(I'm posting this in both threads, because.)
I 'reverting' the Sony Japan 5.1 release back to 4.0, by using MMH to silence the C and LFE channels.
It's a little hard for me to judge the result, because I am no fan of the 1970s quad mixing philosophy used for Blow by Blow and Wired -- lead guitar in the rear on most tracks, rhythm section up front. I really dislike it. And it's not because I use tiny surrounds -- I use the same Behringer Truth passive monitors all around. Plus two 12" subwoofers. System is 'crossed over' at 80Hz. The room is modestly treated for broadband reflections, and Audyssey does room EQ. I sit in the sweet spot in the near field. I know the album itself really well, having been a fan of it since the mid 70s (not to mention I'm currently practicing the bass part of 'Led Boots' to play in a music project honoring JB, so I know the stereo sound of that one really well now).
I compared my reverted 4.0 to the 5.1 (but with Center turned OFF in my AVR, so it was essentially 4.0 + LFE....call it 4.1. The AVR in this case should be distributing C content into LF and RF*). I could easily and rapidly switch between the two since they are files played in foobar2k. My main test tracks were 'Led Boots' and 'Blue Wind'.
The Result:
Misgivings about the mix itself aside, the 4.0 reversion sounds 'OK' on its own...but anemic compared to the 4.1. There is bass, for sure, but it's perceptibly very obviously reduced compared to the 4.1. The whole experience becomes more visceral and immersive in 4.1, because the front (where the bass instruments are) becomes in better perceived balance with the rears. It doesn't help the reverted 4.0 that the mix is so dry (the original stereo mix had a fair amount of reverb on it) -- in 4.0 it sounds rather clinical and disjointed.** Adding back the LFE seems to ameliorate that issue.
This is NOT the case for every 5.1 mix that I have 'reverted' to 4.0 -- Nektar's Remember the Future (which has low level C and LFE content), for example, does NOT suffer such a massive perceived bass reduction when C and LFE are silenced.
That said, the Wired SACD bass in 4.1 is not ideal. It feels just a bit too much, on the verge of being overwhelming, at times - which I believe one critic here said about it already. My setup can handle it, nothing sounds boomy or distorted, but I can easily imagine it being obnoxious in some setups and some playback levels. An ideal mix might have the LFE at a bit lower level. Or no LFE at all, just more bass in the main channels...my preferred solution....
My experience with Wired hints that the derived LFE content on the SACD mix consists of lowpassed content of the main channels BUT that those main channels are themselves highpassed -- i.e., they actually lack that bass, as opposed to the practice of 'doubling' bass in mains and LFE. (Such highpassing is actually best practice, to my mind. ) I don't know for sure that this is actually what's happened. I'd have to do spectral analysis on a per channel basis to test it.
Regardless, it still seems to my ears that the bass is a bit 'pumped up' when LFE is included. One question is, is that perception accurate to the original quad mix, or is it from juice added for a .1 mix? An obvious way to approach this is to compare the 5.1 mix and reverted 4.0 to actual 70s-era quad media sound. I don't have any matrixed/Q8/CD4 rips of Wired, but I'd love to to see how much, if any, the bass has been pumped up on the SACD.