AVS Forum banner
Status
Not open for further replies.
1 - 20 of 21 Posts

·
Registered
Joined
·
438 Posts
Discussion Starter · #1 ·
I currently have a 5.1 set-up with Wilson speakers all around (ex sub woofer). I have Watt Puppy L/Rs, and a Watch center and surrounds.


My question is about the surrounds. The Watch surrounds are not bipoles/dipoles. I think this is o.k. for rears in a 5.1 set-up. However, I'm moving to a new house and plan to set up 7.1 sound. My sense is that in a 7.1 set-up, I want true bipole/dipoles for the sides throwing sound away from the listener (with the rears o.k. as direct radiating speakers still pointed at the listener). If so, I'm not sure what to do as I don't want to go to another brand for just the sides, and don't think Wilson makes matched bipole or dipole surrounds/sides.


Any advice would be appreciated. I know there's a significant chance I'm out to lunch in my understanding of this issue.


Thanks.
 

·
Registered
Joined
·
3,947 Posts
A growing number of us feel that we now have enough separate audio channels that de-correlation (the di-poles forté) has become unnecessary. We want to know where the sounds come from.
 

·
Registered
Joined
·
438 Posts
Discussion Starter · #3 ·
Quote:
Originally posted by Larry Fine
A growing number of us feel that we now have enough separate audio channels that de-correlation (the di-poles forté) has become unnecessary. We want to know where the sounds come from.
That's a really interesting point, thanks.
 

·
Registered
Joined
·
321 Posts
Quote:
We want to know where the sounds come from.
Some of us with 7.1 systems like having a seamless 360 degree sound stage, not merely seven discrete points of sound spread around the room. Ideally, we should get a good sense of where in that 360 degree sound field a sound is coming from, but without having it localized to a specific speaker. That salutatory effect can be achieved with examples of speakers of any design (direct radiating, bipole or dipole) when properly placed and level-calibrated. The ease of achieving this "holy grail" of surround sound with the different designs, however, may differ depending on which speakers are used and the environment they are placed in. (Room characteristics can throw off or enhance the best of designs.)


Burke
 

·
Registered
Joined
·
1,109 Posts
Hi,

In my system the speakers that are matched are the fronts and the direct radiating sourrounds which are the Totem model 1's and are used for music. I use Axiom mlti firing qs4's for film and if i was concerned about a match at one time, that feeling is long gone.


I also use monitor bronze for rear effects .


Again if there are 4 speaker you feel you must match and you can have surrounds A and B, i would match the ones you use for music.


Peter m.
 

·
Registered
Joined
·
3,947 Posts
Burke, I agree that a seamless sound stage is desirable. When any two speakers are wired (or otherwise) in phase, sounds common to both seem to come from between them. When the speakers are out of phase, the effect is lost, and there is an audible 'hole'. This is why polarity is so important in stereo*.


*(Many people don't know this: stereo began with 3 channels; the main mono high-fidelity speaker that home audio began with, and a pair of satellites was added. The center was dropped later on, and relative polarity maintained the phantom center image.)


Since di-poles have one face's drivers wired out-of-phase with the other, one face of the speaker will be out of phase with the next speaker in the 'circle', either the main on that side of the room, or the rear on that side, depending on which side of the room which di-pole speaker is placed. But which one?


In other words, which direction should the out-of-phase face face? Front or rear? With all direct-firing or bi-poles, all speaker faces are in phase with one another, so the seamless between-the-speaker soundstage can be acheived more easily.


I guess that one fix could be to wire the rears out of phase, and mount the di-poles with the out-of-phase face toward the rears. That way, the only 'hole' would be from the di-poles themselves. My opinion is that this could be a benefit if the side speakers were significantly closer to the seating than the rest, otherwise no.


My speakers (with the exception of the center) are all bi-polar, which I feel maintains the seamless sound while providing the expanded sound necessary to fill the spaces between speakers. I don't hear discrete points of sound.


There are no between-speaker spaces that have out-of-phase speakers trying to provide a phantom image. The side speakers face front and rear, like di-poles, but all drivers are in phase, like direct-firing speakers. The benefits without the drawbacks.
 

·
Registered
Joined
·
42 Posts
Quote:
Originally posted by thegratingone
My question is about the surrounds. The Watch surrounds are not bipoles/dipoles. I think this is o.k. for rears in a 5.1 set-up. However, I'm moving to a new house and plan to set up 7.1 sound. My sense is that in a 7.1 set-up, I want true bipole/dipoles for the sides throwing sound away from the listener (with the rears o.k. as direct radiating speakers still pointed at the listener).
I find it's quite the contrary.

In a 5.1 some people prefer to use bi/dipoles as surrounds to get a more "diffused" sound and thus a "smoother" soundstage.

There's really no need for that in 7.1 imho.

The added side speakers give you a more enveloping surround soundstage than a 5.1 setup ever can.

I say, go with matching speakers for the sides/rear.

It is far more important imho to timbre match the speakers than to diffuse the sound from the side speakers.
 

·
Registered
Joined
·
30,355 Posts
Quote:
Many people don't know this: stereo began with 3 channels
Stereo, from the old Greek 'sterios', means "solid"; it has nothing specifically to do with the number "2" (as in 2 channels or 2 speakers). Because the popular carrier at the time was LP records, which could only carry two channels, we ended up being saddled with this limitation. When Bell Labs first demonstrated "stereo" reproduction, it was in fact a 3 channel system; and that was indeed what we were to transition to after mono. Oh well, better late than never.
Quote:
Since di-poles have one face's drivers wired out-of-phase with the other, one face of the speaker will be out of phase with the next speaker in the 'circle', either the main on that side of the room, or the rear on that side, depending on which side of the room which di-pole speaker is placed. But which one?


In other words, which direction should the out-of-phase face face? Front or rear?
All dipoles have positive and negative phase sides. Setting up 4 of them for surround purposes is not difficult at all, as long as you remember to keep similarly phased drivers pointing at each other in order to avoid cancellations. See attached diagram.


Best,

Sanjay
 

·
Registered
Joined
·
499 Posts
would you guys go w/dipoles/bipoles if the position of the side speakers were to be relatively close to your head? (about 4-5ft on each side)? I have a mini theater 11x15. Granted they could be mounted higher on the wall but I don't know how sucessful this would be. I don't even have surrounds yet, I may be able to demo both types in my room though.
 

·
Registered
Joined
·
1,646 Posts
I sit about 6 ft from my back surrounds (all are bi-poles). If you have the levels set right, don't worry about it. I'd definitely try direct radiators in addition to di/bi poles and choose the ones that work best based on how they sound. For me, 4 bi-poles worked out perfect; for you, it could be different.


Sorny
 

·
Registered
Joined
·
1,109 Posts
Kingo,

My room is, (dimension wise) almost identical to yours. Before i purchased my 7.1 reciever i used the Axiom qs4's mlti firing surround speakers at the same spacing that your describing with excellent results.


I have recently however, done an almost complete change and addition and improvement of equipment which encouraged me to differentiate between music listening and movie watching.


My new (to me) equipment consisted of the Denon 5800/03 and 2 pair of the very revealing Totem model 1 (the fronts are Signature the rears are not but bi-wireable). When i had the 5800 upgraded to 03 audio status 98%, Rick Johnson the Canadian Denon (go to guy) was nice enough to come over to balance my system and he immediatly insisted on certain changes since the Denon allows for 2 sets of surrounds not counting the effects pair.

For movies he had me move the Axiom dipoles (which actually has 2 sets of ports and fire 4 ways (2 ways x 2) forward in the room in front of the listening position (although i can move the sofa up a bit but it's a pain because it affects ingress/egress to the room.

For music he had me wall mount the 2nd pair of Totems in the position that your speakers are in and formerly my Axioms.

There is a shelved closet directly behind the couch (listening position) on which sit my effects pair for the ES/EX or other DSP modes such as 7 channel stereo.

I have invested in both dvd-a and sacd entry level players (denon has 2 sets of analog ins) and find that this placement overall works excellently for music.

For movies if i don't want to move the couch up a couple of feet, i can have both the Axiom and Totem surrounds firing at once which is what i do unless watching T2 or THE HAUNTING, anyway i think you get the picture.


Had i not invested in as revealing group of speakers as the Model 1's I would have been extremely (and was prior to the Totem purchase) happy with the dipole surrounds placed exactly where you have yours.


I know the philosophy's have changed somewhat and someone mentions the word THX an many feel that it is a religion. I DON'T, not that i disagree, it's just that no one is going to tell me that what i've done shouldn't sound good to me.

I hope your going to feel the same way about your setup.


Have fun,

Peter m.
 

·
Registered
Joined
·
3,947 Posts
Quote:
Originally posted by sdurani
All dipoles have positive and negative phase sides. Setting up 4 of them for surround purposes is not difficult at all, as long as you remember to keep similarly phased drivers pointing at each other in order to avoid cancellations. See attached diagram.
Sanjay, when I posted my 'questions', I was being rhetorical. I was trying to make the point that out-of-phase speaker faces must be considered. Of course, your explanation and image are correct.
 

·
Registered
Joined
·
499 Posts
so peter you don't have a problem w/7.1 in that size of a room? I always thought my room would be too small but maybe not, if thats the case then I can't decide to have dipoles/directs or all directs oh well, I just need to try it.
 

·
Registered
Joined
·
499 Posts
also price is a factor because I think for one pair of ADP 370's (paradigm) I could get 2 pairs of mini-monitors, so I don't know if the added cost would be worth it.
 

·
Registered
Joined
·
1,109 Posts
Kingo,

Actually the only dnside to the smaller room is the amount of people who can enjoy this with me.


Cost is, very rarely, not a factor. all i can tell you is that if you decide to go the route that i did, it will work very well, and be limited only by the quality of the speakers and balancing of the system.


goodluck,

Peter m.
 

·
Registered
Joined
·
307 Posts
You can try one back speaker, but most people find they lose the rear effect if the source is directly behind their head. Your brain assumes it's coming from the front centre speaker. Another issue is that not all manufacturers will sell you one speaker. I think the Paradigm mini-monitors come only as a pair.


I had similar issues for side surrounds as you. I had originally planned to use direct radiating all around, but decided to go with the ADP-370's on the sides (they are a little to close to the listeners) and Monitor 3's in the back. I only wish there was more 7.1 source material.
 

·
Registered
Joined
·
1,109 Posts
Hi,

I have a bi-wireable PMC tb1 center speaker that i was thinking of using as a center effects surround. It's physically a pretty large and seemingly powerful speaker.

My question is how would i wire it with the biwire capability? the 4 wires are already there.


thanks,

Peter m.
 

·
Registered
Joined
·
499 Posts
yeah the sides would be pretty close to the listenters heads too, my plan is to buy one pair of mini monitors, use them as sides, and if the surrounds are too over bearing get 370's and move the monitors to the back, but if they work out at the side i'll just get another pair...I wish I would have thought of that sooner.
 

·
Registered
Joined
·
616 Posts
In respecting "the THX standards" Those with THX recommended DD setups

in going to "the source" http://www.thx.com/mod/techlib/surroundEx.html we find stated:

"For optimum results, THX recommends use of two THX Ultra-certified dipole speakers for the back surrounds. However, allowing for customer preference, a pair of direct radiating speakers can also be used for the back surrounds under a new THX specification."


RE: "You can try one back speaker, but most people find they lose the rear effect if the source is directly behind their head." I also found this dreadful, even when I matrixed an EX source. I further found that when I added the 2nd centre rear speaker I had to spread them apart to fill in the back/rear soundstage - a suggestion provided by this Forum.
 
1 - 20 of 21 Posts
Status
Not open for further replies.
Top