Mid sized room -Full range vs Monitor

I would consider that room big enough to work with all but the biggest floor standers. I think the more important question is: do you prefer the sound of monitors or the sound of floorstanders. Where do you come in budget wise? That may play a more important role in the situation.

I believe it is smart to question the characteristics of the room like you have, though.

Integrating subs is difficult, but if you get it right you're not going to believe how wide, deep and tall the soudstage will be!

Three things come to mind:

1) use a proper *stereo* electronic crossover. There are NO compromises allowed here. Driving monitors full range is a bad idea and defeats one of the main advantages of a sat/sub setup: liberating the mini monitor's woofer from deep bass.

2) make sure the woofer and subwoofer materials have similar sounds. Snap the cones w/ your fingers and find out if the sound is alike.

3) set the subs somewhere along an arc intersecting the monitors and extending no more than 30 degrees to the outsides of the monitors. The subs could sound better inside the monitors or outside, depending on room acoustics.

If you cannot ( or are unwilling to ) do the above stick to 'full range' speakers. It took me years before I could do this move, but now that I did it there's no turning back.

I bought a Marchand X9 Deluxe electronic crossover w/ Cardas RCA's and had Dan Wright modify the power supply and send the boards to cryo treatment. This was done to follow a Channel Islands passive pre-amp and get the clarity of a passive pre and the dynamics and constant output impedance an active pre-amp can deliver. The electronic crossover drives four monoblock amps: 30W class A Marantz Ma-5 Esotec for the mini monitors and 125W Kenwood L-07M high current amps for the subs. Speakers are Dan Wright modded Swans M-1 mini monitors and NHT SW2-Si subs.

Like I said, it took me years to get here--but there's no turning back.

With psychic power and primal intensity,

Given your room size, you can still accomodate a full-range floorstander. The only question is how large can they go. I had no problems previously with Sonus Faber Grand Pianos in my smallish 11'W x 17'L room. However, in one review by John Atkinson in Stereophile, it was suggested that stand-mounted mini-monitor loudspeakers may offer the best chance of sounding good in the widest range of moderate-sized listening rooms compared to their larger counterparts. Two-way minimonitors hold the advantage of being preferred in the broadcast industry as a nearfield monitor as they emphasized definition and intelligibility over extensive dynamics and subterranean bass response which made them better suited to studio applications.

Having that said, I still feel your room would be able to accomodate moderate-sized floorstanders easily. I reckon many would recommend floorstanders over standmounts as the advantages of the former outweigh the latter in the long-run, given your room size. Getting to know which won't sound boomy would be tricky and may need a bit of research unless you can try it out in your room yourself.

The fact that your rear wall ( behind the listening position ) is not concrete is a fantastic bonus....concrete is very reflective and will not leak out energy and consequently you may get overly long reverb times. The best place to have a "leaky" or less reflective surface for bass frequencies is the wall behind your head. Since it is concrete you may want to use more acoustic panels/carpets and wall hangings to absorb than usual... but you may be pleasantly surprised at how good it may sound (even with full range).