Yes, HAMP has long been an advocate for the RX2 if a good sub (or two!) is present. I didn't realize that he had come to the conclusion that the RX8 was a better speaker than the RX6 or that he was close to getting the RX8.
I too have been wondering what to do on this front. For a long time now I have subscribed to the notion that radiating area of a speaker is important. Radiating area must increase dramatically as frequency drops in order to maintain similar distortion characteristics. I learned this from Bill Dudleston of Legacy Audio. All speakers of course have larger woofers than tweeters for this very reason. Legacy Audio takes it very seriously, which is evident as you move up their model line to the bigger (and very expensive!) speakers.
My next system will have very capable subwoofers. So I have seriously considered going to bookshelf speakers to save money. And HAMP's experience with the RX2 was further motivation to do so. However, I always come back to this idea of having lots of radiating area. The RX2 has a single 8" woofer, which will have a radiating area of approximately 201 square inches. That woofer operates from the bottom of its range all the way to the 2 kHz crossover point.
Now, the RX8 has three 6" woofers. Two of them operate from the bottom of the range to the 300 Hz crossover point, and then the third woofer takes over and runs up to the next crossover at 2.2 kHz. So in the bass region the RX8 has a radiating area of 226 square inches, and in the midrange has an additional 113 square inches to work with.
One could argue that the bottom end will be taken care of by the subwoofers, but only up to maybe 80 Hz or so. How about that area between 80 and 300 Hz? The RX8 (all else being equal of course
) will be more capable than the RX2 even when both have the advantage of a subwoofer filling in the bottom two octaves.
The way I see it, the RX8 has 12% more radiating area between 80 and 300 Hz, and the midrange unit does not have to be bothered with playing those frequencies. The RX2 woofer has less radiating area and must simultaneously play 80-300 Hz and 300-2k Hz. The RX8 "should" sound better and subjectively feel more at ease because it is not working as hard for a given volume level as the RX2 would be.
That's all theory, of course, and it is ignoring some supposed advantages that bookshelf speakers have due to their small size (imaging being one of those). HAMP, did you get the chance to compare the RX2 and the RX8? If so, I'm quite interested in what you thought about them in comparison to each other?
Edit: Oops, looks like the drives in the RX8 are 6", not 6.5" That gives them a radiating area of 113 square inches each, not 132 square inches. So the advantage is not quite as large, but is still there. I've fixed the numbers above.Edited by bkeeler10 - 1/28/13 at 1:22pm