UHJ four channel?

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SmcAustin

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Hi! It's a rainy day so I dug a little deeper into my collection and found a cd of Stockhausen Kontakte (Music & Arts CD-648) with four channel UHJ encoding. I don't have a decoder so I'm resorting to DTS-Music for playback which is pleasant but not the four corners experience possible.

Do any readily available apps have the ability to decode this and convert to FLAC or WAV? I searched here but there's a lot of content about Ambisonics formats and I didn't notice a specific discussion of my question.

I don't know when I'll want to hear Kontakte again, but I do have a few Nimbus cds that are probably also encoded. Thanks!
 

stevendive

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Hi! It's a rainy day so I dug a little deeper into my collection and found a cd of Stockhausen Kontakte (Music & Arts CD-648) with four channel UHJ encoding. I don't have a decoder so I'm resorting to DTS-Music for playback which is pleasant but not the four corners experience possible.

Do any readily available apps have the ability to decode this and convert to FLAC or WAV? I searched here but there's a lot of content about Ambisonics formats and I didn't notice a specific discussion of my question.

I don't know when I'll want to hear Kontakte again, but I do have a few Nimbus cds that are probably also encoded. Thanks!
There are two possibilities for the material you describe.

1 - If it’s UHJ then it’s most probably the 2 channel matrixed type for which a standard UHJ processor is required, which extracts 3 channel (not the speaker feeds at this point) B-format signals that go inside the processor to regeneration of the 4 or 6 speaker signals (can be more but 6 is generally the most used).

2 - However, a pre decoded set of 4 speaker feeds can be derived from UHJ for a square rig, referred to as G-format, which is something Nimbus Records has done and released for a few recordings. Nimbus would have correctly applied the velocity and energy optimisations. I don’t know if any other companies did this conversion. I think the Nimbus ones were released on DVD-A discs and do not need decoding, just the correct ambisonic type speaker layout (a regular square of identical speakers).

Assuming a 2 channel UHJ source was used, its limitations are still there. Sadly, Nimbus did not keep its original native B-format recordings, from which a better than UHJ G-format could have been produced without the limitations of having to matrix. Also, it’s a shame no 3 and 4 channel UHJ encodings were ever released by anyone.

What details are there printed in the sleeve notes?
 

kfbkfb

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These might be helpful.


Kirk Bayne
 
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gene_stl

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I have a 1989 recorded CD "Sounds of Canterbury" by York Ambisonic. It mentions the "Minim" British made Ambisonic decoder and states that it can be played through a regular 2 channel stereo with good result. It seems to have been purchased at the Cathedral Gift Shop for ten pounds.
York CD 107
I don't at present have any way to decode it from CD stereo to four channel
 

SmcAustin

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I have a 1989 recorded CD "Sounds of Canterbury" by York Ambisonic. It mentions the "Minim" British made Ambisonic decoder and states that it can be played through a regular 2 channel stereo with good result. It seems to have been purchased at the Cathedral Gift Shop for ten pounds.
York CD 107
I don't at present have any way to decode it from CD stereo to four channel
Yes, my disc liner notes recommend the Minim as well, and also Audio+Design.
There are two possibilities for the material you describe.

1 - If it’s UHJ then it’s most probably the 2 channel matrixed type for which a standard UHJ processor is required, which extracts 3 channel (not the speaker feeds at this point) B-format signals that go inside the processor to regeneration of the 4 or 6 speaker signals (can be more but 6 is generally the most used).

2 - However, a pre decoded set of 4 speaker feeds can be derived from UHJ for a square rig, referred to as G-format, which is something Nimbus Records has done and released for a few recordings. Nimbus would have correctly applied the velocity and energy optimisations. I don’t know if any other companies did this conversion. I think the Nimbus ones were released on DVD-A discs and do not need decoding, just the correct ambisonic type speaker layout (a regular square of identical speakers).

Assuming a 2 channel UHJ source was used, its limitations are still there. Sadly, Nimbus did not keep its original native B-format recordings, from which a better than UHJ G-format could have been produced without the limitations of having to matrix. Also, it’s a shame no 3 and 4 channel UHJ encodings were ever released by anyone.

What details are there printed in the sleeve notes?
The recording is "UHJ encoded." Playback requires a decoder, defined as "a device with two inputs and four outputs," "four discrete audio amplifiers or two stereo amplifiers, preferably exactly matched" and "four discrete loudspeaker systems...exactly matched."

The Nimbus situation is confusing. The "Surround yourself with..." series is on DVD-A, but I understand most of their cds and lps are encoded.

Thanks for the replies!
 

stevendive

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Yes, my disc liner notes recommend the Minim as well, and also Audio+Design.

The recording is "UHJ encoded." Playback requires a decoder, defined as "a device with two inputs and four outputs," "four discrete audio amplifiers or two stereo amplifiers, preferably exactly matched" and "four discrete loudspeaker systems...exactly matched."

The Nimbus situation is confusing. The "Surround yourself with..." series is on DVD-A, but I understand most of their cds and lps are encoded.

Thanks for the replies!
In that case it looks like it’s a standard 2-ch UHJ recording you have. The rare Minim decoders might be found on auction sites but it’s easier to locate the recent Meridian DSPs (eg, the 565, 568.2, G61 series and G68 series), which all have ambi and super stereo processing built in. The G series boxes also have direct unmatrixed B-format inputs and all can output to 4 to 7 speakers.
 

gene_stl

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I am interested in the Meridian units for the above capabilities and also for their TriField processor which derives a center channel from stereo source material. Something on the future to do list.
 

stevendive

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I am interested in the Meridian units for the above capabilities and also for their TriField processor which derives a center channel from stereo source material. Something on the future to do list.
The Meridians are pretty good, from my experience. It would be just as well to check the firmware is the latest version as there have been improvements to TriField. You could go into meridianunplugged for discussion and advice on stuff like this.

Although I don’t use TriField much, due to practical considerations in my setup, it works well. It does need a little time to work out its best settings in your rig and the centre speaker really should be as similar as possible to your main LRs. A wider than 60 degrees LR spacing works well with TriField.

Meridian’s use of Trifield includes rears and/or sides if you have them, though these can be omitted, using something similar to the Haffler circuit. You can check how dramatic the delay and levels settings to rears and sides can be, too.

Have fun. Meridians have a shed load of adjustments to play with. The G series boxes can be set up with a Windows based configuration program and I think the 568.2 can still be used with a legacy program.
 

stevendive

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Yes, my disc liner notes recommend the Minim as well, and also Audio+Design.

The recording is "UHJ encoded." Playback requires a decoder, defined as "a device with two inputs and four outputs," "four discrete audio amplifiers or two stereo amplifiers, preferably exactly matched" and "four discrete loudspeaker systems...exactly matched."

The Nimbus situation is confusing. The "Surround yourself with..." series is on DVD-A, but I understand most of their cds and lps are encoded.

Thanks for the replies!
Just to add, Nimbus has an extensive back catalogue of ambisonic, mainly orchestral, recordings still available. CD serial number ranges 1700, 5000 and 7000 series are UHJ and there are a few sampler discs, too.

I have reservations about Nimbus ambisonic recordings, though. They used the Nimbus-Halliday native mic rig instead of a Soundfield mic. This NH rig is asymmetric and it looks like some shadowing of one mic capsule by another may be causing problems. I and someone I met both found the right-side imaging was poor. As neither of us had any idea we both had ambisonic rigs, we are reasonably confident we weren’t imagining things.

York and other recordings only seem to be available pre owned and I think they used Soundfield mics, which are symmetrical tetrahedral arrays.
 

jaybird100

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There are two possibilities for the material you describe.

1 - If it’s UHJ then it’s most probably the 2 channel matrixed type for which a standard UHJ processor is required, which extracts 3 channel (not the speaker feeds at this point) B-format signals that go inside the processor to regeneration of the 4 or 6 speaker signals (can be more but 6 is generally the most used).

2 - However, a pre decoded set of 4 speaker feeds can be derived from UHJ for a square rig, referred to as G-format, which is something Nimbus Records has done and released for a few recordings. Nimbus would have correctly applied the velocity and energy optimisations. I don’t know if any other companies did this conversion. I think the Nimbus ones were released on DVD-A discs and do not need decoding, just the correct ambisonic type speaker layout (a regular square of identical speakers).

Assuming a 2 channel UHJ source was used, its limitations are still there. Sadly, Nimbus did not keep its original native B-format recordings, from which a better than UHJ G-format could have been produced without the limitations of having to matrix. Also, it’s a shame no 3 and 4 channel UHJ encodings were ever released by anyone.

What details are there printed in the sleeve notes?
According to the sleeve, the two-channel audio tracks on the DVD-A discs are still UHJ-encoded, so that those who have a UHJ decoder (all one of you) can compare the decoded sound provided on the DVD-A tracks to those through the stand-alone decoder.
 

jaybird100

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UHJ is much closer to QS than it is to either H or UMX.
If you look at the chart on the back panel of the Surround Master, it even states the "Involve" (QS) mode is good for UHJ-encoded recordings. I've tried the SM with Matrix H, and with a UD-4 record to decode the basic matrix; it did OK, but I'm not convinced something wasn't missing.
 

stevendive

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UHJ is much closer to QS than it is to either H or UMX.
Only the matrixing part is similar, not the end to end use of spherical harmonic decomposition for soundfield reconstruction. Also, 2 ch UHJ (BHJ) has 3 matrixed signals in it, not 4 quad-like ‘discrete’ ones. Using a QS or other similar matrix decoders gives odd results.
 

J. PUPSTER

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Here's a list of decoders I found from @Mark Anderson's Ambisonic UHJ DiscographyAMBISONIC RECORDINGS 02-25-2014 VERSION 4.0b page.


Are there one or two of these that are considered the best overall for decoding the various UHJ forms?
 

Mark Anderson

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The list you are referring too has not been updated in years and is missing the Onkyo SV909 Receiver and Meridian gear. The Onkyo and Meridian would be the way to go as they are digital although the Onkyo at 50lbs is a beast if all you need is the decoder. That's the one I use on occasion
 
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surround.sound.enthusiast

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Here's a list of decoders I found from @Mark Anderson's Ambisonic UHJ DiscographyAMBISONIC RECORDINGS 02-25-2014 VERSION 4.0b page.


Are there one or two of these that are considered the best overall for decoding the various UHJ forms?
Decoders from the original era of Ambisonics are really quite rare to come up for auction, I've been looking for some time.
When I eventually get to a decoder I expect I'll be going the Meridian route.
 

kfbkfb

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A few years ago, I played my (UHJ encoded) Nimbus Classic Single [NI 1409] thru DPL 2 Music, I noticed that the "soundstage" in LF and RF was expanded, it sounded like the piano was right in the room with me (I don't recall anything specific about LB and RB, probably just ambience).

I am now playing this CD w/DPL (DPL 2 system isn't currently set up), not very impressive, very little from the surround channel.


Kirk Bayne
 

stevendive

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Here's a list of decoders I found from @Mark Anderson's Ambisonic UHJ DiscographyAMBISONIC RECORDINGS 02-25-2014 VERSION 4.0b page.


Are there one or two of these that are considered the best overall for decoding the various UHJ forms?
Minim AD series are very good. Meridian make them these days but the current ones are costly. I’d recommend used Meridian units (the 565, 568.2, G61 series and G68 series). Meridian ones are probably the best as the digital processing matrices are extremely accurately aligned.

The 568.2 is probably both the easiest to find and at a reasonable price. The G series are the most flexible, but still quite expensive, and can be set up via PC/Windoze (or in Mac OS using something like Parallels) using Meridian’s configuration program. Otherwise, setup is through a wizard on the units’ displays.
The list you are referring too has not been updated in years and is missing the Onkyo SV909 Receiver and Meridian gear. The Onkyo an Meridian would be the way to go as they are digital although the Onkyo at 50lbs is a beast if all you need is the decoder. That's the one I use on occasion
Hi Mark. This list is probably the least out of date I could find that has a good listing of ambi material and I admit I don’t often look at it as much these days. Meridian should be added if possible. Do you know whether anyone has charge of the article/list now?
Decoders from the original era of Ambisonics are really quite rare to come up for auction, I've been looking for some time.
When I eventually get to a decoder I expect I'll be going the Meridian route.
Those from the early days are indeed quite rare. Meridian is the only hardware maker currently making ambi decoders, which turn up in used hi-fi and auction sites.

If you don’t have anything against software decoders and the computer route then I think these may be around as plug-ins (VSTs, AUs etc). I will have to rummage around a bit…
 
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