Not sure about your question. The 3 inch soft dome is a characteristic of all ATC models above the 19 or 20. In the 19 or 20 the soft dome is simply part of a larger woofer. It still has a 3 inch voice coil behind the dome but they don’t need a double spider in the 19 or 20 because the rubber surround serves to assist in alignment. So what you hear on the 19 or 20 in the mid range is similar to the larger models with a dedicated separate 3 inch dome. The difference on the three ways is better clarity, more beautifully clean low distortion SPL (dynamics) and greater bass extension as you get into the larger of the three ways.
All of the above is independent of Active or a Passive. Active is always slightly better than passive - better phase coherency and clean active crossover as well as much reduced IMD distortion (active power amplifiers are separate from each other and therefore IMD from one driver amp circuit to another simply cannot happen)
So pick your poison according to your budget. Personally, I would go passive in their two ways (more cost effective) and always active in their three ways (best performance). The driver integration was already superb when ATC outsourced the tweeter - now that they build their own in house tweeter with no ferrofluid, I would say the driver integration especially in their Actives is unsurpassed. (The new tweeter is basically a miniature 3” double spider dome - so it’s behaviour matches the mid range perfectly at all SPL levels - unlike most speakers which have a sweet spot in SPL range where they sound best)
I agree you should stick to ATC. I first found ATC in ‘94 and have lived with them since then. The first three years with ATC was like a re-education in listening - you learn so much from them and after a while you cannot live without them. There are many other fantastic soundung speakers around but ATC are one of the most revealing, totally natural sounding and utterly faithful to the recording. I have not found anything that can do all types of music from piano to vocals to organ to strings or percussion with equal ease. Other speakers I have tried all tend to have strengths in some areas and weaknesses elsewhere. Nothing stands out with ATC - everything balanced - so if this suits your requirement it is a great choice. For many, understandably, ATC just doesn’t have enough pizzazz or fun exciting coloration that audiophiles seek. As long as you recognize your taste matches that of professional users then you will be happy for life with a large ATC no matter the investment.
