or Connect
Head-Fi.org › Forums › Equipment Forums › Sound Science › Blu-Ray Audio: The latest gimmick?
New Posts  All Forums:Forum Nav:

Blu-Ray Audio: The latest gimmick? - Page 7

post #91 of 129
Quote:
Originally Posted by xnor View Post
 

With a center channel you get a real center that is more stable, accurate and sounds better

 

You can also move the mains further apart, creating a larger aural image/soundstage. That's important if the system doubles for movies. My screen is ten feet wide. My towers in the rear are on either end of the screen. The studio monitors are a little further out into the room and are about six feet wider apart. Without the center channel behind the screen, there would be a huge gaping hole in the middle.

 

The other day, I played the blu-ray of Billy Rose's Jumbo. At the beginning, the first image is of a proscenium stage. A character walks on stage from the right speaking, and crosses to the other side and exits left. As I watched it, the voice of the character followed him across the screen with pinpoint accuracy, not changing the sound at all as it handed off from channel to channel to channel- about 15 feet from right to left. Even with an off axis listening position, it was still startling. If it is capable of doing that with complete precision, you can guess how well it handles soundstage in music.


Edited by bigshot - 11/14/13 at 10:44am
post #92 of 129
Quote:
Originally Posted by xnor View Post
 

Disagree. The phantom center produced by a stereo setup definitely has its flaws. First, the room and the listeners distance to each speaker has to be absolutely symmetrical in order for dual mono to be perceived dead on center.

Secondly, comb filtering is a physical necessity with stereo. When both speakers play the same signal, the sound of the right speaker will arrive slightly delayed at the left ear and vice versa. This results in multiple frequency response dips (comb filtering). That's one reason why stereo sounds crap if there are no reflections from the room (they partly fill in the comb filtering gaps).

 

With a center channel you get a real center that is more stable, accurate and sounds better (flatter FR).

OK, maybe I should have said: "Under normal circumstances there should be very little perceivable difference when an image is positioned in the phantom centre", rather than there shouldn't "even be the slightest loss". I never stated there were no problems with stereo. Obviously there are flaws with stereo and in creating a phantom image, especially in a larger space and if not sitting in a line central to the speakers, as indeed I alluded to in my last post! However, I was addressing what bigshot stated and restated in his last post that without a centre channel he has "a huge gaping hole in the middle". While stereo does have it's imaging flaws, you should not have a huge gaping hole in the middle or anything even remotely similar to a huge gaping hole, so there is patently something seriously wrong with bigshot's system.

 

While 5.1 system does solve some the problems of the phantom centre in 2 channel stereo, it also introduces other stereo image problems because in the front you now have two smaller stereo soundfields instead of one large one, plus a stereo soundfield between the left and right rear speakers and other stereo images between each of the rear speakers and each of the front speakers. So, with the centre channel in 5.1 you solved one stereo problem but you've also introduced a whole bunch of new stereo imaging problems which, requires an even more precise listening position than stereo. The problem of a tiny "sweet spot" in 5.1 is reduced in cinemas by diffusing the soundfield using an array of (diffuser) speakers, which is why in a cinema you see 20 or more speakers all around the rear and side walls, rather than just two speakers in the rear left and right positions but of course that doesn't happen in a home 5.1 system. I'm surprised you didn't realise this or failed to consider it when you were disputing what I was saying about stereo in relation to 5.1!

 

Quote:
Originally Posted by bigshot View Post
 

Maybe it's magic. Come by and I'll play it for you and you can tell me why it sounds so good when it shouldn't!

I didn't say your room sounded good when it shouldn't, just apparently better to you relative to the obviously horrendous issues you've got with your front left and right speakers. In my opinion there is a massive gap between "better than horrendous" and "so good" but it's your room and you are obviously happy with it, so that's all that matters (to you).

 

BTW, you can use the old audiophile response when their beliefs are questioned, that science (acoustics in this case) doesn't know what it's talking about but you do and what's really happening must be some form of magic. That is if you don't mind sticking your head above the parapet and going against all the principles of acoustics which incidentally are employed in every concert hall, every cinema, every commercial recoding studio and every dubbing theatre. To be honest, your response is disappointing. From many of the other threads in which you have participated, I expected more from you than the old audiophile resort of "maybe it's magic". I also suggest your response would be more appropriate in one of the other, audiophile, forums than here in the sound science forum.

 

G


Edited by gregorio - 11/14/13 at 1:23pm
post #93 of 129

Well I agree that there shouldn't be a gaping hole in the middle with stereo.

 

Quote:

Originally Posted by gregorio View Post
 

While 5.1 system does solve some the problems of the phantom centre in 2 channel stereo, it also introduces other stereo image problems because in the front you now have two smaller stereo soundfields instead of one large one, plus a stereo soundfield between the left and right rear speakers and other stereo images between each of the rear speakers and each of the front speakers. So, with the centre channel in 5.1 you solved one stereo problem but you've also introduced a whole bunch of new stereo imaging problems which, requires an even more precise listening position than stereo.

Well no.

With a Dolby or ITU 5.1 setup (30° to front, 110° to rear speakers) you have quite a big sweet spot. Most importantly, the sweet spot is not a narrow line.

 

You do not get smaller stereo sound fields in the front. You get one bigger, more well-defined sound field, especially in the center. Instead of a 60° distance between speakers where problems occur in the middle you now only have 30°. Put it simply: if you put your stereo speakers at +/- 15° you'd get closer to the advantages of the front channel setup in 5.1 (still no perfect center though which is arguably the most important area), with the difference that you'd have a very narrow sound field and other problems.

 

The rear channels are not supposed to give you perfect imaging for sound sources at +/- 90° or even 180° behind you, far from it. That's also the reason why usually you won't find precisely locatable stuff encoded in the rear channels. This also makes this point irrelevant, and the tiny sweet spot comment is nonsense anyway since we're comparing to stereo in a living room here:

Quote:
 The problem of a tiny "sweet spot" in 5.1 is reduced in cinemas by diffusing the soundfield using an array of (diffuser) speakers, which is why in a cinema you see 20 or more speakers all around the rear and side walls, rather than just two speakers in the rear left and right positions but of course that doesn't happen in a home 5.1 system. I'm surprised you didn't realise this or failed to consider it when you were disputing what I was saying about stereo in relation to 5.1!

Edited by xnor - 11/14/13 at 2:09pm
post #94 of 129
Quote:
Originally Posted by gregorio View Post
 

I didn't say your room sounded good when it shouldn't, just apparently better to you relative to the obviously horrendous issues you've got with your front left and right speakers. In my opinion there is a massive gap between "better than horrendous" and "so good" but it's your room and you are obviously happy with it, so that's all that matters (to you).

 

I remember you saying that I shouldn't tell you that you would like the sound of my system because I don't know what you've heard. Well, I know one system you haven't heard... mine!

 

Do you have a 5:1 system in your own home?

post #95 of 129
Quote:
Originally Posted by xnor View Post
 

Well I agree that there shouldn't be a gaping hole in the middle with stereo.

 

With the speakers 17 feet apart and the listening position about 10 to 12 feet back? You just can't do a spread that wide with 2 channel without getting a hole in the middle!

post #96 of 129
Quote:
Originally Posted by bigshot View Post

 

With the speakers 17 feet apart and the listening position about 10 to 12 feet back? You just can't do a spread that wide with 2 channel without getting a hole in the middle!

Okay well that's a different story.

(I was thinking of a more classical +/- 30° stereo setup.)

post #97 of 129

This thread seems to have developed into a system set up topic ! Has anyone actually bought these discs, and if so, what are your thoughts on them ?

post #98 of 129

I have many great blu-ray music disks with the exact same kind of audio as this. They sound great, the native 5:1 ones are best. The 2 channel ones sound exactly like CDs (which is pretty darn good in my book!)

post #99 of 129
Quote:
Originally Posted by xnor View Post

With a Dolby or ITU 5.1 setup (30° to front, 110° to rear speakers) you have quite a big sweet spot. Most importantly, the sweet spot is not a narrow line.

 

You do not get smaller stereo sound fields in the front. You get one bigger, more well-defined sound field, especially in the center. Instead of a 60° distance between speakers where problems occur in the middle you now only have 30°. Put it simply: if you put your stereo speakers at +/- 15° you'd get closer to the advantages of the front channel setup in 5.1 (still no perfect center though which is arguably the most important area), with the difference that you'd have a very narrow sound field and other problems.

In theory what you are saying is correct under certain circumstances, circumstances which are frequently not met. In large cinemas, you still end up with large and problematic stereo soundfields between the centre and left and right speakers, which is why theatrical 7.1 was invented, to provide 5 front speakers which include a centre left and centre right. This is obviously not such an issue in a home 5.1 setup, instead home setups suffer from other practical issues, where to put the centre channel for example. The vast majority of home setups do not use AT screens, instead the centre channel is placed above or below a flat screen panel or projection screen (and therefore on a different horizontal plane from the other speakers) and commonly employ a different, smaller speaker for the centre channel relative to the left and right speakers. Home users also frequently fail to appropriately delay the output to the centre channel. Additionally, in practise a stereo soundfield which includes the centre speaker is often avoided in domestic 5.1 mixes. In practise, music and stereo effects frequently still use the left and right speakers (with a phantom centre), with mainly just dialogue and Foley routed to the centre channel. In fact, some TV networks specify only dialogue in the centre speaker and a phantom centre for everything else. Add all these facts up and the ideal of the perfectly smooth stereo soundfield which solves the phantom centre issues is usually not the reality in practice!

 

Quote:
Originally Posted by xnor View Post

The rear channels are not supposed to give you perfect imaging for sound sources at +/- 90° or even 180° behind you, far from it. That's also the reason why usually you won't find precisely locatable stuff encoded in the rear channels.

This is a more complex subject to deal with because it deals with creative uses and the application of processes during mixing. Many senses your statement is kind of backwards. One of the reasons why you don't find as much precisely locatable sounds to the side and in the rear channels in many movies as you do in the front is because of the imaging problems. However most of what is put in the rear speakers does contain a coherent image but at relatively low levels where lack of accuracy in the rear and side stereo images is not so critical. In other words, you would get a better result if the side and rear stereo images were more stable, this is why Dolby EX was invented many years ago, to provide a more focused rear stereo image but EX (and the DTS equivalent) is not very commonly in domestic setups. It is also one of the fundamental design concepts of newer systems like Dolby Atmos. It would seem rather strange to invent systems which attempt to solve stereophonic problems inherent in surround sound, if as you state those problems do not exist in the first place!

 

G

post #100 of 129
Quote:
Originally Posted by bigshot View Post
 

I have many great blu-ray music disks with the exact same kind of audio as this. They sound great, the native 5:1 ones are best. The 2 channel ones sound exactly like CDs (which is pretty darn good in my book!)

...but do you own any of the HFPA discs ?

post #101 of 129
Thread Starter 
I think I should change the title...

How's "Blu-Ray/HD audio: the ultimate setup guide" ?
post #102 of 129
Quote:
Originally Posted by Rob49 View Post
 

...but do you own any of the HFPA discs ?

 

 No, mine all have pictures... but I have music disks with TrueMaster audio or whatever format these are in. To be honest, blu-ray audio is MUCH more convenient for me than SACD multichannel. I'd buy music in this format, but the price would have to be comparable to CDs and the running time should take advantage of the storage capability of the disk.

 

For instance, they recently came out with a blu-ray disk of Solti's Ring of the Nibelung. The advantage of having 17 hours of uninterrupted sound is very attractive for opera. If I didn't already have it on CDs, I would have been interested in it.

 

The mysterious PHANTOM CENTER is not a problem with Yamaha's 7:1 Stereo DSP, because it puts material common to both right and left in the center, so the soundstage can be wider without having any dip in the middle.

 

Rear channels are almost always just phase information that keeps the rear alive and gives presence to the room. It only gets actual sound in goofy scifi movies.


Edited by bigshot - 11/15/13 at 10:08am
post #103 of 129
Quote:
Originally Posted by proton007 View Post

I think I should change the title...
How's "Blu-Ray/HD audio: the ultimate setup guide" ?

 

Ha! I think I'm the only one here who has actually done it!

post #104 of 129
Quote:
Originally Posted by bigshot View Post
 

 

 but the price would have to be comparable to CDs and the running time should take advantage of the storage capability of the disk.

 

Prices from Universal's U.K. website are £16.99 + £1.99 postage. Regards storage capacity, Universal state how much you can get on one disc, but if they don't carry that out, by putting more content on them, then their claims & boasts mean nothing !!

post #105 of 129
Quote:
Originally Posted by bigshot View Post
 

Do you have a 5:1 system in your own home?

 

Not at this instant because I've just moved but I have had several 5.1 systems at home over a period of about 8 years. That's rather immaterial though as I work as an audio post professional in a commercial 5.1 studio. My first 5.1 theatrical feature was released in 1999 but I'd worked with LCRS surround on TV for a few years prior to that. It's because I do it for a living and have done so for about 15 years, that I can say with complete confidence that this following quote of yours is utter BS: 

Quote:

Originally Posted by bigshot View Post Rear channels are almost always just phase information that keeps the rear alive and gives presence to the room. It only gets actual sound in goofy scifi movies.

I mean where do you get this stuff from? Do you think to yourself, "I know, let's screw with anyone thinking of getting a home cinema system by making some stuff up that's completely wrong and maybe if I post it in the sound science forum it will appear more believable"? I just don't get the point of posting something like this.

 

Quote:
Originally Posted by bigshot View Post
 

The mysterious PHANTOM CENTER is not a problem with Yamaha's 7:1 Stereo DSP, because it puts material common to both right and left in the center, so the soundstage can be wider without having any dip in the middle.

 

Just because you don't know what it is does not make it mysterious! It's essentially the basis of stereophonic sound. And it's not a problem, except apparently for you because you have deliberately setup your system so that it doesn't work correctly. So of course Yamaha's 7.1 DSP will sound better than your stereo, anything will sound better than your stereo because you've deliberately broken it!! You don't happen to work for Yamaha by any chance do you?

 

G

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sound Science
Head-Fi.org › Forums › Equipment Forums › Sound Science › Blu-Ray Audio: The latest gimmick?