George,

Good lateral thinking - something I've considered/used for quite a while, as it didn't strike me as 'right' reducing all the speakers levels to a greater or lesser extent.

I calibrate my DSPs in the 2nd way you described i.e. using the highest level DSP(s) as the 'datum' (in my 5.0 config. with L/R as the 0 datum, the Centre is @ -0.5dB and the 2 rears are @ -2.5 dB, so not too far off anyway). Personally, I'm not overly hung up on having the system's ABSOLUTE level matching the THX standard - for me getting the RELATIVE levels right is the most important.

On the same subject, I wonder how many of us actually listen to THX standard movies at +0 (87) all the time/at all anyway? FWIW, I use this level as a starting point, not a 'must have/can't change'. Judging by some past threads on music listening levels, one mans/womans 'loud' is another's 'quiet', as it always will be.

Just my 2-p's worth

Andy

System 1: Control 15, 818v3, 800v3, 861v6, DSP8000SE, DSP7200HCSE, DSP8000.2, SW5500, HD621, 650BD, SkyHD, Radience XE, TH65PF12
System 2: MS200, 5200
System 3: MS200, F80
Sooloos: MD600: 2x3TB
On the move: Explorer 2, B&W P7W
Bedroom: F80+i80