Thanks for the advice guys. It’s all appreciated. I’ll try and address the points raised below.
My space is large at 10x10x4 meters. It’s been acoustically treated as it’s used as a video recording studio, so the sound is nice and flat with very little reverb. Hard surfaces are covered with rugs and furniture, sofas, chairs etc so it’s not bright by any standards, quite the opposite.
I tried the Meta Ref 1’s with this system a little while ago. I really liked them, they came across to me as a slightly warmer version of my then current B&W 804D3’s. The difference wasn’t so much as to make me swap them out though.
I appreciate speakers need running in, although it’s not something I’ve come across before, hence the original question about reasonable expectations. I’d be surprised if it’s going to make enough of a difference to tame the 606’s as much as think I would like, but I’m more than happy to try. I suspect it may be a combination of that and my ears adjusting to the new sound as mentioned here by others previously.
I’m wary of adding more boxes. Even to borrow an XPS would mean shelling out another £4k if it worked.
I realise this may sound like I’m jumping through hoops to make a pair of speakers bend to my will but I really like the look of the Kudos, the walnut fits my decor perfectly, and aesthetics are important to me. And more importantly I am sure I can hear a depth and resonance I’ve not heard in any speakers I’ve owned before, so I really want them to work.
On a side note, I did audition a Hegel 390, then 590 a while ago. They were matched with an Aurelic Vega 2.1 and Focal Kanta 2’s. That was a great sound. If I was in the market for a full system at the time, and had the funds, I would have taken them there and then. That’s why the Hegel was in the back of my mind as a Naim replacement when I first heard these Kudos.
Anyhow, the Hegel arrived today. I’ve only had an hour to do an A/B comparison so I can’t really give an informed opinion. First impressions though are it is indeed less up front. It’s a bit easier to listen to for me, maybe my 60 year old ears are getting sensitive! There does seem to be a drop off in detail though compared to the Naim. Probably to be expected. And perhaps that’s what makes them seem softer. Maybe adding an Aries Vega will put that detail back in, albeit with the danger of there being too much information again.
As I said, I’ll reserve judgement as to wether that works better for me for now, it’s early days and I’ve a lot more tests to do, but thanks again for taking the time to comment. Every little helps as they say.