DIGITAL Channel Error Samples: Phase Inversion and LFE Delay

[HomerJAU]

Having fixed a few albums this morning I thought I'd upload 4 additional 30 sec examples for members to compare original released mixes with fixed mixes:

Beck: Guero - Earthquake Weather (Phase Inverted LFE)
Donald Fagen: The Nightfly - IGY (LFE delayed by 4ms)
Porcupine Tree: In Absentia - Chloroform (Phase Inverted C, LFE delay + LFE boost)
R.E.M.: Automatic for the People - Man On The Moon (LFE delayed by 7ms)

Use the same link as in first post here

NOTE: Fair Use claimed - These 30 sec samples are for test and education purposes only

 

[HomerJAU]

I just re-upped Porcupine Tree: In Absentia - Chloroform (I forgot to fix the 9ms LFE delay in the initial version).

 

[César]

Thanks for posting this. This is one of my go-to demo tracks for tight, deep bass (and a discrete surround mix)!

I can hear differences between all 3 files:
File 1. Sound(ed) fine up until now!
File 2. Tighter and deeper bass. This is my favourite of the 3.
File 3. This appears to have the least amount of bass of the 3. Like someone cranked down the sub.

Next question: Can the File 2 fix be done in Audacity and if so, do I apply it to the entire album, and... how?

Hi,
I have front speakers set as large (and large they are). I've got a subwoofer too.
I can tell the difference between 1 and 2 (two sounding much fuller in terms of bass), but 2 and 3 sound the same to me.
Funnily, I own the DVD-A and bass sounds much more "intense" and "round" than in the samples you uploaded.

 

[ssully]

To help those wondering about issues in the recent 'Elliot Scheiner LFE Issues' thread and whether they can hear a difference with fixes applied, here are 3 short 30 sec samples to compare:

General request to QQ folk...if you refer to another thread, please provide a link for those of us who want to catch up.

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

 

[ssully]

(BTW: Beck: Sea Change SACD has same issues as the BDA - The DVDA has no issues)

copying this here that I just posted on the first thread:

I can confirm from my own investigation of the Sea Change DVDA that the front vs read/LFE phase is correct on all the tracks....except maybe the last track (track 12). There's something odd going on with the rear channels on that one.

However, the LFE is still slightly misaligned on all of the DVDA tracks. By 9 ms.

Track4



Track 12


(misaligned, not inverted, because the LFE transient consistently starts 9 ms after the same transient in the other channels)

 

[ssully]

Hi,
I have front speakers set as large (and large they are). I've got a subwoofer too.
I can tell the difference between 1 and 2 (two sounding much fuller in terms of bass), but 2 and 3 sound the same to me.
Funnily, I own the DVD-A and bass sounds much more "intense" and "round" than in the samples you uploaded.

FWIW, in your setup any phase cancellation would be purely acoustic (in-room). In bass managed setups, cancellation would occur electronically before output from the sub.

 

[HomerJAU]

Hi,
I have front speakers set as large (and large they are). I've got a subwoofer too.
I can tell the difference between 1 and 2 (two sounding much fuller in terms of bass), but 2 and 3 sound the same to me.
Funnily, I own the DVD-A and bass sounds much more "intense" and "round" than in the samples you uploaded.

I checked this out. The DVDA has louder LFE channels, in fact all channels are louder.

But checkout the relative differences between BDA and DVDA:

Fronts and Centre on the two first tracks: more than -3db lower on BDA
Rears are more than -3db lower on BDA

01. The Golden Age

02. Paper Tiger

I haven't compared the two (listening) but these would sound quite different balance wise.

 

[PK]

OK, so I downloaded the 11 tracks to a USB stick and stuck it in the Oppo. Currently my setup is 4.1 with speakers set to small on the AVR. I tried to not look at the full track title on the tv in an attempt to do a blind listening test.

First Run, Sub-woofer OFF:

• Not much difference between any of the tracks except for track #2 which seemed fuller.

Second Run, Sub-Woofer ON:

• I thought the difference was most notable on the fixed version of "Chloroform."
• Not much difference on the "Guerro" tracks.
• The original unfixed tracks sounded fuller on the R.E.M. and IGY songs.

So my results seem like a bit of a mixed bag...I'll try again at a louder volume. That, and maybe edit the titles for a blind test...or just turn the tv off...
Anyway, thanks to everyone trying to sort this out.

 

[ssully]

No one has sorted out which SACD releases have the L/R inversion and which do not?

 

[JediJoker]

Phase cannot be "inverted," only shifted forward and backward in time. It is polarity that can be inverted. Both issues can be present in the same signal at the same time.