35Hz - 25kHz -- A Partial 'Purist'?

I am firmly in the full-range camp and use a REL Stadium III. I think a lot of people simply do not take the time to fully optimize the sub, which involves at least five major simultaneous variables: (1) room placement, (2) crossover point, (3) crossover slope, (4) sub output level, and (5) phasing. This is an extraordinary challenge that is beyond the desire of many (and the capability of some) to solve. I'm not trying to insult anyone, it's just that I think most people aren't willing to put out the effort to get it right. (Heck, even mine isn't fully optimized, due to home decorating issues...) But when you finally DO get it right, there is simply no comparison at all. And then you find that listening to a non-full-range system is just no longer satisfying. So like many things in high-end audio, it's both a blessing and a curse.:)

One other comment, which is not generally considered in these discussions: The combination of a high-quality monitor and an excellent sub, when set up properly, will almost always outperform a single large speaker system in a given room. (Caveat: any crossover point over 50Hz is too high to ever integrate seamlessly, so forget about tiny monitors that roll off at 80Hz.) This is due to the extraordinary flexibility of the sub/sat system in taming room modes in the bass while allowing for optimizing placement for midrange smoothness and imaging qualities. Yes, you can occasionally buy a full-range speaker and find a room placement which optimizes both imaging and the bass range (not to mention spousal aesthetic issues), but it is quite difficult, maybe even rare, and much more of a lottery than many people will admit. While the sub/sat system is not perfect either, it at least gives a much higher chance of actually achieving an overall optimum in the real world.

P.S. I would agree, I've never in my life heard an 18" cone that could keep pace musically. There's a reason RELs use 10" cones, even on their biggest subs.

There seems to be some misunderstanding about low bass in small rooms, so in an effort to clear this up....

Any enclosed (airtight) space gives a 6dB/octave BOOST as you go down in frequency, beginning roughly where the wavelength of the sound wave is equal to the longest room dimension. For a typical room length of 20 ft, this means that the room is actually adding 6 dB/octave starting around the 50-60 Hz range. This means that a sealed loudspeaker, which would normally roll off at 12 dB/octave in free space, will actually roll off at only 6 dB/octave in the room. Deep bass is actually much easier to achieve in small rooms; the trick is to prevent the speaker or sub from overpowering the midbass region, typically around 60 Hz. This again is a real advantage of the monitor/sub combination, since the main speakers start to roll off in this range and the REL can be brought in lower, around 40 Hz in this example, thus giving a flat in-room response. In contrast, a full-range loudspeaker will often exhibit a midbass peak in this same 50-60 Hz region, which is often very difficult to eliminate, even with careful placement.

This is also why it is so important to "match" loudspeaker size to room size so you don't end up with a hump or suckout. Let's say you put a large full-range speaker that is flat to 30 Hz in a room that begins boosting at 60 Hz; you will end up with a 6dB RISE from 60 to 30 Hz and it will sound "thuddy". Same with a monitor that rolls off at 60 Hz in a room that doesn't boost until 30 Hz; anything below 60 Hz will be MIA and the sound will be incredibly "thin". This is especially true of vented monitors which will roll off at 24 dB/octave through this region. Again, the sub/sat combo allows you to tune virtually any combination of sub and sat to the particular room it is placed in, by virtue of the ability to tune the response through this critical region.