DIGITAL At Least a Dozen 2002/2003 Elliot Scheiner 5.1 Mixes Have a LFE Issue (info/list/fixes inside)

[Cheezmo]

BTW its worth remembering that 10ms is only a single cycle of a 100Hz signal.

Not sure what the point is. That means that a 5ms delay would cause a 100Hz signal to be cancelled out it if was equal energy on the LFE and the other channels. The issue isn't that there is a slight timing delay but that in various configurations it will cause low frequencies to be cancelled out, either in bass processing or the "in the air". Small yes, but possibly VERY significant.

 

[JonUrban]

Just eyeballing it, it looks ok to me, but I'm not totally sure. I had this problem with Layla and A Night at the Opera, these "classic rock" types of albums don't have a lot of heavy low-bass transients in the LFE that would present as a 'big squiggle' in a waveform readout that makes it easy to determine.

If you can send me this track as a FLAC via WeTransfer or something I can check it with my phase correlation meter and we can be sure - feel free to PM me a WeTransfer link or something.

I just posted "Pretty Woman" to my Mega and sent you a link. See what you think. Again, it's a live track, so maybe it does not apply.

 

[steelydave]

I just posted "Pretty Woman" to my Mega and sent you a link. See what you think. Again, it's a live track, so maybe it does not apply.

Looks good to me - another one to tick off the list!

 

[MrSmithers]

Cool Dave I see you got the delays for the R.E.M.s

I was doing it by eye so it's good to see it's on the same track. This is what I had very tentatively put down but I feel it defo needs to be verified!!!

Out Of Time - 7ms
Monster - 7ms
Green -7ms
Reveal - 4ms
Up - 7ms
Automatic For The People - 7ms
Around The Sun - 3ms
New Adventures In Hi-fi - 2ms

 

[steelydave]

Cool Dave I see you got the delays for the R.E.M.s

I was doing it by eye so it's good to see it's on the same track. This is what I had very tentatively put down but I feel it defo needs to be verified!!!

Out Of Time - 7ms
Monster - 7ms
Green -7ms
Reveal - 4ms
Up - 7ms
Automatic For The People - 7ms
Around The Sun - 3ms
New Adventures In Hi-fi - 2ms

Thanks, yeah, I've been adding them as I see them. I think what I might do is bold (or something) the delay times that have been verified.

 

[Fourplay]

That'd be really good. Like a separate tab or something? To have an issue/fix HQ would be cool. I have some of the titles listed as -

Neil Young - Harvest - Channel assignment errors on certain tracks
Porcupine Tree - In Absentia - Inverted LFE and centre timing issue
Coldplay - A Head Full Of Dreams - Added LFE info in fronts
Jeff Beck Group - Incorrect speed on first 2 tracks
Jeff Beck - Blow By Blow - Incorrect phasing (corrected on Analogue Productions SACD)
The Beach Boys - Pet Sounds - Wrong Channel assignment track 1
Ten Years After - A Space In Time - Swapped fronts/Rears
Keane - Hopes And Fears - Swapped fronts/Rears
George Benson - Breezin’ - LFE issue
Guns N' Roses - Appetite For Distuction - My Michelle channel delay issue

Some of these are discussed here:

https://www.quadraphonicquad.com/fo...eassignment-recommendations.19693/post-225843
I will edit this post if they move the thread to the new section.

 

[steelydave]

Spent a couple of hours with my old friends Donald and Walter, and having checked all the tracks I can confirm the following:

Donald Fagen The Nightfly - 4ms exactly
Donald Fagen Kamakiriad - 4ms (it's actually more like 4.2-4.3ms, so you can get it a little closer if you eye match with Audacity or similar, but 4 is fine with MMH)
Steely Dan Everything Must Go - 7ms (more like 6.8-6.9ms, but same thing, 7 is close enough)

 

[perzon57]

Spent a couple of hours with my old friends Donald and Walter, and having checked all the tracks I can confirm the following:

Donald Fagen The Nightfly - 4ms exactly
Donald Fagen Kamakiriad - 4ms (it's actually more like 4.2-4.3ms, so you can get it a little closer if you eye match with Audacity or similar, but 4 is fine with MMH)
Steely Dan Everything Must Go - 7ms (more like 6.8-6.9ms, but same thing, 7 is close enough)

And you can actually hear the difference when you've fixed that 4ms?You must have a pretty good setup and better ears than me.I have no problem with that,but I know my ageing ears would not hear the difference anyway. So it's a fun read and I'm very relaxed about this as I have no means to fix it,and that's fine with me.

 

[AYanguas]

Ok so I just downloaded the media music helper update (great program by the way thank you!) and want to fix Sea Change. Do I just add 8ms of delay of the LFE to each track or 8ms to all channels except the LFE?

Yes.

It reminds me the answers that used to give Kosh, the Vorlon Ambassador on Babylon 5.

 

[AYanguas]

And you can actually hear the difference when you've fixed that 4ms?You must have a pretty good setup and better ears than me.I have no problem with that,but I know my ageing ears would not hear the difference anyway. So it's a fun read and I'm very relaxed about this as I have no means to fix it,and that's fine with me.

It can be really much relaxing to see the wave forms aligned in an Audacity display.

Also relaxing to really know "technically" that the corrected track will really sound "better" or "different", even if our old ears cannot notice the difference. We know that it will not be a placebo esoteric fake effect. We know it is a "real" change, and for some of us is very worthwhile this Hobby task. Go figure... We are improving some of the good mixes/masters done by good sound engineers.

 

[Soundfield]

And you can actually hear the difference when you've fixed that 4ms?You must have a pretty good setup and better ears than me.I have no problem with that,but I know my ageing ears would not hear the difference anyway. So it's a fun read and I'm very relaxed about this as I have no means to fix it,and that's fine with me.

I doubt anyone could hear any difference even at 8ms. 1ms = approx 1ft at the speed of sound. Can any one tell if their LFE speaker has been moved by 4ft with respect to the other speakers? I'd suggest not.

 

[perzon57]

It can be really much relaxing to see the wave forms aligned in an Audacity display.

Also relaxing to really know "technically" that the corrected track will really sound "better" or "different", even if our old ears cannot notice the difference. We know that it will not be a placebo esoteric fake effect. We know it is a "real" change, and for some of us is very worthwhile this Hobby task. Go figure... We are improving some of the good mixes/masters done by good sound engineers.

I'm very relaxed about this as it is and will not give it much more thought. I prefer to use my spare time to listen to multichannel music not to measure and maybe fix.I play my music in my music room from disc and will continue to do so. Good luck to all in the hunting for ms.

 

[AYanguas]

I'm very relaxed about this as it is and will not give it much more thought. I prefer to use my spare time to listen to multichannel music not to measure and maybe fix.I play my music in my music room from disc and will continue to do so. Good luck to all in the hunting for ms.

No objection. That is good for you. And also for many of us.
Each one spends their time, if they can, on what gives them the most pleasure.

 

[AYanguas]

I doubt anyone could hear any difference even at 8ms. 1ms = approx 1ft at the speed of sound. Can any one tell if their LFE speaker has been moved by 4ft with respect to the other speakers? I'd suggest not.

Sure Not, because Audyssey or whatever corrector will have run after the move.

 

[Cheezmo]

I get 4ms for Let It Snow

 

[Cheezmo]

I don't believe most of the the tracks on R.E.M. Around the Sun have a 3ms delay. A few do, including the title track though. I lost track as I went through them thinking the first one or two that didn't were the exception, but the delay is actually the exception.

 

[steelydave]

I doubt anyone could hear any difference even at 8ms. 1ms = approx 1ft at the speed of sound. Can any one tell if their LFE speaker has been moved by 4ft with respect to the other speakers? I'd suggest not.

Like I said, if you have a full range setup with no bass management going on, maybe not. But if you're like me, and your speakers are all set to 'small,' so that the low frequency content from those speakers is being sent to the subwoofer, there's absolutely an audible effect on the quality and extension of bass frequencies as a result of (as @jimfisheye astutely pointed out) a comb filtering effect caused by the delay.

If you don't believe me, take any 5.1 file you have make a stereo downmix, then make another stereo downmix where you delay the LFE by 4-8ms, and A/B the two files on headphones. The difference it immediately audible.

 

[jimfisheye]

The offset should be handled in samples IMO. Kind of the base unit in question.
True that any 0.000-whatever is likely within the margin of imperceptible...
But the offset can be dialed in right to the exact sample and since we're touching it anyway, might as well be accurate! And completely avoid any maddening shootout between 0.00 something within our perception bias. (Be a little lazy and round off. Now try to see if you can tell the difference. Repeat... Um, no! Dial it right to the sample!)

 

[Soundfield]

Like I said, if you have a full range setup with no bass management going on, maybe not. But if you're like me, and your speakers are all set to 'small,' so that the low frequency content from those speakers is being sent to the subwoofer, there's absolutely an audible effect on the quality and extension of bass frequencies as a result of (as @jimfisheye astutely pointed out) a comb filtering effect caused by the delay.

If you don't believe me, take any 5.1 file you have make a stereo downmix, then make another stereo downmix where you delay the LFE by 4-8ms, and A/B the two files on headphones. The difference it immediately audible.

I’m a strictly 2 ch or 4 ch, analogue, man and have no means of conducting such a test, however interesting it might be. I’m not disputing that there is such a thing as comb filtering, I’m just a little surprised that it creates such a big audible effect from such small delays. But I’m happy to accept the results of your ears. Indeed, I am even more happy now – I’ve never liked the sound of LFE channels anyway and have even more reason not to want one now!

 

[Cheezmo]

Good Lord this has me going through my whole library and there are going to be lots more. Billion Dollar Babies DVD-Audio (4ms). Jeff Beck Rough & Ready SACD (3ms)....