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Why 7.1 Surround Sound is Overkill For Most Homes
RX8 writes "Home Theater expert Mark Fleischmann explains why you should not fall for the 7.1 hype and why 5.1 surround sound is adequate for most homes. From the article: 'With the marketing of 6.1 and 7.1 surround, the industry has decisively outwitted itself. It has convinced many consumers to buy new receivers and more speakers. But it has also undermined the 5.1-channel standard, which is more appropriate for the home, slowing the acceptance of surround sound in general.'"
Unless you're a real videophile, you're probably better off just buying two really nice speakers instead of 7 average ones. Not to mention the rats nest of cables 7 will result in.
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Indeed. I for one would prefer to have two decent speakers driven by amps with a frequency range of 4Hz-20kHz +/-1dB at 1%THD, than to have any number of crappy speakers driven by amps with a frequency response of 100Hz-10kHz +/-6dB at 10%THD.
Informal experiments with my neighbours would seem to suggest that when listening to music outdoors, THD is more noticeable than absolute volume: you can play it as loud as you like as long as it's coming through crystal clear, but the minute you introduce a little distortion you will be asked to turn it down.
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Get a light source and a large piece of posterboard. Cut two vertical slits fairly near each other in the posterboard so that a little bit of light can be projected through the slits onto a wall. Now shine the light through the slits. Holy cow! It creates a rippled pattern on the wall!
This is because the light is actually a wave that is propagating towards the wall. When it passes through each slit, the light forms two wave fronts which interfere with each other. This causes some areas of the target (the wall) to receive light photons while other areas receive none. Where there are no photons, the waves have simply cancelled each other out. It's a pretty cool experiment and quite counter-intuitive.
What if you do the same with speakers? Well, sound is a wave. And it's also known that soundwaves will interfere with each other (sometimes called 'beat'). So once you start adding more speakers to a system, you get more interference and less audio quality. Just like the double slit experiment, the results are counter-intuitive!
There's so many ways to make mistakes when setting up sound - and with more stuff, more choices, more tweaking possible, all but the most dedicated sound geeks are simply getting more ways to mess it all up.
The reality is that for most people, setting up two good speakers, or maybe two speakers and a subwoofer in the center, is going to give them the best sound. Add various little satellite speakers and stuff that is really dependent on the room layout, the prescence of sound reflecting and absorbing materials (table surfaces, soft couches etc.), the unpredictability of where people are sitting and chances are they will end up with a soundscape that sounds decidedly worse than they had with a simple 2 speaker or 2+1 speaker setup.
It's like having high-end Öhlins shock absorbers on your bike. For the riders that _are_ (not just think they are) knowledgeable, interested, and ready to spend a week tinkering, they will give superior performance to the factory default shocks. For the rest of us, they're just an expensive invitation to utterly screw up the bike handling beyond all help.
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Replace often with always. I can understand how some audiophile might appreciate the ability to fine tune dozens or hundreds of parameters such as speaker positions, direction, tilt, balance, cabling etc. With such people the quest for perfection is neverending and sometimes exceeds common sense. I suspect that most other people would be happy with a sub $6000 5:1 system from their local electrical outlet or nothing at all.
I myself like watching films on my big widescreen TV but I haven't had a strong urge to hook it up to a sound system. The speakers do the job adequately for my needs. Just the thought of extra cabling, power plugs, amps (occupying space in my cabinet) and remotes puts me off. The same goes for my PC. I play lots of FPS games, but I make do with a pair of stereo speakers and a subwoofer, both of which were bundled with my last PC. It would be nice to hear sounds from behind but IMHO not worth the hassle of all that extra gear.
Also, for as cool as HRTF can sound, the illusion breaks the moment you move your head. We move our heads all the time, and our brain takes this in to account with our audio perception. Ot expects the sound will change in a certian way as our head moves. We actually uncounciously use this to help us localise sounds. Well with headphones, the entire soundfield rotates with you. It's not natural, and you notice it.
That doesn't mean it's useless, however it's still not as realistic as multiple speakers.
This whole "clipping is a fact of life except in expensive systems". No, not so much actually. I'd be really supprised if most good reciever/speaker combos ever clipped. It's not hard to build an amp that has plenty of power for home theatre, espically when you are talking the distances at which the speakers will be placed. Generally people aren't going to be running them at a whole lot more than a couple watts RMS.
The thing is that recievers are all transistor amps, and clipping is really noticable on transistors. Transistors are essentally completely linear up to a point, then they just stop hard and don't put out any more power. It isn't quite as harsh as digital clipping, but close. It's not smooth like tube clipping where the tube slowly enters a non-linear zone.
Also, more channels wouldn't give a reciever any more reason to clip. Each channel is a seperate amp. What matters in regards to clipping is the amount of power going in to a single channel. If it's more than the channel can handle, you clip, if not, you don't. What's happening on the other channels isn't relivant.
He's also wrong that there's no reason to want more speakers just because there's no seperate encoding for them. If that were the case, why the hell do theatres have more than 5 speakers? Well, because the sound would suck. You have people all spread out, you need surround speakers all along the walls to get a good, diffuse surround field that's pleasant for all of them.
It's actually the same reason behind a centre channel. In theory on a good setup, such a thing sould be unnecessary. Indeed you find this is the case, if you have two quality speakers that are focused on a listener, they can generate a perfectly centred sound by playing in unison. No need for a speaker there. However, that relies on a very small sweet spot. If people are spread out, the illusion breaks. So, we just put a speaker in the dead centre, and send the sound there. It makes the sound seem to come from the middle of the screen, regardless of your angle to it.
The real reason not to get 7.1 in most cases is you are wasting money because your listening area is too small to really benefit from more speakers. However, it's not going to make your reciever clip or anything, unless you've got a seriously screwed up reciever.
I agree that anything setup badly will not make any difference and in the case of 7.1 it would be a mess. But if you have gone 7.1 then I assume they have paid good money for something to drive it and some good kit to host it. If you have paid less than 5k for your setup then it's probably pointless to go 7.1.
Just because your average Jo doesn't need 7.1 tho doesn't make it any less good. TFA misrepresents the benefit on the basis that it doesn't make much difference to a non cinema environment...This is not true.
Well with headphones, the entire soundfield rotates with you. It's not natural, and you notice it.
When playing a video game, I move my head, and the games visual field stays completely still. It's not natural and I don't notice it.
The game's sound and visual field are not a real world one. Me moving my head should have no effect on the sound I hear. If it does, I've done something wrong, like waste money on four more speakers.
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