Since I just got my 990/7125/LFM-1Plus combo installed yesterday, I've been messing around with all of the settings.
When looking at the Bass Matrix page, it says that when the Front Speakers are set to Large, and the Sub is set to LFE, the sub will get LFE+Sm Spearer Bass.

When the sub is set to LFE+L/R, it gets LFE+Sm Speaker Bass+L/R.

Why is that? I don't get why more bass "Sm Speaker Bass" is being added to the LFE (.1).

I played L.O.R.-1 earlier in DTS and swapped between the sub being set to LFE and LFE+L/R.
When in LFE+L/R, the bass was too overpowerfull.

There is no way I can see to get just the LFE (.1) to the sub.

"Small speaker bass" represents the bass from any channel set to "small". Therefore, if you had "large" L/R's, a "small" center, "small" surrounds and sub set to "LFE", your L/R's would run full range, and the center/surround channel bass would be redirected to the subwoofer along with the LFE.

If you wanted just the LFE in the sub, all channels would need to be set to "large".

Best,

Scott

You are exactly correct here - LFE+L/R causes the mains' low frequency information (everything below the specified crossover point) to be reproduced twice (once to the mains, which are set to large, and once to the subwoofer). It's an option that is included because some people prefer it, but it does lead to very pronounced low frequency (especially on bass-heavy movie tracks). It sounds like you'd be best off setting all speakers to small (at which point the sub will simply be "on") and dialing in crossover points.