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A Possibility... Or a Labeling Screwup?

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Bob Squires Jr

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I have a copy of Nimbus Records "Ravel - Piano Works Vol 2 (Vlado Perlemuter).
The label says it's UHJ (Ambisonic) but the back cover says that it can be played back using the QS system.
Will QS decode UHJ? Is there any such thing as a dual encoded LP??
Or did record A get stuffed in record B's cover?
(It's a great album of Piano work regardless!!)

-Bob
 

kerr_avon

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Jun 26, 2007
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Aldershot, UK
QS was Very close to UHJ. All the stereo compatible systems were more or less left-right front-back compatible, including dolby stereo. It depends how picky and academic you feel like being. Personally, I thing that any surround is better than nothing at all. Yay UHJ btw:}
 

Bob Squires Jr

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From the back of a Nimbus records LP (Shura Cherkassky - Mussorsky - Pictures At An Exhibition) reads:
"Full dynamic range recording. This stereo record has been encoded from surround sound master tapes and
conforms to the BBC/NRDC UHJ specifications. Stereo playback will give enhanced depth.
Surround playback through 4 loudspeakers using a UHJ decoder will reproduce
the ambience of the original performance with improved fidelity.
The Hafler loudspeaker arrangement or Regular Matrix,
QS or SQ decoders may also be used although precise results cannot be guaranteed due
to the variations in the specifications of these decoding methods."

Is there a difference between RM & QS?? :confused:
Hafler loudspeaker arrangement?? :confused:

Has anyone been able to accurately decode these with Audition?
(not sure if I asked that before.... my mind is going!) :kitty:

I have about 30 UHJ records (Nimbus, Unicorn-Kanchana, Music from York, etc)
and It would be cool to hear them in all their glory. :phones
 

Lucanu

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Cabras, Sardinia, Italy, Europe, World, Solar syst
RM and QS are the same, the only difference I know is that the first was used to bypass copyright issues.
AFAIK no-one knows exactly how to decode UHJ recordings with Audition right now, but there are tools which decode UHJ to b-format to 5.1 in Nuendo. That would be a start.
I never tryed it because I don't have any UHJ recordings.
 

Michael Orme

New member
Joined
Feb 10, 2006
Messages
4
Location
Rhyl UK
I have a copy of Nimbus Records "Ravel - Piano Works Vol 2 (Vlado Perlemuter).
The label says it's UHJ (Ambisonic) but the back cover says that it can be played back using the QS system.
Will QS decode UHJ? Is there any such thing as a dual encoded LP??
Or did record A get stuffed in record B's cover?
(It's a great album of Piano work regardless!!)

-Bob
Some stuff here about
it.http://fgouget.free.fr/ambisonic/Ambisonic_AM91.shtml
 

MidiMagic

Senior Member
Joined
Jul 5, 2010
Messages
298
RM was a Japanese government standard name for all matrices of that type, including QS.

Ambisonic BHJ is close to both QS and H. QS will do an acceptable job. The back image is a little off.

For a better job on BHJ, put an SQ decoder right back speaker at center back.

You can substitute Dolby Surround for QS.

You can see the phase relations (as stylus vectors) here: Quadraphonic Systems
 

Doug G.

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Rochester, Minnesota
Very interesting information but I have a feeling Lou Dorren would have some issues with the page author regarding some of the assertions made re CD-4.

Doug
 

MidiMagic

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Joined
Jul 5, 2010
Messages
298
CD-4 is not viable.

I have never heard a CD-4 recording that worked all the way through it. Yes, I heard 4 channels. But I also heard enough noises to totally ruin the experience.

Several factors affect my judgments here:

1. At the time quad was big, I was a college student. I didn't have the money for new records or equipment. All of my gear and recordings were used or home-built, except the Audio Technica pickup. All of the CD-4 recordings I ever had sounded awful in CD-4, probably because they had already been played on standard stereos. Every tiny scratch on the record surface made a loud CRASH! They were almost inaudible in stereo mode. And there was an overall background hiss on all of these records in CD-4 that was not there in stereo mode. Even the calibration record that came with the CD-4 demodulator someone gave me made these sounds.

The crashing sounds sounded about the same as home recorded CDs where the audio input overdrove the A/D converters. The hiss sounded like an electric fan blowing air had been turned on when the pickup was placed in the groove. And using the cue control also made loud bangs.

2, Every time I heard a demonstration in a music store, the same hiss happened. But I soon realized why. The salesmen were using the same records on ALL of their turntables, whenever a customer wanted a comparison between systems. Not all of the turntables had CD-4 pickups, so the records were damaged when the standard pickups were used.

3. One time, I actually heard a CD-4 record demonstration that wasn't making any noises - until a woman standing nearby looking at something else looked at her reflection in a window and applied some face power. The turntable was about 3 feet away. Suddenly, I heard the all too familiar crashing sounds. The store owner repeatedly cleaned the record with products made for CD-4 records, but he never got rid of all of the crashes.

That was the day I finally decided that CD-4 was not a viable system. CD-4 is just too fragile to work in a mass market.
 

Mark Anderson

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aRMANIA
Any 4 channel matrix decoder will decode UHJ but of course will not be as what was intended for listening by the engineer. UHJ used shelf filters that other matrix formats did not use.
For more info you can check out the Ambisonic FAQ at http://members.tripod.com/martin_leese/Ambisonic/faq_latest.html
And the Sursound Surround Sound Discussion Group which is an email group at http://www.ambisonic.net/sursound.html

Matrix H is closer to QS, BHJ is UHJ. UHJ is the term used on consumer delivery formats.
 

Mark Anderson

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From my calculations, BHJ is closer to QS than H is.
You are of course entitled to your opinion. But BHJ is the engineering specification for encoding the W, X and Y direction signals into two channels. The two channels, called Left and Right, can then be transmitted using conventional stereo media before being decoded back into W, X and Y. The BHJ format has been designed to be mono and stereo compatible. In practice, BHJ is the only UHJ encoding that has been used for commercial record releases. For this reason UHJ has become a synonym for BHJ and UHJ is the symbol you will see on BHJ encoded LPs and CDs.
How can the ability to encode height information and mono compatible be close to QS?

Below is info from the Ambisonic FAQ written by Martin Leese
6. What were Matrix H and HJ?
Matrix H and HJ were surround sound encodings used by the British Broadcasting Corporation in the late 1970s for experimental FM radio broadcasts. Matrix H was based on the QS quadraphonic system and was modified to HJ which was based on Ambisonic principles.
7. What is UHJ?
Two-channel UHJ was extended into a hierarchy of C-Formats for 2, 2.5, 3 and 4 transmission channels, termed BHJ, SHJ, THJ and PHJ, respectively. The extra channels are used to augment the two base channels to give improved horizontal surround sound and, for four-channel UHJ (PHJ), periphonic (full-sphere) surround sound. In practice, only two-channel UHJ (BHJ) encoded material has ever been released. For this reason UHJ has become a synonym for BHJ, and UHJ is the symbol you will see on LPs and CDs.

In the mid to late '70's during the height of the Quadraphonic era, Nimbus released LP's in the Sansui QS matrix format (see the Classical Quadraphonic Discography).
Those record numbers are NIM-2101 (QS),NIM-2102 (QS),NIM-2106 (QS),NIM-2107,NIM-2110 (QS),NIM-2109 (QS) & NIM-2111 (QS)
 

MidiMagic

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Joined
Jul 5, 2010
Messages
298
Matrix H is NOT QS.
The front center modulation (for an LP) is a clockwise ellipse with the long axis lateral
The back center modulation (for an LP) is an anticlockwise ellipse with the long axis vertical

Matrix A was QS with the basic decoder
Matrix B was SQ with the 10-40 decoder
Matrix C was QS with Variomatrix
Matrix D was SQ with Front-Back logic
Matrix E was a tetrahedral equal separation matrix suggested by Peter Scheiber
Matrix F was BMX
Matrix G was a modification of BMX with a phase difference between stereo channels less than 90 degrees to eliminate the stereo error
Matrix H was a refinement of matrix G with a 45 degree phase difference, with modulations halfway between QS and BMX
Matrix HJ is a refinement of H with a 22 degree front phase difference and a 67 degree back phase difference. Its front modulations are closer to QS than those of H.

"For this reason UHJ has become a synonym for BHJ, and UHJ is the symbol you will see on LPs and CDs."

And for the same reason, UMX is found on may items that are actually BMX. Also, almost every magazine article I have that mentions this system calls it UMX, not BMX, even though it refers to only the basic matrix.

Note that filters are used with UMX because the carriers encode the full separation info up to only 3 KHz. Above 3 KHz, the system is pure matrix.
 

MidiMagic

Senior Member
Joined
Jul 5, 2010
Messages
298
How BHJ is mono and stereo compatible, but still close to QS.

The front channels of BHJ are very close to the QS modulations, but they have slightly elliptical modulations. The center front has a slightly clockwise motion, but the left and right front are slightly anticlockwise.

The back channels are more elliptical, so center back does not disappear in mono playback. They have anticlockwise rotations that are close to the BHX modulations, but have more vertical modulation than lateral modulation. The long axes of the ellipses are vertical, but lean to the left and right modulation, with the center back long axis being vertical.

Height is encoded by using rotation in the clockwise direction, instead of the anticlockwise direction. An overhead sound is a clockwise ellipse with the long axis vertical.

I determined these stylus motions by applying the Ambisonic encoding and decoding equations using Microsoft Excel.
 

Disclord

900 Club - QQ All-Star
Joined
May 19, 2005
Messages
944
Location
Plattsburg, MO (just outside Kansas City)
And UHJ is unlistenable in stereo - with a 40 degree phase shift for CF sources, UGH! Decoded it sounded even worse. Awful, awful, awful. But defended like crazy by those who thought it was the ultimate. I'm SO glad it never gained any foothold.
 

martin.leese

Member
Joined
Aug 25, 2009
Messages
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Location
Calgary, Alberta, Canada
And UHJ is unlistenable in stereo - with a 40 degree phase shift for CF sources, UGH! Decoded it sounded even worse. Awful, awful, awful. But defended like crazy by those who thought it was the ultimate. I'm SO glad it never gained any foothold.
You hear what you hear, and nobody can argue with that. However, the number you quote for the centre-front phase difference is incorrect. For UHJ this is 32 degrees. You may be thinking of the BBC's Matrix H (42 degrees). It is interesting that the BBC later modified Matrix H because of an adverse reaction from some listeners. Their new system, the BBC/NRDC System HJ, had a phase shift of about 30 degrees.

UHJ was designed using research (conducted by the BBC) on the perception of phase differences. UHJ was a compromise intended to provide acceptable results for the majority of listeners. The problem with this approach is that there is no such thing as an average listener.

People who want to hear UHJ for themselves might like to download "super_chicken1" from my Google Site for temporary downloads. This piece has always sounded superb to me in stereo, and even better in surround sound. Obviously a UHJ decoder will work best for this, but a Pro Logic II decoder should also work well.

Regards,
Martin
 

Disclord

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Joined
May 19, 2005
Messages
944
Location
Plattsburg, MO (just outside Kansas City)
You hear what you hear, and nobody can argue with that. However, the number you quote for the centre-front phase difference is incorrect. For UHJ this is 32 degrees. You may be thinking of the BBC's Matrix H (42 degrees). It is interesting that the BBC later modified Matrix H because of an adverse reaction from some listeners. Their new system, the BBC/NRDC System HJ, had a phase shift of about 30 degrees.

UHJ was designed using research (conducted by the BBC) on the perception of phase differences. UHJ was a compromise intended to provide acceptable results for the majority of listeners. The problem with this approach is that there is no such thing as an average listener.

People who want to hear UHJ for themselves might like to download "super_chicken1" from my Google Site for temporary downloads. This piece has always sounded superb to me in stereo, and even better in surround sound. Obviously a UHJ decoder will work best for this, but a Pro Logic II decoder should also work well.

Regards,
Martin
Yes, I screwed up the phase shift for CF - total brain fart on my part. My problem with UHJ (BHJ) is I just think they went too far with the compatibility for center back and such in mono - phase shifts are just 'unpleasant' for me when I hear them like CF in UHJ. Now full G-Format Ambisonic, like the first demo DTS CD I have from Jeffrey Silberman sounds incredible - I can hear people talking all around and can even 'place' them in distance. 2-channel UHJ - especially decoded - just sounds like a phase-y mess to me. But G-Format from B-Format - WOW!

I wish there were some SQ Ghent Mic recordings available since it could do correct 360 imaging too, and had a 4-3-4 B-Format mode so that no "logic" decoding was needed.
 
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