Wilson Sasha

If you like your Avalons but want more bass add a pair of subs. Why
change your speakers. A pair of RELs would do nicely or even JL Audio
though I prefer the RELs coz the connection is easier and no X crossover
etc. If you want deep percussive bass, I suspect neither the Sasha nor the
Aviors will be enough. FWIW I run my Aviors with a pair of REL G1 subs
and the quality of bass ,in a room almost the same size as yours , is
outstanding.
All the best
Pradeep

I would encourage for larger power amp.

Your room may be better suited to the Sophia 3, but given your need I can see why you're looking at the Sasha. Personally,I would have the room analyzed and acoustically treated before I considered new speakers. Your equipment is very nice, the lack of bass slam might just be standing waves. Speaker placement, the listening position and acoustic treatment to remove the rooms anomalies may solve your problem.

What's your definition of lowest bass and/or deep powerful bass? Are you talking about sub 30Hz at >95dB, high volume levels? The Avalons you have go down into the 30-40Hz region although they won't go super loud in that area.

I second what Egrady said above. If you are severely constricted about how you can position the speakers and listening area, you may never be able to obtain really deep, smooth bass. I will note that your Pass amp isn't noted for bass slam. Also, what you're missing could be effected by your turntable/arm/cartridge setup.

Could you describe what's missing on a specific recording? Compare what it sounds like to what you think it should sound like.

Not possible, it will give a lot of acoustic problems. In the time I did consulting I met a few people with Wilson Watt puppy's. I still don't understand why people love these speakers. they had all the same problems. Wenn they play dynamic music the house starts to make all kinds of noise. Why choose people for speakers which give this acoustic problems. Wenn I ask this question to them, they do not know what to say. Maybe it it too confronting. Beside this it can give a deep stage, but I heard enough speakers which are superior in this part. Wenn I play my classical music on it, a violin sounds far from real. It never convinced me. A few years ago I had the change to hear the Alexandria 2 with the most expensive Ayre and Transperent cables. The best thing Wadia has these days. I listend for about 1,5 hours wiht my own music. I always start to check if a sustem can give the right dimensions of instruments and voices. I started with Nils Lofgren Acoustic life. Nils and his guitar were much too big in proportion. So I asked them why it is too big. Then they said: we had some problems witht the filter. I thought okay and I am Santa Claus! 2nd test, Jacintha is her name. Nummer 5. the crossflute need to be played a few metres behind the speakers on the left side. But they were on the same line as the voice. Wenn people do shows like this I alwsays make my comments based on facts. They are mostly never capable of saying anything on my remarks. They positive thing I want to say is that the X100.5 is a great match for Wilson Audio. I sold my XA100.5 to a person who owns the puppy 7. I found it superior then with Ayre.