Stereo versus surround sound

[skeptic]

What is your opinion?

When listening to music on a surround-sound system are missing something or gaining something as opposed to listening on a stereo-system.

As someone who has experimented with surround sound for almost 30 years and who has listened to a lot of live music both inside and outside of concert halls, it is clear that ordinary 2 channel stereo is very inadequate. The larger the hall would be for a given musical group, the greater the disparity between what a recording can offer under the best of circumstances and what you would hear live will be. Unfortuantely, modern multi channel systems developed for the home are entirely inadequate for reproducing concert hall acoustics which contribute so much to music.

If you think acoustics at a live performance are unimportant, consider that not only do acoustic architects and engineers get to spend tens of millions of dollars of other people's money to build rooms for listening to music, change them around, tear them down, and build them back up again, but one famous electrical engineer from MIT whose name inspires so much anger measured that a mere 19 feet from the performing stage at Boston Symphony Hall, America's acoustically best room for listening to music, the audience hears 89 percent reflected sound and only 11 percent direct sound and as you move farther back, the percentage of reflected sound continues to increase (this has almost nothing to do with his product.)

As for the bass from subwoofers, while it is true that a separate subwoofer can often increase both the loudness and range of bass, integrating it with the rest of a sound system to accurately reproduce music is not a particularly simple task. At the point where it crosses over to the rest of the system, there is evey likelihood that there will be major frequency response anomolies due to interference patterns. The best and most accurate loudspeakers for reproducing music have the woofers or subwoofers built into them in a way that indicates that the manufacturer has considered and dealt with this problem. Case in point, Bill's Teledyne AR9s.

[Geoffcin]

The best and most accurate loudspeakers for reproducing music have the woofers or subwoofers built into them in a way that indicates that the manufacturer has considered and dealt with this problem. Case in point, Bill's Teledyne AR9s.

While I have to agree with Skeptic that full range speakers always the best choice, for the most part they are much more expensive than a sat/sub system. A modern speaker with the frequency response of the AR9's would cost thousands. I think it's unnecessary for most HT application. i.e. If you want to listen to movie tracks, sat/sub is a good value.

HT is in the process of growing up now, while stereo is fully mature, and is specifically designed for High Fidelity sound reproduction, not music & movie sound. Does this make them incompatible? No, but it's going to take some time before engineers are able to understand the surround process enough to make the surround mix sound "better" than stereo. My guess is that there's going to be at least a 10 year learning curve, and we've only just started. There is great promise there though, and I see more and more of the quality names in hi-fi designing amps, and processors for HT.

Right now the only "surround" music that I prefer to stereo is live performance DVD's. The Eagles, "Hell Freezes Over", and Fleetwood Mac's "The Dance" come to mind.

[jbangelfish]

Well, I had the chance to hear another HT system the other day at a coworker's home. He's been bragging it up for months for both music and movies. First, he had to demonstrate a movie and it impressed me the way that all of these systems have. When a horse hoof hits the ground or a door closes, it sounds like a bomb went off. Throughout, there is a bass rumble which is unidentifiable noise. To me, real life does not sound anything like this. Maybe he has his bass turned up too far, I don't know but this is always the feeling that I get when I hear one of these systems.
Then he played a CD both in stereo and surround mode. It sounded best to me in stereo but I would not call it good, one sub, off to the right and stereo speakers in front, I can't get used to it and the sound quality just wasn't there. I'm sure there are systems that do it better but he has a fair amount of money into this, one of the biggest Yamaha HT receivers and all JBL speakers. Probably a middle of the road system but I'm in no hurry to go to this type of system.
I have heard of people using AR9's with HT but I'm in no hurry to try that either. The amp I'd want to adequately drive so many speakers would have to be too heavy for me to want to pick it up. The effect is nothing I'd strive for anyway. If I ever get into HT, it will be a small modest system that won't overwhelm me with unidentifiable bass sounds and it will be a completely separate system from my stereo.
The AR9's are the most accurate speaker that I have ever had and I am pleased in nearly all aspects of their sound. I don't sense the depth that I used to get with 901's but I have better accuracy. I think the reason is simple physics. I think Dr. Bose made an amazing discovery in the reflected sound principle and the little 901 is able to reproduce the depth of a concert hall better than any speaker that I have ever heard. Unfortunately, it is limited in how well it can do this by the small drivers, too small for the deepest bass and too large for the highest treble, especially when they have to do it all at once.
If someone were to combine the theories and principles of Bose and AR, they might have something really special. I intend to build something along these lines, just to satisfy my curiousity once and for all. As I said, it is simple physics, when you reflect most of the sound, there is a slight delay in the arrival. Call it a reverberation, echo, whatever you like but it gives the sound depth. It's fast enough that you don't hear it as echo or reverb and it does mimic a concert hall. I'm not aware of any other speaker system that utilizes this technology, some do it partially.
With any forward firing systems, all the sound arrives at the same time and to me sounds rather lifeless. There were some time array type systems in which some was delayed, I think Polk dabbled in this and Dahlquist but it's not the same as reflecting like what happens in a concert hall. I think Bose made one of the greatest discoveries in acoustic sound reproduction but in making an affordable system (and 901's are overpriced), he missed the whole package. You'd need loads of power to drive such a vast array of speakers but I for one, completely believe in the concept.
Bill

[Woochifer]

Well, I had the chance to hear another HT system the other day at a coworker's home. He's been bragging it up for months for both music and movies. First, he had to demonstrate a movie and it impressed me the way that all of these systems have. When a horse hoof hits the ground or a door closes, it sounds like a bomb went off. Throughout, there is a bass rumble which is unidentifiable noise. To me, real life does not sound anything like this. Maybe he has his bass turned up too far, I don't know but this is always the feeling that I get when I hear one of these systems.

Problems with bass can usually be blamed on room acoustics, which for a typical small to medium sized room will affect the overall sound much more in the low frequencies than in the midrange and highs. Boominess like what you observed is room induced peaking at specific frequencies caused by standing wave formation. In a lot of situations, these peaks can be upwards of 20 db or more, which can easily drown out other sounds and give you bass that's loud and overwhelming with certain sounds and empty otherwise. The only way around this is careful measuring of the in-room response and room treatments and/or parametric equalization.

The AR9's are the most accurate speaker that I have ever had and I am pleased in nearly all aspects of their sound. I don't sense the depth that I used to get with 901's but I have better accuracy. I think the reason is simple physics. I think Dr. Bose made an amazing discovery in the reflected sound principle and the little 901 is able to reproduce the depth of a concert hall better than any speaker that I have ever heard. Unfortunately, it is limited in how well it can do this by the small drivers, too small for the deepest bass and too large for the highest treble, especially when they have to do it all at once.
If someone were to combine the theories and principles of Bose and AR, they might have something really special. I intend to build something along these lines, just to satisfy my curiousity once and for all. As I said, it is simple physics, when you reflect most of the sound, there is a slight delay in the arrival. Call it a reverberation, echo, whatever you like but it gives the sound depth. It's fast enough that you don't hear it as echo or reverb and it does mimic a concert hall. I'm not aware of any other speaker system that utilizes this technology, some do it partially.

I think you're going at this from a flawed assumption. Just because concert halls have reverberant acoustics and scads of reflected sound does NOT mean that home speaker systems should try and emulate that. Why? Because the playback chain is different than a live performance. One is an actual event, the other is a reproduction of that event. If a recording already captures that reverberant effect from a live performance in a concert hall, the last thing you want is for the playback to add even more reverberation and echo.

And to me, that's the fatal flaw of the Bose direct/reflecting design. It sounds good in marketing literature, but it's not based on sound acoustic principles. The sound quality of the speaker itself with that design is dictated almost entirely on the distance from the walls, the room acoustics, the reflectivity of the surfaces, the placement, etc. Any asymmetries, odd shapes, open spaces, etc. will affect that type of speaker far more than with a direct firing speaker. The type of sound you get is much more unpredictable. And even when placed optimally, a direct/reflecting speaker introduces time domain errors and distortions that reduce dialog intelligibility, muddy up the imaging (because the head-transfer effects necessary to discern a three-dimensional sound image have to interpret smeared sounds), and have less than optimal tonal response.

There's a reason why mixing studios are soundproofed to minimize the reflected sound, why the best sounding movie theatres have acoustic controls in place to reduce the amount of echo, and why high end demo rooms are typically built with acoustic panels, bass traps, and other room treatments in place. Because a live sounding room will impose its own signature on top of what was already recorded. If the goal is to reproduce live sounds as accurately as possible, then any kind of alteration in the playback chain, whether that be an overly live sounding room or speakers that spray the sound in a random pattern, constitutes a distortion and deviation from that goal.

With any forward firing systems, all the sound arrives at the same time and to me sounds rather lifeless. There were some time array type systems in which some was delayed, I think Polk dabbled in this and Dahlquist but it's not the same as reflecting like what happens in a concert hall. I think Bose made one of the greatest discoveries in acoustic sound reproduction but in making an affordable system (and 901's are overpriced), he missed the whole package. You'd need loads of power to drive such a vast array of speakers but I for one, completely believe in the concept.
Bill

It may sound lifeless, but that very well may have been the intent of the recording engineer. Or it could be an overly dead sounding room, or the speakers were not placed correctly. If you're doing a blanket condemnation of all forward firing speakers and saying that Bose's approach is the correct way, then I think you're way off base. Bose is the only speaker company that takes the approach that they do, and I don't think it's because they know something that everyone else doesn't. Other manufacturers have tried to impart greater spatiality by tinkering with the phase relationships (which is what Polk did with their SDA speakers) or going with a bipolar design (forward and back firing drivers in phase with one another, which is very different from the almost random off-angle driver placements that Bose uses), using an omnidirectional driver, or simply designing a forward-firing speaker with a wide dispersion pattern. But, those designs are based on much more solid research than Bose's "discoveries." (Their marketing brochures look good, but their products are based on principles that predated them by decades)

[jbangelfish]

I don't think that there is anything random about what Bose designed. Change the angle, change the distance from the walls or turn them around and the desired effects are lost. Placement of the 901 is absolutely critical with very little adjustment available for different situations. Most people have never had them in the correct placement or had enough power to do them justice. Rest assured that a great deal of research went into their simple design. Dr. Bose is a highly regarded professor and either did or still does teach at MIT. He's ahead of most of us.
I do not want to alter a recording either, this is why I don't like equalizers and I have no tone controls. This leaves everything up to the recording engineers to get it right for me. If adding depth to the sound by strategically bouncing it out of corners is wrong, I guess I like being wrong. It creates a 3 dimensional image of sound better than anything that I have ever heard. The main flaw is a general weakness in the upper treble and a slight weakness in bass. They will reach 22hz which is lower than most high end speaker systems with 8 inch or even 12 inch woofers. If you ask me, it sounds better in person than it does on paper. I haven't read any of this stuff in years and I realize that the vast majority of audiophiles hate 901's. They can't do everything well but they do some things extremely well, mainly create a huge spatial sound experience.
Anyway, I'd take a pair of 901's over any HT system or multichannel system that I've ever heard anywhere, store demo or in a home. Overall, I'm happier yet with my AR9's, I just miss that depth of the 901. This is why I say that I'd like to build something that can do both accuracy and create the three dimensional quality achieved through direct reflection.
Don't worry, you won't change my mind. I'm old and stubborn and I've heard lots and lots of music live and recorded for my entire 51 years of life.
Bill

[Woochifer]

I don't think that there is anything random about what Bose designed. Change the angle, change the distance from the walls or turn them around and the desired effects are lost. Placement of the 901 is absolutely critical with very little adjustment available for different situations. Most people have never had them in the correct placement or had enough power to do them justice. Rest assured that a great deal of research went into their simple design. Dr. Bose is a highly regarded professor and either did or still does teach at MIT. He's ahead of most of us.
I do not want to alter a recording either, this is why I don't like equalizers and I have no tone controls. This leaves everything up to the recording engineers to get it right for me. If adding depth to the sound by strategically bouncing it out of corners is wrong, I guess I like being wrong. It creates a 3 dimensional image of sound better than anything that I have ever heard. The main flaw is a general weakness in the upper treble and a slight weakness in bass. They will reach 22hz which is lower than most high end speaker systems with 8 inch or even 12 inch woofers. If you ask me, it sounds better in person than it does on paper. I haven't read any of this stuff in years and I realize that the vast majority of audiophiles hate 901's. They can't do everything well but they do some things extremely well, mainly create a huge spatial sound experience.
Anyway, I'd take a pair of 901's over any HT system or multichannel system that I've ever heard anywhere, store demo or in a home. Overall, I'm happier yet with my AR9's, I just miss that depth of the 901. This is why I say that I'd like to build something that can do both accuracy and create the three dimensional quality achieved through direct reflection.
Don't worry, you won't change my mind. I'm old and stubborn and I've heard lots and lots of music live and recorded for my entire 51 years of life.
Bill

If your mind's made up, then that's fine. I have no problem that you like the 901s, I just happened to not like them or most of Bose's other products very much. I've heard the 901s many a time over the years, and I agree that the placement is crucial to getting them to sound right. But, so is the room configuration. I've not heard the 901s in an asymmetrical room, but I have heard other Bose direct/reflecting speakers in odd shaped rooms and the results are very inconsistent. The only shared trait from room to room is that the stereo imaging sound totally collapsed into the middle.

Dr. Bose might be an MIT trained engineer (I don't think he ever taught there, but he does hold a degree from there), but that doesn't mean that his approach supercedes all the other talented designers in the business. If anything, his talent has been matching decades-old design concepts with perceived gaps in the market. (I don't think anybody else would have thought that the market needed a $500 alarm clock or $1,200 boombox)

Even when done right, the 901s to me sound like "mono everywhere" because the imaging gets so smeared that I can't place from where the sounds are supposed to originate. It's a big sound yes, but some things are not meant to sound like they emanate from inside a giant concert hall, and the 901s tend to make everything sound like that. Also, I've never heard of anyone actually measuring the 901 to extend down to 22 Hz. Much like other Bose products, the 901 has a bump up in the midbass that can make them sound punchy, but that's not necessarily true full range extension.

The notion that the 901s can sound better than any surround setup does not make logical sense to me. The 901s can produce a larger soundfield than just about any two-channel setup out there, but in terms of creating a coherent soundfield encirclement, I just don't see it happening with the 901s, especially in a 5.1 setup. The 901's approach just runs contrary to how multichannel soundtracks are mixed and intended to get played back. With 5.1 movie soundtracks, the intelligibility of the center channel is essential for dialog clarity and seamless timbre matching with the mains. Having a center channel speaker that purposely distorts the time domain would be like listening to a movie in an old echoey theatre with no acoustic controls in place. (In that kind of setup, the most frequent reaction to a movie is usually, "What did they say?") THX certified movie theatres are required to construct a baffle wall behind the screen speakers specifically to maximize the time coherency of the audio, and control the reflected sound. In my own home setup, I put acoustic panels behind the front three speakers, and they substantially improve the overall coherency of the sound, smooth out some rough edges, and improve the image clarity.

In a timbre matched 5.1 setup using good speakers, proper placement, and a properly integrated subwoofer, the spatiality is huge but you don't lose the imaging coherency in the process. Not only can you place instruments and/or sound effect locations, but the front-to-back acoustic image and side imaging in particular are rock stable and very coherent. No two-channel setup I've ever heard can duplicate that. In a way, well done 5.1 setup gives you both accuracy and presence, and eliminates the need for a lot of the gimmickry that some speaker companies have deployed to get around the limitations of two-channel systems. Surround music is just getting started, and engineers are only beginning to learn how to work with the new tools. There are plenty of great examples out there already.

[jbangelfish]

I won't argue that. $450 clock radios and he's probably sold millions of them. I have never owned any Bose products other than 901's nor do I intend to. I have owned 4 different series of them and find the oldest two series to be the best. The series ones are about 35 years old and show no deterioration of any kind. They do seem to last. My son has a pair of 501's but I was never overly impressed by them and they do need repair.
What decades old concept in employed with the 901? Paper speakers? Wood cabinets? I don't see anyone else designing a full range direct reflecting speaker but I see many using it for a part of their system. I don't really know if it would work out or not, as I said, I intend to give it a try. The room has to have two perfect corners and nothing else. Too small and they'll overwhelm you, they need a pretty large area.
I have no idea what you listened to that gave you a mono everywhere effect. I have never heard greater separation or spatial response than from a pair or two pair of 901's. I have always appreciated this more from vinyl than CD, I don't know why. Yes, they sound big but IMO not too big. Listen to a grand piano at a church or concert hall, it sounds big. The same is true of a single voice in an acoustic structure, the idea is for everyone to be able to enjoy it. I've never been to a concert anywhere that sounded focal or small. It always sounds big to me. As for their ability to reach 22hz, you'd have to ask Skeptic. Something about working together and adding up their individual small dimentions to act as one large woofer. Sounds nuts but they will reach very low. The later series don't get much below 40hz but are ported and the bass sounds boomier, more ever present but won't go as low.
I know very little about the 5.1, 6.1, 7.1 etc. except that they exist and I haven't heard any that I like for music. I definately would not recommend the 901 for surround although some people use them this way. Quadraphonic albums were tried but never caught on. I guess not enough people wanted to go out and buy a whole new stereo. There might be some great sounding stuff being made with the new CD formats and surround type systems, I have not heard them and can't speak for or against them. What I have heard is two channel CD's played on 5.1 systems and didn't care for it.
I remain completely amazed at what can be done with two channel stereo and don't see a need for improvement or change. I like it all out in front of me (like a concert) and I like it to be difficult to tell where my speakers are. Better yet, I like to imagine that they are not even there and I get mighty close with two channel stereo.
Don't think that I'm calling the 901 the greatest speaker ever because I'm not doing that at all. I'm just saying that they create a depth and sense of spatiality better than anything that I've heard. They still have their shortcomings and I choose to listen to my AR9's.
Bill