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Why exactly are surrounds effect speakers?

post #1 of 19
3/31/12 at 1:04pm
Thread Starter 
So I'm planning out a new speaker system that will be primarily playing games. Because of this having surrounds that give me positional audio seem like a good idea. This got me thinking though that when movies are played the positional audio may be a bad thing as the position of surrounds aren't meant to be determined. Which in turn made me question why that is.

Why are surround speakers (at least for movies) effect speakers and not positional speakers?

The only thing that's ever said about it is that that's how the mixers design the audio track. That, however, is not a reason and certainly there are times when a scene could benefit from positional surround audio.

Let's say there is a good reason for why surrounds are effect speakers. Then why do we need 2+ speakers? Why not just 1 speaker ceiling mounted in the middle that fires in all directions (omnipole?) Wouldn't this give us the same effect as 2+ surrounds?
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post #2 of 19
3/31/12 at 1:08pm
Surrounds that are properly installed "image" much like stereo speakers. When the mix allows they offer precise sound placement. This is the main reason I'm not a fan of bipole/dipole surrounds.
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post #3 of 19
3/31/12 at 1:30pm
I'd rather have two pair of bookshelf speakers for surrounds than bipole,dipole or quadpole. I demoed the Axiom QS4/8 and I perfer the Axiom M2 or M22s compared to the QS models, much more precise and accurate sounding. Instead of just throwing sound everywhere.
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post #4 of 19
3/31/12 at 2:05pm
I prefer monopoles to dipoles with the caveat that I think the mains and surrounds need to be identical for optimal effect. I have not had bipoles in my system but have heard a lot of folks say they are as good as monopoles but diffuse as well. Don't know though. If there is any priority for multichannel music I think that monopoles are the way to go.

Having said all of that, there are specific room constraints and issues that may make a specific design superior to another. So careful consideration there will give best results.
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post #5 of 19
3/31/12 at 2:28pm
Quote:
Originally Posted by Gooddoc View Post

If there is any priority for multichannel music I think that monopoles are the way to go.

My main priority is movies but have a large collection of DVD A and DTS cds and quad, di and bipoles don't sound as nice as matching stereo and surrounds.
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post #6 of 19
3/31/12 at 8:35pm
Thread Starter 
Yeah, I think I prefer monopole over bi/dipole and for it to match the fronts. I haven't heard enough speakers to really make that decision, but I'd rather know where the sound is coming from and for it to not sound different than to be "envoloped" with sound that may or may not match the fronts. Thanks for reassuring me on my potential path.

I would still like to know why the surrounds are meant to be effect speakers? Only thing I can think of is so that you don't need a set of of speakers at each row to give a side surround effect. Again, though, why not have one omnipole speaker ceiling mounted to give the "surround effect?" With it positioned properly wouldn't you be able to have the sound reflect off the side and rear walls giving much the same effect as 4 bi/dipole speakers?
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post #7 of 19
3/31/12 at 10:06pm
um... one rear ceiling mounted effects channel... like a 4.1 system? could that give any real left and right directionality to any sound that's supposed to come from behind? Or are you talking about a 6.1 system, with rear left and right, and one centered 'rear effects' channel? Because that's entirely do-able. I scored a great deal on a 6.1 system from shoponkyo a couple years back, right when they ditched that for 7.1, but that's OT. More important is that the 'rear center' had very little impact. So you could probably utilize a speaker that's already there as a 'rear center' in a 6.1 setup... but there's really no need. A well set-up 5.1 will sound better than a 6.1 with one mismatched speaker. And if you want to go full surround 7.1, you wont use it at all. Nor would you use it for a 9.1 using 'front wides' or 'front highs' or even 11.1 using both. The rear center channel, which is the only thing you could use a centered speaker behind the listening position for .. has been tried, and failed. 6.1 didn't last long, for a reason. 4.1 ? no thanks. The mere fact you're on this forum, and the ? you've asked, indicate to me you care about the sound you hear.
Isn't one aspect of a good system NOT being able to hear where the sound is coming from (localize each speaker)? Versus being just enveloped by the sound?
I'm not a gamer, but my boys are (3 teenagers), and I know it's important for gaming to hear if someone's creeping up behind you to the left or right... So they are 'positional', not just 'effects'... and for gaming, the difference between 5.1 and just a stereo left and right, is huge compared to the difference between that and 7.1 or 6.1, especially if #6 doesnt match... hope this makes some sense and helps someone.
Joe
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post #8 of 19
3/31/12 at 11:15pm
hate to double post... but I re- reread your original question a 5th time. What makes you think rear speakers are just for 'effects'? Those effects ARE to give Directionality to the sounds that are supposed to (appear to ) come from behind. Rear channels are what... 20% of the total soundtrack ? for movies at least? but that 20% IS what gives a sense of direction from sounds from behind? Like the human ear is much more directionally sensitive to sounds that come from in front? We just aren't made to hear direct sounds from behind. But we can, to some degree.. just nowhere near as well as we can locate sounds from in front. Movie makers and game designers know this also. For music... 2 channel (2.1 or 2.lots is better) is really all you need... but that's not what you indicated. For gaming and movies.. the rears are 100% directional... at least in the intent of the movie/game producer.
This is all my opinion only, so no more negative PM's are necessary (you know who you are) . I have no experience re: dipole, tripole, etc... and I havn't even brought that up)
I'm only trying to pay it forward.
Joe
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post #9 of 19
3/31/12 at 11:16pm
Quote:
Originally Posted by gtpsuper24 View Post

I'd rather have two pair of bookshelf speakers for surrounds than bipole,dipole or quadpole. I demoed the Axiom QS4/8 and I perfer the Axiom M2 or M22s compared to the QS models, much more precise and accurate sounding. Instead of just throwing sound everywhere.

The "throwing sound everywhere" is exactly the way I want my surrounds to perform in my room. I understand what you, and others prefer, but many of us don't have the ideal room. We have our systems set up in a small to medium room with perhaps the main seating on the rear wall instead of out in the middle of the room. Therefore mounting dipole or bipole surround speakers up high and "throwing sound everywhere" vs. using directional speakers provides a more convincible effect for movies and DVD concerts. A live concert disc has lots of audience and ambient noises encoded in the surround channels. Using a directional surround sound speaker in my room just wouldn't work for me. Not knowing where the surround effects are coming from sounds right to me.
On the other hand, I have listened to a 5.1 system where the sofa was positioned out in the middle of a large room, and the rear surrounds were mounted on stands at ear level and placed maybe ten feet behind and over the shoulder, and the sound was amazing, specifically music on a good SACD. So, I'm not trying to create an argument...I'm just saying what honestly works the best in my room.
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post #10 of 19
4/1/12 at 1:34am
Quote:
Originally Posted by Narfster View Post

Yeah, I think I prefer monopole over bi/dipole and for it to match the fronts. I haven't heard enough speakers to really make that decision, but I'd rather know where the sound is coming from and for it to not sound different than to be "envoloped" with sound that may or may not match the fronts. Thanks for reassuring me on my potential path.

I would still like to know why the surrounds are meant to be effect speakers? Only thing I can think of is so that you don't need a set of of speakers at each row to give a side surround effect. Again, though, why not have one omnipole speaker ceiling mounted to give the "surround effect?" With it positioned properly wouldn't you be able to have the sound reflect off the side and rear walls giving much the same effect as 4 bi/dipole speakers?

Your post makes me think that you haven't heard, or observed a good surround effect in a good movie. A good example is the scene in Saving Private Ryan when numerous boats beach themselves, the doors open and the soldiers start wading through the water trying to make it to shore. There is a barrage of enemy bullets being fired all over the place, hitting the metal barricade's. One surround speaker just wouldn't do the job.
Another example would be a scene where a motorcycle is coming right at you, then runs off of the bottom right side of the screen. The panning effect results in the sound moving from the front speakers, and then finishing of in the right surround speaker, as the volume starts to drop making it sound like the bike is moving on down the road.
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post #11 of 19
4/1/12 at 7:43am
Quote:
Originally Posted by Espo77 View Post

Your post makes me think that you haven't heard, or observed a good surround effect in a good movie. A good example is the scene in Saving Private Ryan when numerous boats beach themselves, the doors open and the soldiers start wading through the water trying to make it to shore. There is a barrage of enemy bullets being fired all over the place, hitting the metal barricade's. One surround speaker just wouldn't do the job.
Another example would be a scene where a motorcycle is coming right at you, then runs off of the bottom right side of the screen. The panning effect results in the sound moving from the front speakers, and then finishing of in the right surround speaker, as the volume starts to drop making it sound like the bike is moving on down the road.

+1. Don't think a single surround speaker would work nearly as well as two.
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post #12 of 19
4/1/12 at 11:07am
It's a mixed bag. The traditional notion of multichannel stereo film mixing is that you're never supposed to draw people's attention away from the screen. Tom Holman, the creator of THX, was a big influence on movie sound since the 1980s or so and he was also largely responsible for the advent of dipoles for surrounds and for pushing the concept of the "sound field".

When the original roadshow edition of "Close Encounters of the Third Kind" was released in 1977, the 70mm Dolby format still had mono surround. But they could effect localization effects by combining the mono surround with one of the front channels (and they could also delay signals to enforce localization). When the sound from the alien ship blows the glass in the viewing tower, the audio appeared to come from the right surround. The sound was so realistic (at the Ziegfeld, in NYC) that everyone in the audience turned their heads to the right. That was considered a big "no-no" and that scene was remixed for later editions of the film.

On the other hand, "split-surround" was developed for "Apocalypse Now" precisely because more accurate fly-overs of helicopters was desired by Coppola and Walter Murch, the sound designer. This was followed around 1990 by the standard digital sound format, 5.1, which gave us the standard stereo surround and then by Dolby EX and DTS ES, which gave us a derived center rear, although when I went to theatres that added the EX or ES, I could never perceive the difference.

In addition, mixers always had to be cognizant of the fact that the film had to work in theatres that didn't have surround, so that you never had anything "mandatory" in the surround channels. Also, because surround speakers need to hang on the walls of theatres, they never have the full-range frequency response that the fronts have. So their role has always been one more of diffuse effects.

Obviously, both theatrical and Blu-ray home formats can now give us four surround channels (7.1 or more) so much more obvious localization can be achieved, but most sound mixers still use those channels mostly to create an enveloping sound field and not for a lot of discrete effects.

In the music world, mixers have taken both approaches. Some mixers put you in the position of an audience member and only send reflections to the rear speakers. Others put you in the middle of the band and send specific instruments to the rears.

Dolby is announcing something new at CinemaCon on April 23rd. I have no idea what it is, but they're pushing it in the trades and on their website. I have a feeling they'll be announcing 10.x or more channels for theatres. The question is whether those new channels will be heights, wides or both. And of course, they'll be issues as to whether the studios will discretely mix for it or whether they'll use the same cruddy (IMO) channel derivation tools that are used in the home to expand to wides and heights. And once again, they'll be a chicken and egg situation where the studios won't provide films in that format until the theatres convert and the theatres won't convert until films are provided in that format. And after just going through upgrades to digital and other upgrades to 3D, most theatre chains are not ready to invest in a sound overhaul. But who knows- maybe Dolby is going to announce something I haven't guessed at.
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post #13 of 19
4/1/12 at 2:21pm
Quote:
Originally Posted by Jay1 View Post

Surrounds that are properly installed "image" much like stereo speakers. When the mix allows they offer precise sound placement. This is the main reason I'm not a fan of bipole/dipole surrounds.

What type of surround spkr are you referring to that images like a stereo pair.
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post #14 of 19
4/1/12 at 2:33pm
I don't think he is referring to a speaker, some mixes have the surrounds image just like stereo speakers do.
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post #15 of 19
4/1/12 at 3:21pm
Thread Starter 
Quote:
Originally Posted by wlhungdude View Post

um... one rear ceiling mounted effects channel... like a 4.1 system?

Kind of. Hopefully I can explain my ceiling mounted speaker idea more clearly here. What I meant by the ceiling speaker was a speaker mounted above the primary, middle listening positon that fires sound at an angle towards the left, right, and rear walls that would then reflect off those surfaces towards the listening position.

Quote:
Originally Posted by wlhungdude View Post

hate to double post... but I re- reread your original question a 5th time. What makes you think rear speakers are just for 'effects'? Those effects ARE to give Directionality to the sounds that are supposed to (appear to ) come from behind... For gaming and movies.. the rears are 100% directional... at least in the intent of the movie/game producer.

From speaker setup guides I've read in the past and...

Quote:
Originally Posted by wlhungdude View Post

Isn't one aspect of a good system NOT being able to hear where the sound is coming from (localize each speaker)? Versus being just enveloped by the sound?
I'm not a gamer, but my boys are (3 teenagers), and I know it's important for gaming to hear if someone's creeping up behind you to the left or right... So they are 'positional', not just 'effects'...

See where I'm getting confused? Sometimes I'm not supposed to know where the surround sound is originating from and other times I am? Looking into this a little more I found an Audioholics guide and I think I'm beginning to understand the role of the surrounds a bit better. I believe what it says is that I don't want any one speaker overpowering anyother, making it difficult to pinpoint exactly what sound is coming from which speaker. On the other hand, the speaker should also be able to be located through sound if the track was mixed in such a way to allow it. Am I understanding this correctly?

Quote:
Originally Posted by Espo77 View Post

The "throwing sound everywhere" is exactly the way I want my surrounds to perform in my room. I understand what you, and others prefer, but many of us don't have the ideal room. We have our systems set up in a small to medium room with perhaps the main seating on the rear wall instead of out in the middle of the room. Therefore mounting dipole or bipole surround speakers up high and "throwing sound everywhere" vs. using directional speakers provides a more convincible effect for movies and DVD concerts. A live concert disc has lots of audience and ambient noises encoded in the surround channels. Using a directional surround sound speaker in my room just wouldn't work for me. Not knowing where the surround effects are coming from sounds right to me.
On the other hand, I have listened to a 5.1 system where the sofa was positioned out in the middle of a large room, and the rear surrounds were mounted on stands at ear level and placed maybe ten feet behind and over the shoulder, and the sound was amazing, specifically music on a good SACD. So, I'm not trying to create an argument...I'm just saying what honestly works the best in my room.

As I thought, room and seating arrangement (as well as personal taste) have an effect on whether one goes for monopole, bipole, or dipole.

Quote:
Originally Posted by Espo77 View Post

Your post makes me think that you haven't heard, or observed a good surround effect in a good movie.

You're probably right. I have basically no experience with different speaker systems and have never even auditioned any because I have no idea of what I want to hear, nor do I understand the lingo that thrown about. I installed a BIC Acoustech system in my parents house some years ago as my first speaker system. It's nice enough, but the surrounds seemed a bit muddled. They are PL-66's I believe and they look like a horizontal TMM layout. I don't know what kind of pole that makes them. Of course it could also be that I think I placed the rears to close to the sides so there isn't enough seperation.

The next system I installed was for my cousin last summer where I used a Jamo S606 5.0 system. The surrounds in this package are monopole speakers and they just seemed more crisp and detailed. Now whether this is because her room had a better layout (parents setup is angled instead of perpendicular to the wall,) I placed the speakers better, or I just like the Jamo's over the BIC's, I couldn't say. The odd thing is that even after she moved the couch back to the end of the room and the sides ended up being in front, I thought it still sounded good. Of course it sounded even better in her recliner which is still slightly in front of the sides. Now I haven't listened to much on her system so I could very well find something I don't like about it, but initial impressions were good, especially at the price it was. With this I'm inclined to go with monopoles for the surround.

Quote:
Originally Posted by zoetmb View Post

It's a mixed bag. The traditional notion of multichannel stereo film mixing is that you're never supposed to draw people's attention away from the screen. Tom Holman, the creator of THX, was a big influence on movie sound since the 1980s or so and he was also largely responsible for the advent of dipoles for surrounds and for pushing the concept of the "sound field".

When the original roadshow edition of "Close Encounters of the Third Kind" was released in 1977, the 70mm Dolby format still had mono surround. But they could effect localization effects by combining the mono surround with one of the front channels (and they could also delay signals to enforce localization). When the sound from the alien ship blows the glass in the viewing tower, the audio appeared to come from the right surround. The sound was so realistic (at the Ziegfeld, in NYC) that everyone in the audience turned their heads to the right. That was considered a big "no-no" and that scene was remixed for later editions of the film.

Thank you very much, zoetmb. That is the kind of answer I was looking for in regards to my title question. With my years of gaming I won't have that problem of moving my head as instead I'll just move my character so that the sound comes from the front speakers. Of course this then leaves a bit of a dilemma with movies and other people. I don't think I'd move my head, but I don't know about others when watching a movie. Also, even though one isn't meant to be able to pinpoint where surround sound is coming from one should still be able to have an idea of where the surround is coming from. With this and the fact that in games when I turn around, thus causing the surround sound to play out of the fronts, makes me wonder if going bi/dipole wouldn't be so bad after all. I guess it comes down to what friends and family would prefer. I believe I like direct firing monopole surrounds, but comprimising with bi/dipoles to give everyone a better experience wouldn't be such a big deal...

Just thought of something here, are there tripole speakers? If so would that give me the best of both worlds, i.e. the wider soundstage of bi/dipole speakers with the localized sound benefits of monopole?

Thanks everyone for the insight into surround theory.
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post #16 of 19
4/2/12 at 8:00pm
Quote:
Originally Posted by Narfster View Post

Thank you very much, zoetmb. That is the kind of answer I was looking for in regards to my title question. With my years of gaming I won't have that problem of moving my head as instead I'll just move my character so that the sound comes from the front speakers. Of course this then leaves a bit of a dilemma with movies and other people. I don't think I'd move my head, but I don't know about others when watching a movie. Also, even though one isn't meant to be able to pinpoint where surround sound is coming from one should still be able to have an idea of where the surround is coming from. With this and the fact that in games when I turn around, thus causing the surround sound to play out of the fronts, makes me wonder if going bi/dipole wouldn't be so bad after all. I guess it comes down to what friends and family would prefer. I believe I like direct firing monopole surrounds, but comprimising with bi/dipoles to give everyone a better experience wouldn't be such a big deal...

Just thought of something here, are there tripole speakers? If so would that give me the best of both worlds, i.e. the wider soundstage of bi/dipole speakers with the localized sound benefits of monopole?

Thanks everyone for the insight into surround theory.

I think you're over-thinking this. If you prefer to hear localization because you do a lot of gaming, etc., then you probably don't want dipoles. But the best thing to do is to go to a good audio store and LISTEN. Have them switch between dipole based surrounds and regular surrounds and see which you like better.
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post #17 of 19
4/2/12 at 8:33pm
Quote:
Originally Posted by zoetmb View Post

I think you're over-thinking this. If you prefer to hear localization because you do a lot of gaming, etc., then you probably don't want dipoles. But the best thing to do is to go to a good audio store and LISTEN. Have them switch between dipole based surrounds and regular surrounds and see which you like better.

Or, better yet, there are several speaker manufacturers that make surrounds that allow you to switch between monopole, bipole, or dipole...$$$..$$$.
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post #18 of 19
4/2/12 at 9:59pm
Quote:
Originally Posted by Narfster View Post

See where I'm getting confused? Sometimes I'm not supposed to know where the surround sound is originating from and other times I am?

I don't know how the sound in games works, on-the-fly, but for movie soundtracks the surround channels can be used to provide everything from diffuse ambiance to punctate directional cues. It all depends upon the engineer's intent and how the particular effects are mixed for the soundtrack. If it is the intent, though, diffuse ambiance can easily be mixed into the soundtrack at production. And, yes, a pair of direct radiating monopoles can reproduce that diffuse ambiance quite well. But true dipoles cannot reproduce what is supposed to be a punctate directional effect as well as direct radiating monopoles can.
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post #19 of 19
4/4/12 at 10:24am
What about a speaker like the Klipsch RS-41? With the listener facing mid-range, and dipole tweeters? Would that give a decent sound localization for gaming while still creating a wide "effects field"?
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