Switched to LFE cables with subwoofer ON (Triton 2's left at LARGE)... WOW! I got much more bass punch in 5.1 mode, and, surprisingly, also in 2 channel music mode! I ilistened to the Overture from Phantom of the Opera (cd) first with subwoofer on, and then with it off again (with all power again going to the large fronts). I could FEEL the bass far more strongly with the LFE/subwoofer tied in, probably sound in the 25 HZ and less range. Can it be that the t757 rolls off some bass under 25 HZ or so if no subwoofer is operating, and not just LFE rolloff? I didn't change any other settings... didn't use ENHANCED BASS or raise the subwoofer speaker level, it's still at 0 db gain.

Also, with the subwoofer connection (no t757 power amplifier tied to this...it's audio pre out), the subwoofers inputs in the Triton's are now getting all power from the Triton amps..isn't that like connecting an external amp to the AVR, and thus taking some power load off the AVR?

Also, I swapped out the Sat 50 center for a Supercenter XL. Another WOW!

I listened to Triton 1's the other day...awsome speakers. I moved my Triton 2's closer to the rich bass I heard on the 1's, though still not all the way there. I don't know, I'll listen to my newly energized Triton 2 Cinema system for awhile before thinking about upgrading to 1's, but I've never heard such immersive, smooth, powerful, enveloping sound as the 1's produce.

Thanks for the feedback, we have been learning that this LFE attenuation is fairly common in receivers and, for movie soundtrack and multi-channel music playback, we are now recommending the use of the LFE input and a setting of "Large" L/R Main and "Yes" for subwoofer. This should ONLY make a difference on playback of source material with the ".1" channel present.

In answer to your question, there is no real difference in the "load" to the driving amplifier.

I've replayed that same "Overture" track from the "Phantom of the Opera" CD maybe 6 more times, doing the same alternating between sub OFF and sub ON at the exact same volume setting, so that I'm putting all bass headed for the Tritons through the front/large speakers channel only and then through both those channels plus subwoofer) and there is a visceral difference in the music. I can FEEL it more with the sub ON setting, like it vibrates my breastbone (the Triton 1's I listened to sure did).
One of the questions I have been asking my dealer is why my prior Bose 901's, with only 150 watts of amp power available, emitted a more visceral bass to music than the Tritons with 1200 watts of power each. Well that isn't true since I connected LFE cables and turned subwoofer on. (Isn't the T757 diverting some bass as well as LFE signals to the sub pre-out output and just maybe the Triton sub amp is doing a better job than the T757 amp was doing processing that through the front large channels?)
I understand what you're saying about how only .1 channels should be affected...maybe this is unique to my particular NAD T757, or T757's and the way they programmed. I'd be interested to get any feedback from anyone else who tries the LFE/subwoofer hookup and can tell a difference in 2 channel bass produced also.

If you here it, its happening. So that means the NAD is doing something to the bass in your setup when switching sub to Yes. The effect should only be to send LFE info down the sub-out cables, but it may well be the NAD is attenuating bass to the speaker outputs whenever No sub is selected. This would not be standard bass management, and begs the question of whether a crossover is in place on the L/R mains, or some double bass setting is engaged. Does the NAD have a stereo bypass mode? That should certainly eliminate any bass management questions.

My advice - ask NAD what's happening. Two channel stereo should be unaffected with Large (full-band, no crossover) L/R mains when subwoofer is selected, or not. If they've decided their receiver(s) can't drive full range speakers and have attenuated bass output, I guess that would be good to know.

Thanks for the feedback. I tried the "stereo" listening mode (I usually listen in what NAD calls "EARS", which includes the center speaker and surrounds at lowered volume, or "ENHANCED STEREO" which raises the volume to surrounds and also plays the rears.
I couldn't detect a difference in "stereo" between sub OFF or ON, so the bass reduction effect is gone in stereo mode, as you predicted.

Interestingly, if I disconnect the LFE cables when listening mode is EARS, and then put sub ON, there is a distinct drop off in bass levels, so the receiver is definitetly diverting bass to the sub channel in that mode (which makes sense to me...aren't subs supposed to play bass below wherever the crossover is, not just LFE feeds? The receiver has no way of knowing that the sub and large/front outputs are in fact going to the same speakers in this case) I haven't tried disconnecting the LFE cables with sub on in "stereo" listening mode.

Thanks for your help!

Rick

Maybe the safest setting for lots of AVR's (especially those with less power) is to have LFE hookups, subwoofer ON, just to make sure the various receivers' possible bass rolloffs involving multiple speakers are bypassed with a sub setting that lets them direct the bass to the subs? I woud suggest that the best generic setting for any set-up for most receivers is large/fronts plus LFE connection and subs ON.

I can now play with full bass in any listening mode!

Rick