Why do we need 7.1 or even 5.1

[Mightyrajh]

Hi,

I have been an audio aficianodo since the late 60's. I was around for Quadrophonic in vinyl and broadcast (WWWW in Detroit). I have set up my home with reasonable equipment but I have yet to see the use of all those speakers and amps.

Don't get me wrong,I'm not some old fuddy duddy. I don't think that Heritage and tubes sound any better than the true horn sound and analogue warmth of steel needles on shellac. But this B.S. of a centre channel and two subwoofers is driving me nuts.

Stereo was invented to give a 3 dimensional representation of a performance. The left and right channels combined in the centre to give a three dimensional effect with the mixing engineer setting the positions of the players. The lead vocal was mixed mono and appeared in the centre. Why do I need a centre channel to reproduce the same thing that stereo was invented to solve?

Subwoofers are another problem. The entire idea of a subwoofer was that the lower octaves were non directional. By building a single box that only reproduced the lower octaves then the rest of the system needed only to reproduce the upper octaves where all the seperation was perceived. Now I see specifications (7.2) calling for yet another subwoofer. Apparently non-direction frequencies still need a point source.The only reason for the subwoofer channel is to give those ersatz explosions and phoney gunshots. Real music sources very seldom get down near 20 Hz. For those members running Heritage speakers with "Heritage" equipment. The first thing that a recording engineer did before sending a master for pressing was chop off anything below 70 Hz. Digital fixed that but the only real activity below 35 Hz is just Hollywood nonsense.

My real point is that the 5.1 + specification is silly unless applied to truely subgrade equipment. Real speakers can give the whole effect with only 4.

Are there any real sound engineers out there that can explain why we need 6 speakers to do the job of 4?

[JJkizak]

One of your answers on the powered center speaker is the fact it is hugely louder and you don't have to sit within 1/4" of the center to hear the center. You can be standing next to the left or right speaker and still hear the center. I'm waiting for the 1000.50 stuff.

JJK

[dtel]

I'm waiting for the 1000.50 stuff.

Ok so no walls just speakers to shape the room, your going to need seat belts to keep you in the chair ! []

[dtel]

Don't get me wrong,I'm not some old fuddy duddy.

All of us fuddy duddys say that. [:$]

I think it's a little different now since they can have 5 separate channels for the info. Even PWK used a center channel to help fill in many years ago.

Myself I think 5 channels if done right can be all you need and the .1 sub does help fill in the last little bit for music and especially for movies it's needed.

I do know what your talking about, with a good recording even 2 CH can sound like sounds are on the sides and even the rear on occasion.

But just like a good 2 CH recording does for filling where there is not a speaker, a good 5.1 channel does it also, where it has sounds coming from there is no speakers.

But I would never do without 2 CH.

Welcome

[4tay]

Luddite!!! Luddite!!!

I remember some inert gas-pressurized (no kidding) cerwin vegas in quadrophonic. It was a neat effect.

Technology does march on. I do not subscribe to mediocre surround or mediocre subs instead of a good 2 channel.

That being said...

There are some amazing multichannel recordings like the eagles, and a lot of classical like Holst---which does present 1st octave content in the music. The effect is like quadraphonic, kicked up a notch. Just listen to the harmonies of "Seven bridges road" in 5.1. Breathtaking, to say the least.

I also don't skimp on subs. My idea of a sub is something that fills in between 20hz and 40hz cleanly, and blends with a system to reinforce, not overwhelm it. I don't want my sub to add a lump between 40 and 80hz like so many ht boom boxes do. For the music that does have content, the sub is there...but it's not welded "on". I can shut the sub off if I want to.

I also believe in a separate, dedicated 2-channel system. A system devoid of bells and whistles like EQ's, compression, synthethsized bass or special phase/delay effects. I believe that a good 5.1 system can coexist in my house with a good 2 channel system.

And don't forget.... another good old school hi-fi was a good set of Cans. Like now...Denon AH-D7000's. Isolated two channel bliss... with a nice headphone amp.

[JL Sargent]

Listening to music, sitting in the target zone, and 2CH is an amazing solution for that and all you need IMHO.

Watching a movie with 1/2 doz. friends with 5.1 or 7.1 is another mission all together. IE: If Hollywood recorded some distant directional 25hz jungle drums on the soundtract of Avatar then I want to not only hear em, but distant and directional too!

[Fish]

It's very simple, you don't need it.Some may like it, and choose it for movies,music, or hi-rez audio, that's fine too.This is a choice, to each their own for what they like.

[Bill H.]

Good Question. I use 3.1 /with a Sub.................Works for Me............[H]

[winchester21]

have you ever heard 7 Heritage speakers and a RSW 15 sub cranked th the max in a shootout during an action movie????????

Heritage HT is the s--t. The more speakers the better

bring on 9.1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I want broken windows and cracked plaster and damaged eardrums.

[4tay]

bring on 9.1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I want a Buckminster Fuller "Bucky ball" sphere of speakers... dodecahedron.1!!!

I am watching "The pacific" on HBO. There is *NO POSSIBLE WAY* 2 channel can convey the action like surround. Explosions BEHIND me...bullets whizzing by. And the low bass energy on this show is just rafter-rattling.

[IndyKlipschFan]

ed

[Islander]

Stereo was invented to give a 3 dimensional representation of a performance. The left and right channels combined in the centre to give a three dimensional effect with the mixing engineer setting the positions of the players. The lead vocal was mixed mono and appeared in the centre. Why do I need a centre channel to reproduce the same thing that stereo was invented to solve?

Subwoofers are another problem. The entire idea of a subwoofer was that the lower octaves were non directional. By building a single box that only reproduced the lower octaves then the rest of the system needed only to reproduce the upper octaves where all the seperation was perceived. Now I see specifications (7.2) calling for yet another subwoofer. Apparently non-direction frequencies still need a point source.The only reason for the subwoofer channel is to give those ersatz explosions and phoney gunshots. Real music sources very seldom get down near 20 Hz. For those members running Heritage speakers with "Heritage" equipment. The first thing that a recording engineer did before sending a master for pressing was chop off anything below 70 Hz. Digital fixed that but the only real activity below 35 Hz is just Hollywood nonsense.

My real point is that the 5.1 + specification is silly unless applied to truely subgrade equipment. Real speakers can give the whole effect with only 4.

Let's start at the beginning. Mono is non-dimensional and stereo is one-dimensional, not 3-dimensional. When listening in mono, the sound is coming from a single point. A point has no dimensions. No height, no width and no depth. Of course a real-world, non-theoretical speaker has some height and width, but in effect, the sound comes from a single point. You could say that volume is a dimension, in that it gives you an idea of the relative distances of the various instruments and voices, but that ignores the fact that some instruments are mixed louder than others, so the volume is not a completely accurate way of knowing their relative distances.

When listening in 2-channel stereo, you have two point sources and the stage is presented along the line between them. A line has only one dimension, length. It has no height or width, but for listening purposes, its length is the width of the soundstage. Accordingly, 2-channel stereo has one dimension, width, and an implied second dimension, depth, due to variations in volume.

Surround sound is 2-dimensional. It projects a sound field that has width and depth corresponding to the distance between the front speakers and the distance from the front speakers to the rear speakers. This is a flat plane, ideally at ear level, with width and depth, but no height, unless you have "presence" speakers above the front main speakers, which will add some height cues.

Moving on, as another member pointed out, the centre channel helps to anchor the soundstage, so that persons who are not sitting equidistant from both front speakers will still get some acceptable stereo effect.

Subwoofers. They're needed because almost all speakers, other than some very expensive ones, don't have flat frequency response in the lowest musical octaves. For stereo listening, two subs are ideal, but adding even one expensive bulky box to a listening room was a hard sell when subs first became popular, so we were told that one sub was all we needed. Bass being non-directional is something that's often said, but is still not accurate. The sources of lower-frequency tones are harder to pinpoint the lower you go, but are not truly non-directional in the range of music. However, since bass instruments also put out higher tones while playing low tones, a single sub located between the main speakers will give sufficiently accurate location information. On the other hand, a sub behind the listener may be fine for explosions, but not for realistic reproduction of music.

Your remark about recording engineers chopping off everything below 70Hz is something I've never heard before. If that were true, why would vintage pre-amps have a rumble filter? Even old LPs can carry fairly low-frequency information. That information could be bass guitars, which can go to 40Hz with a 4-string model and 30Hz with a 5-string instrument, while synthesizers and pipe organs can go as low as 16Hz.

There are various configurations of surround sound that have been tried over the years: 4 speakers in the corners, 4 speakers in a diamond configuration, 5 speakers in a 3+2 arrangement, 6 in 3+3, 7 in a 3+2+2 layout. The number needed for ideal projection of the surround sound field will vary according to the room and the listening position. Rear surround speakers, as in a 6.1 or 7.1 system, are not needed if the listener is sitting at the back wall, but if he or she is some distance from the wall, one or two rear speakers will give extra depth and realism to the soundfield.

Another factor is how the sound was recorded and mixed. For the early Quadrophonic system records, 4 speakers were used, but for modern Dolby, DTS and newer formats, 5.1, 6.1 or 7.1 is how the music or movie was recorded and is how the speakers should be arranged for proper playback.

I hope this clears things up a bit.

[Mightyrajh]

Islander

The rumble filter was for turntable rumble. It would filter out noise from the drive wheel and also take care of record warp. It was pretty common to see a demo setup with a direct coupled amp driving the woofer from stop to stop at about .5hz (33.3 rpm) even in the quiet passages..

[russ69]

Call me stuck in the mud but 2 good channels are better than 7 lessor ones. Now if you already have 4 Jubilees up front in a stereo configuration and you are looking for more, knock yourself out get the another 7 channels and the amps to go with them but you are out of my price range by then. I'll stick with two good channels.

[Frzninvt]

While my NAD A/V pre-pro has the ability to playback in 2 channel I find it dull and lifeless after listening in my typical 7.2 configuration. My mains image so well in 2 channel that you would swear the center speaker is playing.

I just prefer the full enveloping sound of all channels playing simulataneously. Makes me feel like I am at a concert in the middle of thousands of cheering fans if it's a live recording.

Without a capable subwoofer you are missing out on one or maybe two octaves of music, play the Titanic soundtrack on your subless 2-channel setup then go hear it on one with a capable subwoofer - there is no comparison. Even the mighty Klipschorn needs a subwoofer to fill in the void.

My NAD AV pre-pro upsamples all signals to the 7.2 configurations so all speaker are always utilized. Two dedicated subwoofer outputs as well.

There is plenty of content in the 7.1 array, all the remixed Star Wars and all the most current movie releases make full use of the additional surround channels.

To each his own if you want to stay stuck in the 70's that is your choice. I did not make the jump to multi-channel until 2000 I held onto my 2-channel until I was convinced otherwise from a friend of mine that had an audio store played me a multi channel demo of the Eagles "Hell Freezes Over" concert that made the hair on my arms stand up from the realism and accuracy I was seeing and hearing.

[Islander]

Islander

The rumble filter was for turntable rumble. It would filter out noise from the drive wheel and also take care of record warp. It was pretty common to see a demo setup with a direct coupled amp driving the woofer from stop to stop at about .5hz (33.3 rpm) even in the quiet passages..

You got me there, but even so I believe that LPs do have low-frequency content down to at least 30Hz. I looked around on the Net, but didn't see any references to LP bottom end, but I did find this interesting clip in which this guy compares CD and LP high end response. You can see clearly that CDs contain nothing above 20KHz, while LPs may have content to 60KHz and beyond.

Audio frequency of LP vs. CD:

As for multi-channel versus 2-channel stereo, I usually listen to each as it was recorded, multi in multi or 2-channel in 2-channel.

[russ69]

To each his own if you want to stay stuck in the 70's that is your choice.

Stuck in the 70s? You are giving me too much credit. I grew up on my Dad's 1950's hi-fi rig!

[twistedcrankcammer]

have you ever heard 7 Heritage speakers and a RSW 15 sub cranked th the max in a shootout during an action movie????????

Heritage HT is the s--t. The more speakers the better

bring on 9.1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I want broken windows and cracked plaster and damaged eardrums.

winchester 21,

It has already existed for some time. I have already experienced 12 channel with 6 subs for home use.

Roger

[Tom Adams]

Sheesh......what an easy question to answer. We need it 'cause "They" told us we do and that without it you would NEVER truly experience the movie the way the recording engineers meant for you to hear it.

Is that last sentence true? I dunno. Maybe. I can tell you from personal experience that the non-audio enthusiast does believe they need it to watch movies at home. That all movie DVD's or streamed content contains some magical sound that without the aid of multiple speakers, you'll not enjoy the movie near as much.

Me? Well.....back some 7 or 8 years ago when I had the world by the tail (or so I thought), all I could think about while planning to build the house of my dreams was the dedicated home theater room that would be 7.1 and not some easy to achieve 5.1 room. And it came to pass. I must admit that it was a fun and exciting thing. Buying equipment, refinishing speakers, designing & room layout, running wires, decorating, learning about projectors, etc. But what I found was that it was never finished. I found myself constantly tweaking the system. One movie's surround content would be fine and another's not. Then there was the acoustic issues to tame. Center channel dialogue was all over the map. Honestly, after living with that HT for almost 2 years, I can't say that I was ever really satisfied.

Today, due to extinuating circumstances, I watch movies on a 65" Samsung LED RPTV fed by a Sony BD player with sounds by a pair of Klipsch Cornwalls and a SUB-12 via a Denon reciever. The biggest difference? Now I watch movies. In the 7.1 HT room I was interupted by myself and my nagging questions about sound and acoustics. It's kinda nice watching a movie and not interupting myself.

Would I ever do a multi-channel HT room again? Probably - if money was no object. But right now I enjoy the performance and am not so enamoured with all the lights and multiple piece of electronics. I do enjoy a big screen that projectors provide so maybe my future system is a 2.1 front projector.

Tom

[twistedcrankcammer]

Call me stuck in the mud but 2 good channels are better than 7 lessor ones. Now if you already have 4 Jubilees up front in a stereo configuration and you are looking for more, knock yourself out get the another 7 channels and the amps to go with them but you are out of my price range by then. I'll stick with two good channels.

Russ,

That is exactly why I now have 7 TSCM speakers. I also have 5 MWM doubles, and should have 4 MWM singles within a week or two. This will give me the equivelant of 7 MWM doubles, which I may have to start collecting 402 horns to put on top of. []

I can always set pre amp on stereo, and not too many here have two channel systems that could compete.

Roger