Should I bother to try a subwoofer?

Yes, do bother. Just don't get crazy with the volume. You don't want to know it's there when on, but miss it when it is off. And don't be afraid to move it around the room a bit for optimal sound.

Tostado,

If you happen to be an unethical lout:

You can order the SMS. Skip the EQ section and x-over section. Just use the RTA. Move the sub until you get the best results on the video readout and you will be very close to optimal placement. Trying to do the same thing by ear is -IME- both much more time consuming and much less reliable. You can then return the SMS.

I am not suggesting that a highly principled fellow like you would ever do such an unethical thing - merely observing (purely theoretically) that you could.

OTOH, if you tried that, you might end up exploring the x-over and EQ functions (IME, hard to live without once you've tried 'em)and decide to keep the thing, which might morally justify the whole evil plan.

Good Luck,

Marty

Yeah, Marty, I did think about that. Trying to be better in my old age!
And, I trust my ears-- as a musician and teacher I've relied on them. I've done multitrack mixing, live mixing and things which make me focus on various aspects of sound and listening that most folks (outside a forum like this) probably never think about.
I have (so far) wound up with a frighteningly low volume setting on the Q150E (so low that some would say "why bother") and I'm kicking it in around the frequency where the Dynaudios supposedly kick out. The biggest problem right now is dragging myself out of that room so I can get other things done. I am really pleased with the sound. Wife is away for a couple of weeks, so now is the time to really take it in.

I also run my REL Q150E relatively (but appropriately) pretty low...and as an older (but still amazingly handsome) musician/soundman I also have "experience specific" tastes in this stuff (unlike the "teeming masses/great unwashed" non musicians who have irrelevant tastes...heh heh). I do adjust the level sometimes but only in tiny increments. I suggest 3 things: An angled Neutrik plug (hard to find but cool) and an angled IEC cable (Audioquest sells an IEC angled adaptor) in case you want to put the control panel side back against a wall (I do this), and a "chicken head" knob for the level pot in case it IS backed against a wall...you can adjust the level and more readily tell where the knob is set.

Tostado,

IME, the problem with set-up by ear is that you're trying to optimize for 3 major variables at once (and a few minor ones, too). Smoothest response will vary with room position, as will the native output level from the sub (as reinforcing or destructive room interactions have their way with the low hz output). The placement with the smoothest response will likely require a different level setting on your sub than the placement with the second smoothest response. Finally, the x-over frequency (and slope, if applicable to your set-up) must be optimized for the particular placement you've chosen. As above, likely to differ (unpredictably) between best, next best, etc. And you've got to pick the best compromise....

I'm sure you're better equipped for the task than I am, but it's an awful lot to ask of anyone to optimize that equation by ear.

Good Luck (and kudos on the self-improvement project, too).

Marty