The AtC website gives exactly the same dimensions for 19A and 40A. The 40 passive is a bit less deep, due to not having the amp modules on the back, so is the smallest of the three. The 19 passive, unlike the active, is a standmount (though effectively occupies the same space). The obvious primary difference between 19A and 40A is that the 19 is a 2-way system, with combined bass/mid driver, whereas the 40A is 3-way, with that sublime 3 inch dome unit plus a dedicated bass driver, albeit a fairly small one, and of course separate power amps for mid and bass. I don’t know what differences there may be inside the cabinets.
But actually I was wrong, the 2-way SCM 20ASLT is a bit narrower, though also slightly smaller, so that is their smallest floorstader, so the 40 passive is their second smallest, then at joint 3rd 19A & 40A (then plenty more larger).
Of course it depends hugely on layout in the room and other room characteristics, not just size - and one person’s overblown bass is another’s idea of just starting to come on song!
Alternatively, how the recording team wanted it may be how it is supposed to sound, sounding wrong if filtered out… There are a lot records where the bass has been curtailed in the recording process. (With vinyl that sometimes needed to be done because of the limitations of the medium, notably when longer recordings were squeezed in.) The important thing is for the bass to be well controlled, and I imagine ATC will have ensured their amps do that, though obviously limited by resonances in the room.
Having had monitor type speakers for 40 years now, I personally wouldn’t want anything lesser. The question of course is what suits the buyer and only that person can decide.
Yes, my expectation is that the 40 would dig deeper (and that it would do even better on the mids). Whether that is too much depends on the room itself, not just floor area (shape, height, construction, furnishings, speaker and listening positions) - and of course on the listener’s taste.
ATC SCM 100 speakers driven actively from a NAIM 552 and comparable quality source, in the right room would OR could sound brilliant at least.
I have a friend who partly rebuilt his house to give him a room 30" x 20" for music. He has spent £10K on room panels to give him the bass “he” wants and still is not totally happy.
My room/living room is about 19 x13 ft with helpful non parallel walls. I am on my 3rd pair of B & W 802s ( D3) having had the previous two generations. They are driven by a 500DR and at last I feel confident in whatever I play the room is not being driven. However if, like me, you like big orchestral music at a realistic level, Mahler who else, and get hold of some Reference Recordings CDs they might be too much for the room.
Do recording engineers make discs to sound “good” on speakers that are not totally full range?
At the last Windsor Show I managed a few words with Mike Valentine, he of “Chasing the Dragon”. Room interface was his first topic to be addressed in quality hi-fi.
You’re right IB! I doubt there’d be room for anything other than the hifi. I meant, of course, my lounge measures 5m x 5m, or 25m². I still stick by my assertion that this is medium side of small rather than large.