Kreshna Aryaguna Nurzaman wrote:

Thoughts? Anyone? And could anyone explain the mystery of "surround information" being there in commercial stereo CDs, whose existence we've never realized until now?

Sounds like something similar to Prologic or some other matrix/HRTF wizardry. The "surround information" on stereo discs is only caused by phase differences between the left and right channel. QS and SQ vinyl records just used a standardized phase difference matrix to ensure repeatable results. With pure stereo records/CDs it's hit-and-miss, if the sound engineer accidentally mastered the track according to this matrix you can get some decent surround out of it.

jwt27 wrote:

Kreshna Aryaguna Nurzaman wrote:

Thoughts? Anyone? And could anyone explain the mystery of "surround information" being there in commercial stereo CDs, whose existence we've never realized until now?

Sounds like something similar to Prologic or some other matrix/HRTF wizardry. The "surround information" on stereo discs is only caused by phase differences between the left and right channel. QS and SQ vinyl records just used a standardized phase difference matrix to ensure repeatable results. With pure stereo records/CDs it's hit-and-miss, if the sound engineer accidentally mastered the track according to this matrix you can get some decent surround out of it.

Then the bigger the phase difference, the bigger the "surround effect"? Am I correct?

Well for games I think we better stay with ProLogic, but with music - especially for those who just like to preserve "fidelity", the Surround Master could work.

Isn't this just a fancy way of magnifying the effect of stereo panning? Thus any audio with the most extreme panning gets sent to the rear speakers and midway panning to the front speakers and no panning to the center speaker in a gradual fashion?

http://www.razerzone.com/gb-en/surround
maybe something similar in software?

Great Hierophant wrote:

Isn't this just a fancy way of magnifying the effect of stereo panning? Thus any audio with the most extreme panning gets sent to the rear speakers and midway panning to the front speakers and no panning to the center speaker in a gradual fashion?

I suspect so, although I still don't understand why it's much better dan Dolby ProLogic. Well at least the review says "Dolby ProLogic sounds anemic compared to the Surround Master".

By the way, isn't that what Dolby ProLogic also does? Creating surround sound from non-matrixed source using panning information?

There are difference though: DPL will upmix any stereo source (including non-matrixed stereo source) to surround, while with the Surround Master, whether surround sound would exist or not entirely depends on the source material. Perhaps SM works similar to DPL, but much more conservative?

Matth79 wrote:

http://www.razerzone.com/gb-en/surround
maybe something similar in software?

Could be, though the Surround Master seems to be entirely analog and "hard wired".

Kreshna Aryaguna Nurzaman wrote:

Could be, though the Surround Master seems to be entirely analog and "hard wired".

If it's entirely analog it's fixed function and probably not much different from "matrix circuits" or "stereo center circuits" that used to be popular ages ago (an example: http://kantack.com/surround/surround2.html#tag2diag1). Pro Logic may have some advantages as a result, as it's at least partially adjustable, and newer/more sophisticated technologies like CinemaDSP, Pro Logic IIx or IIz, LOGIC7, etc will have substantially more adjustability. 😊

As far as what Pro Logic actually does - the original design/intent was to re-play Dolby Surround material from VHS, Laserdisc, etc. Wikipedia has more detail: http://en.wikipedia.org/wiki/Dolby_Pro_Logic Essentially it's a decoder mode for select material, not a "noise on all channels" feature like Pro Logic II or LOGIC7. 😊

Pro Logic is fairly simple in terms of how it selects what gets put where, and channel separation isn't fantastic as a result. IMHO it isn't useful for pure mono/stereo recordings - but for properly encoded Dolby Surround material (which is mostly movies) it can be great (and note that with the advent of DVD and Dolby Digital, most players/decoders have an "Lt/Rt" output mode, which will send a signal that Dolby Pro Logic decoders can work with).

When the review says standard Pro Logic sounds "anemic" (and the marketing in the manual/site that says "restores lost detail") that has me thinking what SM is doing is some sort of matrix circuit, but it's also probably got some sort of "enhancer" or "exciter" in the path as well - so it's like stacking BBE and Pro Logic processors, or enabling CMSS + Crystalizer on a Creative card. It actually wouldn't sound bad as long as it's all done in reasonable proportions, but it isn't anything magical. Personally I'd rather have either the stand-alone BBE box (plus whatever matrix decoder) or the Creative card, because they both allow adjustment of their parameters. It'd also probably be more cost effective and you could go with balanced I/O (on the BBE 882i). Having said that, I generally don't like listening to stereo music through matrix decoders, I'd rather either just keep it in stereo (and what is so bad about that? just because your system has 400 speakers doesn't mean they all have to play all the time) or use an acoustic simulacrum like CinemaDSP. 😊

obobkivisch: thanks for the reply, interesting. So the SM is probably like the vintage quadraphonic receiver of old? The 1970 era?

By the way, the review actually mentions DPL II instead of DPL, does it change your hypothesis? An intriguing device nonetheless, and wonder why audiophiles tend to praise it while eschewing more common surround methods like CinemaDSP or DPL II. It could be snobbery though. 😁

Nonetheless, since I've bought a Yamaha, I think I'm going to use presence.speakers anyway! 😀 Have a pair of unused Phillips speakers around. Timbre-matching is not that critical for presence speakers, isn't it?

PS: I'm typing with an Android, hence no quotes. Got severe pain in my spine yesterday, and the doctor told me to lay straight on hard surface.

Kreshna Aryaguna Nurzaman wrote:

obobkivisch: thanks for the reply, interesting. So the SM is probably like the vintage quadraphonic receiver of old? The 1970 era?

By the way, the review actually mentions DPL II instead of DPL, does it change your hypothesis? An intriguing device nonetheless, and wonder why audiophiles tend to praise it while eschewing more common surround methods like CinemaDSP or DPL II. It could be snobbery though. 😁

With DPL-II it actually somewhat re-enforces my theory imho. Pro Logic I with material that lacks a lot of matrix information won't be much different from stereo playback unless the decoder is doing something it ought not be, and even with matrix material (e.g. a Dolby Surround encoded VHS) the bulk of the material will still be on the L/R speakers. PL-II is a bit different in that it tries to create 5.1 from any input, and with music IME usually ends up just dumping everything onto the center or LCR and killing the mid-range/mid-bass in the process. It's not a "good" effect imho. Running an exciter/expander alongside a more basic matrix decoder would very likely sound much more "alive" or "engaging" for music.

I'm not at all surprised folks eschew DPL II for music - I agree with that. For movies it can be beneficial depending on the source material - but it's still not perfect.

CinemaDSP is an odd duck in that it's both only available on Yamaha hardware, and has a number of different versions/variations depending on which hardware you have. For example CinemaDSP from the DSP-1, DSP-A1000, DSP-A3090, RX-V995, and RX-Z11 are all different beasts in terms of modes, features, channel input/output configuration, etc which can lead to different listening experiences and opinions. It's also chained to those kinds of components, so if someone doesn't have (or doesn't want) Yamaha equipment, they probably will never touch it. 😊

Nonetheless, since I've bought a Yamaha, I think I'm going to use presence.speakers anyway! 😀 Have a pair of unused Phillips speakers around. Timbre-matching is not that critical for presence speakers, isn't it?

In my experience, no it doesn't matter all that much. I don't even think they're full-range for the most part - I've had good results with fairly limited satellite speakers (that are probably over a cliff by 200-300 Hz). Placement and level matching are the more important criteria IME - make sure that the presence speakers are the right width and height relative to both your main L/R speakers and your seated position (refer to the owner's manual for a diagram, but in general they need to be higher up and wider apart than the L/R), and that you spend the few minutes with the level setting tone to get them relatively close to the L/R speakers. If they're run too hot they will overpower everything else, and it sounds bad, and if they're too quiet you don't get the effect and may not even notice when they're engaged.

I see, thans again. Interesting. I didn't know DPL I is quite conservative.in doing surround - unlike DPL Ii. Is DPL I still supported by modern receivers? IIRC most of them only supports DPL II and above (like DPL IIx and IIz), CMIIW.

I'm also curious about Quad receivers of the old days. I wonder what kind of (primitive?) surround algorithm they're using, if any.

Anyway, glad to know presence speakers doesn't have to be timbre-matched. Finally found.some use for my old Phillips speaker. And yes, I'll use presence speakers. In fact, the biggest tempting.factor to to pick the Yammie RX-V663 instead of Integra DTR 7.4 is actually Yamaha DSP and presence speakers instead of HDMI.

Kreshna Aryaguna Nurzaman wrote:

I see, thans again. Interesting. I didn't know DPL I is quite conservative.in doing surround - unlike DPL Ii. Is DPL I still supported by modern receivers? IIRC most of them only supports DPL II and above (like DPL IIx and IIz), CMIIW.

Honestly I don't know about current support - the newest receiver I actively use was built in 2000, and only supports DPL-I. I've seen and used newer receivers (say up to around probably 2010) and they all have a DPL-I mode but it may be "under" a more broad "Dolby" mode - where if the input is on a digital connection it will look for a Dolby Digital signal (and the Dolby Digital encode/decode can carry Dolby Surround - some receivers will show this as "3/1" or "3/0" or some other odd DD mode, some will just silently decode it), and either carry DS through that, or if it's switched to analog then engage Pro Logic I for whatever is coming in.

I'm also curious about Quad receivers of the old days. I wonder what kind of (primitive?) surround algorithm they're using, if any.

The only quad receivers I've ever seen just take separate front L/R and rear L/R inputs and would require a quad tuner or quad turntable to engage all the speakers in "true" quad, unless you just wanted mirroring of the front to back. I've read about stand-alone quad processors (for example Technics had one that looked like an oscope 🤣) but I've never seen one in the flesh, and my understanding is they're relatively rare these days. With the quad receivers I have seen with separate inputs for all channels, you can actually drop a DD or DTS decoder (or soundcard) that's capable of 4.0 output on them and use them for "modern" surround sound. Of course there's no subwoofer, center channel, etc and in some cases the "rear" amplifiers can be pretty abysmal (just like with early Pro Logic receivers), but it's probably more useful than "true quad" sources (I don't think there's any remaining quad radio stations and I don't think anyone has cut quad vinyl in decades).

Anyway, glad to know presence speakers doesn't have to be timbre-matched. Finally found.some use for my old Phillips speaker. And yes, I'll use presence speakers. In fact, the biggest tempting.factor to to pick the Yammie RX-V663 instead of Integra DTR 7.4 is actually Yamaha DSP and presence speakers instead of HDMI.

Looking fwds to review with games and movies. 😀

Kreshna Aryaguna Nurzaman wrote:

I'm also curious about Quad receivers of the old days. I wonder what kind of (primitive?) surround algorithm they're using, if any.

One of my friends is into this stuff so I know a bit about it. There are several different types of encoding schemes used for vinyl and reel-to-reel/8-track tapes. For vinyl, the most popular ones were QS, SQ and CD4. QS and SQ are just phase matrix encodings like ProLogic and this Involve surround decoder, and these were by far the most common. The matrices are slightly different though so they're not considered compatible.

My friend has a JVC CD-4 setup which is actually a discrete system, doesn't rely on phase differences and therefore has a much better channel separation. There are actually four different signals recorded on the disc, two normal stereo signals in the audio range (20Hz-15kHz), and two extra signals which contain the difference between the front and rear channels, encoded with frequency modulation outside the audio band (30kHz carrier frequency). To decode it you'll need an expensive cartridge with a shibata-shaped stylus that can track these higher frequencies, and a special CD4 decoder module.
You can actually play these records on a normal stereo system and you'll just hear the rear channels on front, like with the matrix systems (also with a phase difference, I think, so you'll still hear it behind you with a perfect stereo setup). But the high-frequency grooves wear out really fast when played with a normal stylus.
I really love how this system works. I mean, if you were trying to cram four audio channels into a stereo record while maintaining compatibility with stereo and mono systems... would you ever come up with this? 😮

Radio receivers used the same encoding schemes (both matrix and CD4), but radio broadcasts were short-lived and limited to USA only.

obobskivich wrote:

Kreshna Aryaguna Nurzaman wrote:

I see, thans again. Interesting. I didn't know DPL I is quite conservative.in doing surround - unlike DPL Ii. Is DPL I still supported by modern receivers? IIRC most of them only supports DPL II and above (like DPL IIx and IIz), CMIIW.

Honestly I don't know about current support - the newest receiver I actively use was built in 2000, and only supports DPL-I. I've seen and used newer receivers (say up to around probably 2010) and they all have a DPL-I mode but it may be "under" a more broad "Dolby" mode - where if the input is on a digital connection it will look for a Dolby Digital signal (and the Dolby Digital encode/decode can carry Dolby Surround - some receivers will show this as "3/1" or "3/0" or some other odd DD mode, some will just silently decode it), and either carry DS through that, or if it's switched to analog then engage Pro Logic I for whatever is coming in.

I see. What brand and model are you using?

obobskivich wrote:

I'm also curious about Quad receivers of the old days. I wonder what kind of (primitive?) surround algorithm they're using, if any.

The only quad receivers I've ever seen just take separate front L/R and rear L/R inputs and would require a quad tuner or quad turntable to engage all the speakers in "true" quad, unless you just wanted mirroring of the front to back. I've read about stand-alone quad processors (for example Technics had one that looked like an oscope 🤣) but I've never seen one in the flesh, and my understanding is they're relatively rare these days. With the quad receivers I have seen with separate inputs for all channels, you can actually drop a DD or DTS decoder (or soundcard) that's capable of 4.0 output on them and use them for "modern" surround sound. Of course there's no subwoofer, center channel, etc and in some cases the "rear" amplifiers can be pretty abysmal (just like with early Pro Logic receivers), but it's probably more useful than "true quad" sources (I don't think there's any remaining quad radio stations and I don't think anyone has cut quad vinyl in decades).

Ah, using the receiver as four-channel power amp. 🤣 Could be an interesting solution, especially since multichannel power amp is very expensive. And I don't get it. Sometimes the price disparity is so high that it's cheaper to use multiple stereo power amps instead.

obobskivich wrote:

Anyway, glad to know presence speakers doesn't have to be timbre-matched. Finally found.some use for my old Phillips speaker. And yes, I'll use presence speakers. In fact, the biggest tempting.factor to to pick the Yammie RX-V663 instead of Integra DTR 7.4 is actually Yamaha DSP and presence speakers instead of HDMI.

Looking fwds to review with games and movies. 😀

I can't wait to! 😀

jwt27 wrote:

Kreshna Aryaguna Nurzaman wrote:

I'm also curious about Quad receivers of the old days. I wonder what kind of (primitive?) surround algorithm they're using, if any.

One of my friends is into this stuff so I know a bit about it. There are several different types of encoding schemes used for vinyl and reel-to-reel/8-track tapes. For vinyl, the most popular ones were QS, SQ and CD4. QS and SQ are just phase matrix encodings like ProLogic and this Involve surround decoder, and these were by far the most common. The matrices are slightly different though so they're not considered compatible.

Interesting. where could I find more information about those? What does "QS" stand for?

jwt27 wrote:

My friend has a JVC CD-4 setup which is actually a discrete system, doesn't rely on phase differences and therefore has a much better channel separation. There are actually four different signals recorded on the disc, two normal stereo signals in the audio range (20Hz-15kHz), and two extra signals which contain the difference between the front and rear channels, encoded with frequency modulation outside the audio band (30kHz carrier frequency). To decode it you'll need an expensive cartridge with a shibata-shaped stylus that can track these higher frequencies, and a special CD4 decoder module.

Even more interesting. Is that a brand-specific discrete system? (instead of more common standards like DD)

jwt27 wrote:

You can actually play these records on a normal stereo system and you'll just hear the rear channels on front, like with the matrix systems (also with a phase difference, I think, so you'll still hear it behind you with a perfect stereo setup). But the high-frequency grooves wear out really fast when played with a normal stylus.
I really love how this system works. I mean, if you were trying to cram four audio channels into a stereo record while maintaining compatibility with stereo and mono systems... would you ever come up with this? 😮

Radio receivers used the same encoding schemes (both matrix and CD4), but radio broadcasts were short-lived and limited to USA only.

I see.

It's interesting to know more about the history of surround sound. It seems there were several tried surround methods that have "lost in time", especially after the rise of popular standards like Dolby and DTS.

Quad channel is probably 1970s things, but I still remember early 3D sound card like Diamond MonsterSound 3D. Those Aureal 3D sound cards also opted for quad channel instead of 5.1.

Kreshna Aryaguna Nurzaman wrote:

Interesting. where could I find more information about those? What does "QS" stand for?

QS stands for "Quadraphonic Sound", SQ is "Stereo Quadraphonic", and CD-4 is "Compatible Discrete Four".
I think the wikipedia page on quad surround sums it up pretty well. But the best place to find more in-depth information, according to my friend, would be the QuadraphonicQuad forums. In fact, I just had a quick look and it seems there's much talk about the Involve Audio Surround Master (and similar decoders) there as well.

Kreshna Aryaguna Nurzaman wrote:

Even more interesting. Is that a brand-specific discrete system? (instead of more common standards like DD)

Yes, CD-4 was a proprietary system developed by JVC. This was the most successful discrete channel system for vinyl records, though could still be considered a flop, especially when compared to nowadays' 5-channel formats.

Kreshna Aryaguna Nurzaman wrote:

I see.

It's interesting to know more about the history of surround sound. It seems there were several tried surround methods that have "lost in time", especially after the rise of popular standards like Dolby and DTS.

Quad channel is probably 1970s things, but I still remember early 3D sound card like Diamond MonsterSound 3D. Those Aureal 3D sound cards also opted for quad channel instead of 5.1.

Yes, many early PCI surround sound cards offered 4-channel audio. I think 5-channel surround only got going after DVDs became more common.

jwt27 wrote:

Kreshna Aryaguna Nurzaman wrote:

Interesting. where could I find more information about those? What does "QS" stand for?

QS stands for "Quadraphonic Sound", SQ is "Stereo Quadraphonic", and CD-4 is "Compatible Discrete Four".
I think the wikipedia page on quad surround sums it up pretty well. But the best place to find more in-depth information, according to my friend, would be the QuadraphonicQuad forums. In fact, I just had a quick look and it seems there's much talk about the Involve Audio Surround Master (and similar decoders) there as well.

Thanks for the links. I've been browsing the forum and found many interesting things.

jwt27 wrote:

Kreshna Aryaguna Nurzaman wrote:

Even more interesting. Is that a brand-specific discrete system? (instead of more common standards like DD)

Yes, CD-4 was a proprietary system developed by JVC. This was the most successful discrete channel system for vinyl records, though could still be considered a flop, especially when compared to nowadays' 5-channel formats.

Indeed. Many quadraphonic attempts in the past have lost their popularity to Dolby and DTS.

I personally prefer full range mains instead of small mains with a "sub", but it seems .1 formats (5.1, 7.1 etc) has become more popular because small mains with "sub" is cheaper, more accessible to the public.

jwt27 wrote:

Kreshna Aryaguna Nurzaman wrote:

I see.

It's interesting to know more about the history of surround sound. It seems there were several tried surround methods that have "lost in time", especially after the rise of popular standards like Dolby and DTS.

Quad channel is probably 1970s things, but I still remember early 3D sound card like Diamond MonsterSound 3D. Those Aureal 3D sound cards also opted for quad channel instead of 5.1.

Yes, many early PCI surround sound cards offered 4-channel audio. I think 5-channel surround only got going after DVDs became more common.

It's interesting to note that early 3D sound (4.0) would fit perfectly with 1970s vintage quad receiver. 🤣

I still prefer 4.0 though. It works with vintage quad recordings, it works with most Aureal 3D cards, and it still works with modern 5.1 or 7.1 systems since most AV receivers can downmix to 4.0.