I currently own 3.3R's and traded up from 1.6QR's so I can give you some recent comparisons. First of all,the 3.6R is a different animal than either the 1.6 or 3.3.In comparison with the 3.6R the 3.3R is less dynamic overall(not drastically assuming the same system for both) with tighter bass and more coherence of the panel drivers. The changes were made to the X-overs,drivers and revision of the cabinet frame. . Tonally they are very similar and soundstaging wise also very close.The 3.5R was mostly a X-over change and typically Bi-amping a 3.3R will bring the sound closer to the 3.5R
As for the 1.6QR. This is a very good speaker that is more amp friendly,a fairly constant 4 ohm load,where the 3.3R will dip in the midrange to about 3 ohm or so. But as for the sound, they both share the maggie magic and correctly driven and placed in the listening room will disappear. The 1.6 is the more vivid and forward presentation with tighter bass and sounds very,very good IMHO.
However...The music really starts to get serious with the 3.3R. There's just no getting around that awesome ribbon tweeter. sweet,extended without any trace of hash or hardness and imaging and soundstaging that compare with the best. This is a world class speaker all the way! Feed it fairly high power tubes or high power solid state(you can read all the hundreds of "which amp should I use for my maggies"" articals and threads here and elsewhere. but current and stability of the amp into lower ohm loads are key. A very good tube pre-amp, and the best front end sources you can afford and the correct placement in your room will make you smile for a very long time! The presentation is more relaxed with a better sense of instrumental placement and staging. Vocals are breathtaking and have more natural space. Deeper and wider soundstaging.and deeper,more authoritative bass. If you like classical,chamber,vocal,any jazz , this is your speaker. The cost difference is very minimal as was pointed out. Probably $300-$400. max to get into the 3.3R's. I'd check them out for sure!
As for the 1.6QR. This is a very good speaker that is more amp friendly,a fairly constant 4 ohm load,where the 3.3R will dip in the midrange to about 3 ohm or so. But as for the sound, they both share the maggie magic and correctly driven and placed in the listening room will disappear. The 1.6 is the more vivid and forward presentation with tighter bass and sounds very,very good IMHO.
However...The music really starts to get serious with the 3.3R. There's just no getting around that awesome ribbon tweeter. sweet,extended without any trace of hash or hardness and imaging and soundstaging that compare with the best. This is a world class speaker all the way! Feed it fairly high power tubes or high power solid state(you can read all the hundreds of "which amp should I use for my maggies"" articals and threads here and elsewhere. but current and stability of the amp into lower ohm loads are key. A very good tube pre-amp, and the best front end sources you can afford and the correct placement in your room will make you smile for a very long time! The presentation is more relaxed with a better sense of instrumental placement and staging. Vocals are breathtaking and have more natural space. Deeper and wider soundstaging.and deeper,more authoritative bass. If you like classical,chamber,vocal,any jazz , this is your speaker. The cost difference is very minimal as was pointed out. Probably $300-$400. max to get into the 3.3R's. I'd check them out for sure!