Multichannel vs Stereo

[WmAx]

I disagree- sharing your own thoughts instead of parrotting the thoughts of others surely can't be censorship, can it? The former adds to a forum, the latter merely clogs it up.

Clogs up? Excuse me?

So, you would prefer I give all my own feeling and opinions, without referring to valid research and science or the view of highly respected scientists(which are based on factual research) to reinforce/support these? I'll make an exception on some things(like movies/music--non quantifiable things such as this) -- I made a post in the theatics forum with my opinons on a movie announcement -- for practice.

I'm not going to follow your last sentence or accept it as logical to apply to issues such as psychoacoustics and perceptual research and it's application toward technology. This place would just as well be called www.audioasylum2.com in that case. I can't believe you actually mean(clog the forum) this, to be honest.

-Chris

 

[WmAx]

For some reason the emotion figures are not working for you. The graphic is not as good as the actual faces

It's my browser(firefox). It's putting the emoticons at the end of the text, regardless of where I have the cursor. SO I just use the 'ol fashioned colon, dash and paranthees bracket.

-Chris

 

[markw]

And now, back to the original question.

I guess it all depends on what you want.

When I was a young ‘un, my rich uncle had the first color TV in my family’s circle of relatives and acquaintances. It was most certainly stunning, what with all the day glo colors and bright red faces. It was, um… interesting but not as much an improvement over black/white as I had imagined. I can still remember those Sunday night Bonanza’s in those colors. As time went on, others bought color TV’s and, much to my surprise, they were more subdued and did a much better job of capturing the reality of the scenes.

When I got a little older and bolder, I asked my uncle why his TV was set to such bright, unrealistic colors and his reply was that since he paid for color, he wanted to see as much as possible! …whatever.

I see this 2C/MC debate in the same way. I love live music. In fact, I have lots of it on both vinyl and aluminum. All of it 2 channel. Virtually all* of the music I’ve heard live has emanated from in front of me and that’s the way, uh huh uh huh, I like it. Of course, the venue imparts it’s own fingerprints by the reverberated ambiance it imparts to the overall sound and experience, particularly when we’re talking a cathedral type environment where delay times can be veeeeeeeeery looooooong.

Now, I have no great desire to hear music I’ve become familiar with remixed into more channels so I can be lost in a virtual musical experience. Perhaps others do, and more power to them. I’m sure there are many artists just lusting to re-re-re-release an old recording for a new audience (Pink Floyd, are you listening?) but hey, I’m sure even their 401K’s could use a boost.

Likewise, I’m not too sure I would be too impressed by new music created specifically for surround systems. Anyone old enough to remember Command Recordings such as Enoch Light’s Persuasive Percussion and their ilk? They defined the “ping pong” sound that was popular when stereo first became popular. Yeah, I’ve a few and while they are intriguing at first, they are musically empty in the long haul.

But, if new MC recordings could eschew the golly gee whiz bang temptation to throw music at me from all channels and use them simply to provide ambiance, such as to try to recreate the venue in which they (new recordings) were recorded, then I may find a whole new need for MC.

* One notable exception I can recall was a Paul Winter Solstice concert at The Cathedral of St. John The Divine where The opening organ peals resounded throughout the vomumiois space in there, trumpets blared from an overhead rear walkway and later, Mickey Hart was pulled, on a cart loaded with banging, clanging and thudding percussion, from the rear of the cathedral to the stage in the front.

 

[Rob Babcock]

No, I did mean you, WmAX. I was being overly dramatic anyway. I'm only saying that anyone can merely post a link to someone else's experiences and opinions. What I like about the forums is the chance to interact with "real" people. I can get dry facts from a million places.

Facts and info are of course a vital part of the online experience. I just hate to have it overshadow the fact that the majority of people participate in forums for the community if provides (and no, I have no stats to prove it. ). I dig hangin' with my "virtual buds" and hopefully learning a few things in the process.

Now, if I've sufficiently smoothed over the ruffled feathers, let's get back to something productive- like argueing over the merits of MC audio!

 

[Rob Babcock]

Odd, I ran a similar poll at AC and got pretty much the opposite result. Most of the guys there are die-hard 2Ch guys who think MC is a novelty or just for movies. There are a few of us MC guys, but I'm in the minority there.

I think their main problem is an inability to separate the medium from the content. They seem to think MC sucks because they don't like a sax or guitar blaring behind them. But naturally, SACD & DVD-A are simply mediums, and can be used well or used poorly, just like stereo CD & LP.

 

[Rob Babcock]

This is cool- Stereophile is reporting that many of the old Mercury 3 ch recordings are being released as 3 channel SACDs. Very interesting.

 

[WmAx]

Facts and info are of course a vital part of the online experience. I just hate to have it overshadow the fact that the majority of people participate in forums for the community if provides (and no, I have no stats to prove it. ). I dig hangin' with my "virtual buds" and hopefully learning a few things in the process.

I'm probably a lousy virtual buddy. But that's not my purpose or intent on a forum.

I apologize for steering this thread off topic. However, I felt that some important issues were brought up.

Facts and info are a vital part of all technology. Progress is achieved by using present knowledge to innovate/invent/improve. Not by randomly speculating and making up opinions that are based on nothing more then one's personal feelings.

I participate on internet forums, and in the process help(or attempt to help) people make logical decisions, form rational perspective and inform them of when others are just plain out full of B.S.. I certainly do not imply that I am error-free. I make errors just as anyone else.

I do not merely 'provide a link' as you seem to imply -- if you wish to search my username on www.head-fi.org or on this site or on any other site that I participate. However, I do often provide references of which my perspectives are based -- instead of the common alternative of making my cases on speculation, heresay(or links to speculation and heresay) and ignorance as is popular on some site examples listed below.

The result of no little to no interaction by people such as myself(unfortunately a relative large number of rational people woud be required to regulate a site such as headfi or asylum) and the plentiful(and welcomed) sharing of unsupported opinions?

http://www.audioasylum.com
http://www.head-fi.org
http://www.audioreview.com (recent policies added this week actualy prohibit my or anyone else's interaction providing objective viewpoints on any main forum -- so look for this place to sink to the level of the above two examples soon)

-Chris

 

[mtrycrafts]

I disagree- sharing your own thoughts instead of parrotting the thoughts of others surely can't be censorship, can it? The former adds to a forum, the latter merely clogs it up.

Nothing wrong with a good old fashioned personal opinion now and then. I'm sure letting a feeling slip or committing a hunch to paper (er, pixels) won't tear down the ivory towers of science!

May have not expressed myself well enough. Censorship, in audio at least, is when only a certaint point is allowed to be posted Certainly that is not the case here. That is why now I am here, not someplace else

That is what I was trying to get through but failed?

 

[Rob Babcock]

For the sake of clarity, speaking as a site moderator, the only thing we'll put the kay-bosh on here is spam posts, personal attacks and outright insults. Anything that crosses the lines of civilized behavior.

I PM'd you, WmAX. I'm not implying your posts & links are a waste of space. Sorry if you took it that way. But be aware that no one here will be required to "prove" anything. Anyone dissatisfied by that best get used to disappointment!

 

[Rip Van Woofer]

Tough for me to vote since I've yet to join the 21st century and thus lack direct experience; I hedged and went with #2. But it's obvious on a gut level that live music is a three-dimensional experience so you need more than two speakers to do it justice. Previously noted limitations of two channel are on the mark: narrow "sweet spot", unstable center image, etc.

Actually, the three channel Bell Labs experiments go back to the '30s! A "live" three-channel demo was given in (I think) Philadelphia with the source being a concert in (I think) D.C. sent by a hardwired feed using an experimental three-mic stereo setup (I have a reprint of the AES paper, but don't have it handy now). Anothe cool thing is that they had the curtains closed on the stage in Philly while the mics in DC were picking up the pre-concert noise of stagehands working, musicians taking their seats, etc. When the curtains were raised for the "concert" and the speakers were revealed on the otherwise empty stage the audience was quite startled, being convinced that the backstage activity they were hearing was actually happening there. If you go to the AES website and navigate to their "historical" section you can find & download the paper free as a pdf. Fascinating stuff. I think it was called "Experiments in Perception" or something like that.

I only have one Mercury Living Presence CD re-release (Paray and the Detroit Symphony doing various French composers), in two channel. Dang thing can still raise the hairs on your arms even though it was recorded about 40 years ago. I'd love to hear a three-channel release sometime. Meanwhile, I wonder if DPL2 would give a fair synthetic rendering of the original three-channel. Can't wait to find out.

Some years back in multichannel's infancy The Audio Critic did a two-part critical evaluation of the promise and likely reality of multichannel; also very interesting if you can find it. Much illuminating commentary on the dearth of actual psychoacoustic research to back up the marketing "enthusiasm". A "million" channels to do it really properly is probably about right! But even 5.1 is probably a decent start at least. Hard to imagine Holman's 10.x system finding a market beyond the wealthy!

 

[WmAx]

the dearth of actual psychoacoustic research to back up the marketing "enthusiasm". A "million" channels to do it really properly is probably about right! But even 5.1 is probably a decent start at least. Hard to imagine Holman's 10.x system finding a market beyond the wealthy!

Well, binaural(with prper custom HRTF curve for listener) implementations are obviously an exception to the million channel theory. Though, binaural is not practical for several reasons.

The 10.2 Holman system has the potential for very realistic perceived reproduction of space/ambience. This is not the same as auccrate repdoruction, which would imply that sounds could be localized//reproduced to sound exactly as they orginated in the orginal event. Something can sound real without having to sound 'exactly' like it did when recorded. Besides, thel listner has no frame of reference -- they were obviously not at the recording session.

As for expense, their actually is no need for it to be expensive(Holman system) to the pont of being only for the 'rich'. Look up some pioctures of the system -- most of the channels used in demos by Homal are small 2 way satillite units. An extremely high quality 2 way satellite is techncially possible to contstruct at low prices. The main cost is the cabinet, with such small cabinets it is easy/practical to build cabinets with minimal resonant behaviour in mass production.

-Chris

 

[Rob Babcock]

I'm not sure whether he really meant a million or was being facetious or serious, but he makes a good point. Of course, the WAF of a million speaker system (or perhaps 1,000,000.2 ) would be pretty low and the rig would be expensive!

10.2 would also be pretty spendy, at least if you bought 10 nice speakers. And placement could be a bear, too. But I'd sure jump on it if I could (assuming material existed to take advantage of it).

I'm anxious to listen to some of those reissued Mercury Living Presence 3 ch SACDs. There's some really good music there, and hopefully the sound will be great, too.

 

[Rip Van Woofer]

It's not just the cost of the speakers (even if it can be accomplished with modestly priced ones). It's the cost of the house/bachelor pad that would have the dedicated media room for all those speakers!

And I know that total accuracy is impossible; a good simulation of reality is all we can hope for.

On a purely unscientific level, I've often wondered what kind of multichannel system it would take do more than supply ambience and pass what I call the "Verdi Requiem test". Purely a product of my own imagination!

For those not up on classical music, wily ol' Giuseppe V., who knew a thing or two about dramatic impact, has a passel of brass players sneak around to the back of the hall (usually in the balcony) to let 'er rip during the "final trumpet of the last judgment" parts of his Requiem, thereby scaring the pants off the audience (and people think classical music is boring!). Now, even though brass doesn't have the low frequency component of, say organ and string basses (OK, maybe tuba but Verdi leaves them out of the "special effects"), it still takes good speakers to give both the "weight" and "bite" of brass for the proper terrifying impact. I think Berlioz used the same trick in his Requiem, too.

Would a 5.1 system do it? Probably not, not even with very good speakers for the rears in the usual to-the-side-and-back-a-bit position. Seems creating a center "phantom" image behind us with two speakers is psychoacoustially iffy. So...6.1? 7.1? 10.2? And how good do the speakers have to be? Better than little two ways with 4" woofers I'm guessing.

 

[WmAx]

. Now, even though brass doesn't have the low frequency component of, say organ and string basses (OK, maybe tuba but Verdi leaves them out of the "special effects"), it still takes good speakers to give both the "weight" and "bite" of brass for the proper terrifying impact. I think Berlioz used the same trick in his Requiem, too.

Weight and bite sound a bit too subjective too me. However, their is no reason that a well designed 6.5-7" 2 way with relative efficient high quality midbass can not produce amplitude peaks of nearly 110db/1meter at frequencies over 100 Hz with relatively little noticable distortion. Obviously, if you want to lower that frequency considerably, it will take something more then that. That is adequate SPL to scare the 'crap' out someone if presented as a sudden dynamic in the middle of a quiet passage. It's also an adequate lower limit to integrate reasonably well with 4th order L-R active crossovers to a rear subwoofer-- tough something along the lines of 70Hz would be more ideal(but we are trying to be practical here!).

And how good do the speakers have to be? Better than little two ways with 4" woofers I'm guessing.

True, 4" speakers would not be able to produce high enough SPL at low enough frequencies to even begin to integrate with a remote subwoofer adequately. I have my own little saying: I call that 'boseing' it.

-Chris

 

[Rob Babcock]

True, 4" speakers would not be able to produce high enough SPL at low enough frequencies to even begin to integrate with a remote subwoofer adequately. I have my own little saying: I call that 'boseing' it.

-Chris

But the kid at Best Buy told me their speakers are the best you can get!

 

[av_phile]

I chose "2" in the poll but I am not entirely sure that such a choice need to be made at all. I mean, listening at home provides nothing more than just a domestic "listening experience" out of a replica recording on a CD or vinyl or tape. Never the real thing. So if a listening experience is all that I want, there are excellent stereo recordings that give me as much thrill as listening to multichannel recordings. More from the latter as they provide a totally NEW listening experience. I know that panning the congas across all the channels is unrealistic, but it is a listening experience still. And the format is relatively new (or did they learn from the quadraphonic rage of the 70s?) so I welcome experiments in this format.

Many multichannel classical recordings I have in DTS and DVD-A confine the back channels to ambient sounds. While a number of mutlichannel POP and Jazz do contain discrete instruments at the back. The former is more realistic while the latter do give an immersive feel common in HT listening, as if you're in the middle of a performance. Not realistic, but a new listening experience.

What's nice about MC is the ability of some instruments to sound more detailed and present than in their former stereo mix. Thanks to sound engineers who have dedicated a channel for this or that instruments, allowing the many instruments to be spread across more channels. THis has the net effect of de-congesting a stereo recording where some instruments are often burried with the stronger sounding instruments. But it requires some degree of balancing act to ensure that the detail among the many instrumetns arrive simultaneosly at your ears. Otherwise, some can be more pronounced than necessary.

Do I need to choose between the two formats. I don't see the need. There are many excellent stereo recordings that do give unmistakable soundstage presence on their own. And there are new recordings in the MC format that are entirely engaging as well. With regards old stereo mixes re-mixed into MC, I have no problems with the specimens I have. Like I said in the preceding, they provide an entirely revealing playback. It is not so much the medium as the re-mix that make them so. I think studio engineers have learned a lot after all these years on the best way to optimize the digital recording and remixing process. A lot of stereo CD recordings I have remixed in DSD/SBM, HDCD, or 24-bit are done so well as to sound gorgeous in their new stereo releases. MC is just another re-mix. So it's possible there'd be lousy MC mixes as well. So far, I haven't encountered any in my modest but growing collection of DTS and DVD-A MC titles.

 

[djoxygen]

Would a 5.1 system do it? Probably not, not even with very good speakers for the rears in the usual to-the-side-and-back-a-bit position. Seems creating a center "phantom" image behind us with two speakers is psychoacoustially iffy. So...6.1? 7.1? 10.2? And how good do the speakers have to be? Better than little two ways with 4" woofers I'm guessing.

Being more often the predator than the prey (few vegetables have escaped my clutches), we're definitely designed to track things in front of us, and not behind. Also one of the reasons we can have our pants removed by a covert brass attack!

Another question the Verdi example brings to my mind: In a big concert hall, one might be able to directionalize low frequencies to a certain extent. With subs in our listening/HT rooms, we generally assume that the LF won't be localizable. WmAx brings up the possibility of a rear sub, so how big does a room have to be to identify the location of a LF source, or are there other factors that can make it localizable in a smaller room?

 

[WmAx]

Being more often the predator than the prey (few vegetables have escaped my clutches), we're definitely designed to track things in front of us, and not behind. Also one of the reasons we can have our pants removed by a covert brass attack!

Another question the Verdi example brings to my mind: In a big concert hall, one might be able to directionalize low frequencies to a certain extent. With subs in our listening/HT rooms, we generally assume that the LF won't be localizable. WmAx brings up the possibility of a rear sub, so how big does a room have to be to identify the location of a LF source, or are there other factors that can make it localizable in a smaller room?

Problems begin for any frequency when you seperate the integrating sources, exceeding the distance of approx. 1/2 the wavelength in air of the frequency(not a hard lined point, just a very loose approximate fraction). As you exceed this limit, the complex comb filtering effects are increased. For a mono base soruce and stereo main speakers, the problems are further enhanced if the subwoofer is not exactly spaced the same distance from each main speaker relative to the listening position. For distance reference, a 100Hz soundwave in air is approx. 11', a 50Hz wave approx. 22', etc.. The monitor speakers I was discussing would need to be steeply crossed at about 100Hz or to sufficiently produce the SPL levels we were disussing eariler. Besides the severe comb filtering problems, their would just not be anyway to match the phase at fc(crossover point) of the rear moniotors reasonbly with a subwoofer located in the front of the room with any reasonable degree. A lower crossover rate is still yet more optimal, but we were discussing 'practical' solutions, not ideal ones.

-Chris

 

[Gerald]

It's all depends of the original source. If the original master tape is stereo , it's better to leave it that way if not it will happen the same thing like the dreadful 60's long plays "Electronicly Processed to Stereo". In some case it's better to even leave it mono like "The Rolling Stones", "Herman Hermits" and "The Animals" sacds released recently.

I love to hear multichannel on sacd and dvd-audio as long there's nothing artificial or bad sense of of stage sound image.

 

[nm2285]

I've always enjoyed good old stereo due to budget and room constraints. However, I've never had the bug to upgrade to MC. I enjoy listening to the 2 channel soundstage and working with speakers in the imaging. Two channel will always stick for me, MC (IMO) has more of a place in movies. (I do have a sub with my 2 bookshelfs).

I do, however, wish there was more of a concentration on high-rez 2 channel albums. SACDs and DVD-A's primary focus is multichannel. I'd love a specific format for high-rez 2 channel.