Surround sound: diminishing returns? (Random musing)

[MartinX]

This probably isn't a new idea to many of you.

My circumstances have been such that an earth shaking speaker set up isn't really viable (for social reasons), so I have to do most of my music listening/gaming through headphones, which is fine.

However, I have had a set of logitech z680s for a couple of years and a recent change in circumstance means I have a window when I can use speakers without waking/pissing off anyone, so I dusted them off and set them up.

I recall when 5.1 was taking over from 4.1 one or two reviews saying that the extra speaker didn't actually add much, and when 6.1 started coming out, similar comments were made, but I didn't pay much attention.

I bring this up, because I'm sitting in front of my PC listening to some music with only the left and right front speakers and the sub generating any noise, and I swear there's a strong centre front noise coming at me, it's so clear that I actually had to disconnect the centre speaker to make sure the sound wasn't coming from there.

I've been fiddling around with various output modes and having the centre front speaker on or off makes no difference at all to the sense of direction of the sound.
Vocals are still right in the middle, and sound like they're coming out of my monitor!

So, the point?

Why did we need to go higher than 4.1 again?

I was considering getting a set with more satellites to take better advantage of my A4pros capabilities, but all of a sudden I'm thinking I didn't even need the 5.1 to get brilliant surround sound, and that I'd be paying a high premium for a marginal (if even) improvement.

 

[BO(V)BZ]

You are forgetting the value of a strong center channel for movies. I admit that you can get away without one for games easily enough, and IMO music should be listened to with the original number of channels it was recorded in, but a center is indispensible for movie watching. While speakers may image very well, they certainly can't entirely replace a discrete speaker. Additionally, the center channel receives by far the greatest percent of a movie's soundtrack, along the lines of 70% of all sound. If you axe that speaker, you have to matrix out the sound to the LR's, which can only be inferior.

Also, multichannel music depends on a center, so if you have ever any plans to listen to DVD-A or the like, you would be shortchanging yourself by not purchasing a center.

If movies and multichannel music don't do anything for you, that's understandable, but if they are remotely important, a discrete center is a must for them.

 

[MartinX]

You are forgetting the value of a strong center channel for movies. I admit that you can get away without one for games easily enough, and IMO music should be listened to with the original number of channels it was recorded in, but a center is indispensible for movie watching. While speakers may image very well, they certainly can't entirely replace a discrete speaker. Additionally, the center channel receives by far the greatest percent of a movie's soundtrack, along the lines of 70% of all sound. If you axe that speaker, you have to matrix out the sound to the LR's, which can only be inferior.

Also, multichannel music depends on a center, so if you have ever any plans to listen to DVD-A or the like, you would be shortchanging yourself by not purchasing a center.

If movies and multichannel music don't do anything for you, that's understandable, but if they are remotely important, a discrete center is a must for them.

It's mostly academic because 5.1 is pretty much all you can buy anyway, and obviously if the track is mixed with a centre channel then you can't do without it.
But I find myself taken aback by the very strong, clear sense of centre positioning I'm getting with just the stereo speakers and wondering if a discrete centre channel actually makes that much difference over well mixed 2x2.

It's kind of hard to test.

 

[GodsMadClown]

You've discovered what I've been thinking (and occasionally saying) for some time now. A center channel isn't needed for a typical computer rig.

The traditional job for a center channel is to anchor the dialog of a movie to the screen for multiple listeners. Imagine if you have multiple listeners, perhaps 4 people seated on a sofa.

            screen  
          l    c    r



       Sofa-x-x-x-x-Sofa    
   sl                     sr

x = listener

Each of those listeners is going to have the dialog localized right at the screen. However, how many listeners are there in a traditional computer situation? That's right. One. A phantom center is just fine.

 

[SilverMK3]

You've discovered what I've been thinking (and occasionally saying) for some time now. A center channel isn't needed for a typical computer rig.

The traditional job for a center channel is to anchor the dialog of a movie to the screen for multiple listeners. Imagine if you have multiple listeners, perhaps 4 people seated on a sofa.

            screen  
          l    c    r



       Sofa-x-x-x-x-Sofa    
   sl                     sr

x = listener

Each of those listeners is going to have the dialog localized right at the screen. However, how many listeners are there in a traditional computer situation? That's right. One. A phantom center is just fine.

For music listening and occasional gaming, stereo imaging should be fine (assuming proper speaker placement). For watching DVD movies or listening to multichannel audio, though, you're going to be downmixing the discrete center and surround tracks to your L and R channels - most likely ruining your sound stage in the process.

Get 5.1 speakers if you're going to be listening to 5.1 soundtracks. Get nice 2.0 or 2.1 speakers if you're going to be listening to stereo sources (music).

 

[MartinX]

For music listening and occasional gaming, stereo imaging should be fine (assuming proper speaker placement). For watching DVD movies or listening to multichannel audio, though, you're going to be downmixing the discrete center and surround tracks to your L and R channels - most likely ruining your sound stage in the process.

Get 5.1 speakers if you're going to be listening to 5.1 soundtracks. Get nice 2.0 or 2.1 speakers if you're going to be listening to stereo sources (music).

That's not the point though, I reckon that the centre channel actually doesn't give much, if any benefit, and didn't really need to exist in the firstplace, except in the circumstances that Godsmadclown illustrated.

Obviously the optimal output set up is the one that the track is designed for (probably) but I was looking a step before that.

It was more of an observation than the starting point for a debate.

 

[mustang_steve]

There are a fwew reasons why surround for a PC is useless beyond 5.1

First is soundfield....in a nearfield environment there is just too short of a distance from the course to your ears to determine direction properly...there fore you can make a convicning surround with as little as THREE speakers (using psycho-acoustics), however 4 speakers is the simplest solution, due to the source material.

Actually, in tests done about 30 years ago, the best large room surround was five speakers, BUT with the center in back, noth in front. The reason for the front center was twofold, first was the source material was 2-channel (rear channels in Pro-logic were mono, so why have three mono rears"), second was a center was needed up front due to the poor quality of mainstream audio gear at the time (namely speakers).

Sad part is today, the quality of speakers has went DOWN...so a center is even more cruicial in a home theater.

Now this leads to the other reason why a center is used in a PC...movies and games with lots of dialog. Reason is PC speakers in general are not very good fidelity, so having a dedicated center in the lower-end systems really does help with voices and such.


For nearfield use though, you get no real imaging benefit from anyhting more than 4 channels...and it's the imaging benefits that lead to home theaters having 7 and even 8 channels (given some are matrixed). 5.1's best benefit is a dedicated center, to make dialog clearer, that's it.

It's not always about distortion, or SPL, imaging is another big part of the picture when talking about sound, and is often the most overlooked.