3) bass is where the Plus benefits MOST.Tighter which address a bit of bloat that would a times be present on original SHL5.
4) drivers are more coherent as a result of improvement's.
I will not comment on imaging or staging because those aspects are too subjective.
Next stop 40.2. BIG FAN

@HIfipf... Thanks for your input. How about scale as in size of image I.e. Instrument and voice size? Pretty close?

Image size is tough for me to comment on because of my set up.The plus is a bit better focused as a result of its improved extension and overall improved clarity.The height is improved, as a result the cymbals hang higher and pin point a tad better. Voice is same size but more focused. Scale is tough but I would say about the same
The in your face improvement is the bass.Tighter and better integrated, so coherence is improved.
Both models are great but Plus is just a more coherent and clearer sound.

@Hifipf...Thanks!