Where are you located?
I do not see the A45 bs available in the US!
How much are they going for?
My best insight on these (Vento 820.2) speakers (and the tweeter in particular) is they have
amazingly smooth drivers!
Looking for things which you may not like (from a critical perspective):
1) They do incorporate a fairly aggressive wave-guide. I do not generally find it offensive; however, if I A-B it directly against a Philharmonic Audio BMR, the openness of the BMR (which, by design has the best off-axis FR I know of) is more often preferred! Just so you understand what I am talking about, here is the graph of the BMR's frequency response. Red is On-Axis, Blue is 30 degrees Off-Axis, and
Green is a whopping 80 degrees Off-Axis and it is still tracking right around +/- 3dB across the bandwith!
Like I say, this openness is generally preferred; however, there were still certain sounds where the Cantons nailed the sound over the BMR's to my ear - this was trumpets and trombone. My simple mind thinks maybe it is because the wave guide better represents the dispersion of the bell of a trumpet or trombone, which are largely directional. Woodwinds such as sax sound better on the BMR's. Even though a sax has a bell, the sound is dominantly coming out of the first open hole along the sax body and does not have the directional aspect of a horn/bell like the trumpet where all sound goes out of the bell. I play sax in a couple of Jazz bands, so I know the acoustic sound of these horns well enough to have confidence in my assessment. I don't know if I am correct in attributing it to the wave guide/dispersion, but it seems reasonable. Instruments such as strings (violins, etc) and piano that tend to radiate in all directions thrive from the dispersion of the BMR. That said, we are not talking huge differences. There were many places where it took quite a bit of critical listening to reach these generalized conclusions. Interestingly, I liked the character of symphonic chimes better on the Canton, but a cymbal crash was preferred from the BMR.
2) The Canton has what I would consider a well executed "bass hump". It is common for a bookshelf speaker to over emphasize mid-bass to compensate for not having lower-bass. While it is an infringement on the accuracy of the speaker, I, personally accept this as the lesser of evils (since it is done well - it smoothly increases and rolls off on the bottom without abrupt "steps") - without a sub, I'd rather have the extra "faux" bass. I have heard other speakers with a bass hump that was horrid due to poor execution!
This would be a bad speaker to add a sub to if you will not use bass-management to high-pass the speakers and get rid of the hump which is not desirable once the sub is in play.
However, with a standard AVR type control of bass (high passing the Cantons),the bass hump is eliminated, allowing the AVR a flat FR to work with.
To be clear, the Cantons are among my favorite speakers (especially for the $600 I paid for them, although I consider them a very good but at their current price of $720). I am critiquing them using the BMR's because that is the least expensive speaker ($1350) that I know of which is
decisively better than the Canton
to my ear. Honestly, I suspect the MB Quart to fall short unless you are especially sensitive to the wave guide. As I said in another thread, the tweeter of the Vento is pretty special (to my ear)!
Of course, the A45 BS does use Canton's better (best?) drivers than the Vento, so you should expect improvements over the Vento!
