Thanks for the info guys. It sounds like DTS-HD would be the format to use for the theatrical dts 5.1 mix and the 2.0 laserdisc mix.
If I understand right, I can apply a 48db lowpass at 80hz cutoff on the lfe.wav and then apply a 12db highpass at 120hz cutoff on the sr.wav and sl.wav to make it sound right on a home theater system? Should I enable downmix to 2.0 when encoding? I'm really an audio newbie in almost all regards. I guess I understand the lingo but I don't know what parameters to use lol. BTW, my first test encode for the theatrical DTS came in at 2.2gb.
EDIT: OK I applied the 48db lowpass on the LFE and it definitely cuts out everything but the bass. Using Audacity, is it possible to adjust the LFE level to +17db like you recommend? I thought I would try the amplify effect but that caused a lot of clipping.