I've had these Rush DVD-A's for ages but finally got around to ripping and properly listening to them recently. I'm not even sure what to say really, but what a missed opportunity...they really sound like they're mixed by someone who doesn't understand how to use surround to it's maximum potential at all.
So while I'm speaking about this album specifically, the same goes for all the Rush 5.1 mixes as they were all mixed in exactly the same style.
The most frustrating thing about the mix (aside from how front heavy they are) is Rich Chycki's tendency to put instruments in to far too many speakers, so you can't pinpoint anything - everything ends up sounding like a mono wall of sound (or noise, delete as appropriate). Case in point, on the song 'Fly By Night' he has a single acoustic guitar coming from all three front speakers, and then reverbs of the same guitar from the rear speakers. The same goes with vocals, and drums, so you end up with everything coming out of every speaker in a big mush. It's just made worse by the copious use of reverb in the rear speakers. I listened to the 5.1 mix on headphones, with the 3 front speakers mixed to one ear, and the two rears in the other ear so I could get a sense of surround placement, and you literally have the whole band thundering away in the front speakers, and only cavernous reverb in the rears. The only discrete element in the mix is during the chorus, when Geddy sings 'Fly by night, away from here...' the two guitar 'pling plings' fly toward the back of the room. What's the point? Why are all the instruments fighting for space in the front? He doesn't even use the center speaker discretely either, most of the time it sounds like a mono sum of the front left and front right speakers and as such, it ruins the phantom imaging of the front speakers. The occasional discrete elements in the rear speakers are sto o few and far between that they're actually distracting - they almost end up like 'hey look at me!' party tricks that cruelly remind you of how much better the mix could have been. I think if they were going to go with a conservative surround mix they should have done it in the 'big stereo' style that Tom Petty uses and not have these occasional discrete flourishes in the rear speakers.
I also find the bass to be muddy and indistinct most of the time. The weird thing is if you listen to the LFE channel on a full range speaker, it's almost exclusively dry bass guitar (and a bit of kick drum and sometimes synths). The LFE channel hasn't been low pass filtered, so you can hear everything. The dry bass guitar sounds amazing, full of growl and bite, which makes the lifeless way it sounds in the full mix all the more baffling.
To add insult to injury the mixes have been slammed pretty hard with compression - the DR rating for the album is between 10 and 11, which is better than the stereo mix fares, but still poor for a 5.1 mix and way lower than this style of music deserves. The DR database says the old CD mastering of the stereo mix was DR14.