adding M-Audio SBX10 active subwoofer to 2-channel monitoring

I'm trying to do the same thing w/Rokit speakers.  I have the 5 inch powered monitors and am in search of a good deal on their sub...the interconnect scheme makes that the easiest solution.

From a techno view...be aware that the freq response quoted for each speaker is based on some degree (db) of relative output level.  So if the NS are rated to 60 Hz low end and the SBX is rated to 200 Hz high end, each at -3db, then the point at which they leave ref (0db) might be something like 80 and 180 (for example, unknown).  I read a review where a self-proclaimed 'engineer' claimed the NS roll off pretty badly from ~90 Hz.

The intuitive answer is to set the SBX so the mixes you found 'too boomy outside', sound like that inside!  I suspect the truth is you'll have to live w/the combo long enough to establish your ref by experience.

Enjoy!

I am using that same sub with ADAM P11s. It's not the greatest subwoofer on the planet, but considering its price it's quite a bargain.

Check the actual frequency response of the Yamahas. I've heard they're good down to only 60Hz or so, but you should verify that. Set the crossover frequency on the sub to just slightly above the point where the NS10s drop 3db. Don't try to set the sub range any higher than necessary, as its flatness isn't as good as your mains. Verify by measurement that you haven't set the crossover frequency too low and left a gap in the range.

Where you place the sub in the room is critical. All your low frequency problems are going to be exaggerated after adding the sub. Keep in mind that it doesn't necessarily have to be placed right in between your main speakers, as those very low frequencies are quite omnidirectional.

A more important concern is placing the sub where it is least affected by room resonances. There is a trick you can do: set the sub on your chair, play some nice bass-heavy commercial material and audition the sub from various locations in the room close to the floor. Find the spot where it sounds best, then move the sub there.

If you don't have any bass traps in the room yet, now is the time to start thinking about them. All your room's acoustical flaws are about to be highlighted.

One last tip: avoid the temptation to crank the sub. It might sound awwsome, but it also might end up making your mixes sound very thin. For playing video games, however, feel free to crank that sucker up!