When I first received the 990, the auto-calibration didn't work, giving me large setting for my surround and small for my front pairs along with very wacky subwoofer setting. Last night I gave another try on auto-calibration (wife rearranged the furnitures) and it did wonderfully this time. When I checked manually the setting was almost identical. So give it another try if you weren't successful before, yours might work just like mine.

What exactly is the difference between "large" and "small"? (hey....this is a family show!)

Let's say I have a pair of front speakers that can handle anything and at power levels exceeding my amp's power rating. Let's also say that I've got a kickin' sub like the LFM-1 and would like to take advantage of that....

So, do you set the mains as "small" and choose a low crossover at 40hz? Or do you set them as "large" and set the sub at "L+R/LFE"? Does "large" imply no bass management at all?

I haven't done any exhaustive testing on my system yet, but so far I'm diggin the "large" setting.

Cheers,

In theory, "large" refers to a speaker capable of reproducing signals down to the neighborhood of 20Hz. As such speakers (not counting units with powered subs tucked inside) are extremely rare, there are cases where folks elect to use "large" if their speakers have a -3dB point of anywhere from 30Hz to 40Hz (the assumption being that there's not much in that range in most music and that the .1 track in movies is generally home to the major low frequency muscle).

Personally, my Studio/60's have a -3dB point of 30Hz and a -2dB point of 42Hz. I used them with no sub at all for over a year and a half, then added an SVS 25-31PCi and settled on a 40Hz crossover point as the best balance for music. Since I replaced the PCi with an LFM-1 I've been running them crossed over at 60Hz, and I've been quite pleased with the results.

If you have truly full range loudspeakers like Gonk said, then you can set them as "large" and only the LFE will be directing to subwoofer. Even though manufactures claiming such, such deep bass from their tower speakers, most of us can benefit from redirecting bass to the subwoofer. I have three front speakers with built-in powered woofers (Sound Dynamics RTS-P100 L/R and Def Tech CLR 2500 as center)but adding active subwoofer produced much more satisfying sounds. My back surrounds speakers (Sound Dynamics RTS-7)are not able to produce anywhere near bass like the front speakers. But when I tried auto calibration for the first time after I received 990, it gave me screwy results. However this time it gave me more accurate results. So even if the auto calibration gave you strange results, try it again, it might work better for you this time just like mine. I followed exactly same procedure both times but this time around gave me more accurate results.