Monopole or Dipole surround speakers?

[StevenSurprenant]

First off, here is an article that is worth reading about this subject.

Face Off: Surround-Speaker-Configuration Wars | Home Theater

As for personal experience...

I use Magnepan wall mount speakers for my surround system. For those that don't know, they are thin dipole speakers that are made to hang on the wall. I'll attach a picture to clarify this.

Anyway, I've had these mounted directly on the back wall behind my seating position and I thought they sounded fairly good except that sometimes I could hear the sound coming directly from them. To me, it was somewhat distracting. I got the idea of hanging them in the corners of the back wall and raising them toward the ceiling. I angled them to a 45 degree angle so that they acted purely as dipoles. The result was a tremendous improvement. The surround sound was much more prevalent and the room had much less of effect on the sound.

Anybody experience the same thing? Or do you feel monopoles are better?

[Feanor]

First off, here is an article that is worth reading about this subject.

Face Off: Surround-Speaker-Configuration Wars | Home Theater

As for personal experience...

I use Magnepan wall mount speakers for my surround system. For those that don't know, they are thin dipole speakers that are made to hang on the wall. I'll attach a picture to clarify this.

Anyway, I've had these mounted directly on the back wall behind my seating position and I thought they sounded fairly good except that sometimes I could hear the sound coming directly from them. To me, it was somewhat distracting. I got the idea of hanging them in the corners of the back wall and raising them toward the ceiling. I angled them to a 45 degree angle so that they acted purely as dipoles. The result was a tremendous improvement. The surround sound was much more prevalent and the room had much less of effect on the sound.

Anybody experience the same thing? Or do you feel monopoles are better?

That article is a bit old, isn't it? I though since fully discrete 5.1 came along -- granted, its mentioned in the article -- the verdict had come down on the side of monopole, but maybe there is still debate.

[StevenSurprenant]

That article is a bit old, isn't it? I though since fully discrete 5.1 came along -- granted, its mentioned in the article -- the verdict had come down on the side of monopole, but maybe there is still debate.

It's new to me. That's what happens when you drop out for a while.

[Sir Terrence the Terrible]

That article is a bit old, isn't it? I though since fully discrete 5.1 came along -- granted, its mentioned in the article -- the verdict had come down on the side of monopole, but maybe there is still debate.

No there is no longer a debate. You can see over the last few years that dipole speakers are no longer important when you have stereo signals in the rear. They are slowly disappearing off the market as their popularity wanes. I see more bipolar speakers out there than dipoles.

The latest thing propagated by Dr. Floyd Tool is the monopolar array of loudspeakers in the surrounds like I have in my system. The sense of space is there, the ability to localize and non localize as well is there, and there is no phase issues or timbre matching circuits needed. I been using an array of monopolar loudspeakers for my surrounds for more than a decade.

[StevenSurprenant]

I suppose monopole would work as long as you you don't sit too close to them. I don't have that option though.

[E-Stat]

I suppose monopole would work as long as you you don't sit too close to them. I don't have that option though.

Our resident expert tells us that you need to embrace certain THX standards and ignore others. When you go to the THX website for home theaters, you find the following guidelines. You'll note that the diagrams clearly use dipoles for the SL and SB speakers:

Pic with radiation pattern

"Place the SL & SR speakers between 90° to 110° to each side and 2 feet or higher above the listener. " (that's what you should ignore) and the center should be below or above your monitor (that's what you should follow). Except of course if you should have a perforated screen where you find the obvious suggestion:

"If you have a perforated projection screen, center this speaker both horizontally and vertically behind the screen."

That's probably another case where he would say "ignore" since he can't detect any difference using the 12" mains to center height differential mounting guideline.

rw

[StevenSurprenant]

Our resident expert tells us that you need to embrace certain THX standards and ignore others. When you go to the THX website for home theaters, you find the following guidelines. You'll note that the diagrams clearly use dipoles for the SL and SB speakers:

That's probably another case where he would say "ignore" since he can't detect any difference using the 12" mains to center height differential mounting guideline.

rw

Here's a nice explanation of the differences... A Guide to Bipolar, Dipolar, & Direct-Radiating Monopole Surround Speakers (PART I) - Blu-ray Forum

When I set my rears to act as dipoles, they made the room seem bigger and the sound was more diffuse and less distracting. In my case, the preferred setup.

It's a funny thing...

He talks about comb filtering and such when using more than one speaker for the center channel and how terrible it is, but he uses an array of mono speakers for each side of his back surround speakers and then speaks about the virtues of that set up. In addition, his set up violates, as he has repeatedly and profusely explained, what the recording engineer intended when he created the recording.

[E-Stat]

Here's a nice explanation of the differences..

I've used dipoles since '76.

When I set my rears to act as dipoles, they made the room seem bigger and the sound was more diffuse and less distracting. In my case, the preferred setup.

"Act" as dipoles? What does that mean? I'm thinking from the perspective that a speaker is either a monopole, dipole or omnidirectional. In any event, that is the THX home theatre standard. Take it - or leave it - based upon preference. Ideally yours over that of others.

rw

[Swish]

I think they provide an excellent 'wall of sound'.

[StevenSurprenant]

I've used dipoles since '76.


"Act" as dipoles? What does that mean? I'm thinking from the perspective that a speaker is either a monopole, dipole or omnidirectional. In any event, that is the THX home theatre standard. Take it - or leave it - based upon preference. Ideally yours over that of others.

rw

I know what I said didn't make much sense, but I'll try and explain.

As you know Magnepan speakers are dipole, but the ones I have mount on the walls, which still make them dipole, but there isn't much room between them and the wall to get that spacious sound compared to the more traditional dipoles that sit out into the room. You can refer to the picture I posted to see what they look like.

The ones I used for the rears were pretty close to the seating position and away from the side walls so the listener got pretty much most of the direct radiation pattern from the panels.

What I did was to mount them in the corner of the room and angled them out at 45 degrees from each wall. That way, the sound level off of each wall was equal, but aimed at 90 degrees from each other due to the corner wall. I guess that you could say that it creates a dipole horn effect. From the seating position, the listener sees just the edges of the speakers and not the diaphragm. As you know, the radiation from at dipole at its sides (edge) is at it's minimum.

The radiation effect is a great deal more diffuse sounding and I no longer get the monopole effect which to me was very distracting.

This is total supposition on my part, but I think using the type of dipoles I have in this manner is better than using box speakers designed in a dipole configuration, (in my room) This would take a little experimentation to determine if my assumption is valid and then it would be a matter the personal taste of each individual. Room dimensions would factor into it too, as to which method is preferred. I don't think there is any right or wrong in a persons choice in this matter. Besides, I don't have the option of using side speakers because of windows.

Anyway, I like it and it works for the room it's in.

I hope that explains it.

[E-Stat]

As you know Magnepan speakers are dipole, but the ones I have mount on the walls, which still make them dipole, but there isn't much room between them and the wall to get that spacious sound compared to the more traditional dipoles that sit out into the room.

Got it. Wasn't sure if the surrounds were different than the pic of the fronts. They're definitely dipoles.

rw

[StevenSurprenant]

No officer, there is no blood in my alcohol system.

Now that's funny!

[bfalls]

I think they provide an excellent 'wall of sound'.

I thought side di-poles were supposed to do the opposite. With the sound radiating front and rear an ambient or surrounding effect should be the result.

I've use Klipsch RS-3 side surrounds in my 5.1 system. I also use them as side surrounds in my 7.1 system with monopole rear surrounds. A wall of sound has never come to mind when thinking or listening to the surround channels.

The RS-3s are specifically designed (as well as many other models) with the mid driver facing the listening area and two tweeters (horn-loaded in the case of the RS3s) facing front and back. The result is a null region facing the listening area with diffuse ambient sound front and rear. Diffuse, ambient, surround all sound to be more omnidirectional than a more specifically dimensional wall of sound.

[StevenSurprenant]

I thought side di-poles were supposed to do the opposite. With the sound radiating front and rear an ambient or surrounding effect should be the result.

I've use Klipsch RS-3 side surrounds in my 5.1 system. I also use them as side surrounds in my 7.1 system with monopole rear surrounds. A wall of sound has never come to mind when thinking or listening to the surround channels.

The RS-3s are specifically designed (as well as many other models) with the mid driver facing the listening area and two tweeters (horn-loaded in the case of the RS3s) facing front and back. The result is a null region facing the listening area with diffuse ambient sound front and rear. Diffuse, ambient, surround all sound to be more omnidirectional than a more specifically dimensional wall of sound.

I didn't consider that configuration, but it sounds like it should work well. I suppose it does considering that you like it. It shows that Klipsch was using their grey matter when they made those. BTW, they look nice too.

[StevenSurprenant]

Got it. Wasn't sure if the surrounds were different than the pic of the fronts. They're definitely dipoles.

rw

This is just a little bit of useless information.

Some people use dissimilar speakers for their rear surrounds compared to their fronts. I don't think it's a big issue and not worthy of any concern, but years ago when I first started messing around with surround sound, I had a mixture of different speakers on hand that I used. My mains were Quad ESL's, my center was Bose, and my rears were from Cambridge Sound Works. To say it sounded awful is an understatement. It was so bad that I gave up on surround sound till I finally bought matched speakers many years later.

What's interesting is the effect the rears had on the tonality of the fronts. The rears were at a reduced level so most of the time I wasn't even aware of them. However, I connected an EQ to the rear amp and when I would adjust them, it seemed like the sound of the mains were being adjusted. The point is that if the rears are too different, they will effect the apparent sound of the mains. For movie watching I don't think this is much of an issue at all, but I just found it interesting.

A system doesn't have to be perfect to enjoy it.

The most important thing I learned was how important the center channel was to the whole effect. Going from Quads for mains and a Bose for a center was like listening to two different systems at the same time. I know this all sounds rather ridiculous, but surround was just getting started and I liked to experiment. People didn't even have flat screens back then... Well there was one, but I think it was $20,000 dollars.

Anyway, I'm just rambling again...

[E-Stat]

This is just a little bit of useless information.

In the grand scheme of things, doesn't most of what we discuss fall into that category?

The most important thing I learned was how important the center channel was to the whole effect.

Amen, brother! I confess that as a coherency freak, it is most important to me. I recently upgraded the modest speakers in my HT up a notch. While I didn't change the surrounds, all three of the fronts use the same drivers. There is no mystery whatsoever to me as to why 100% of theatres use symmetric placement of center to mains.

rw

[Sir Terrence the Terrible]

Our resident expert tells us that you need to embrace certain THX standards and ignore others. When you go to the THX website for home theaters, you find the following guidelines. You'll note that the diagrams clearly use dipoles for the SL and SB speakers:

Pic with radiation pattern

THX standards are not quite the same as the THX speakers. Some folks understand the difference between the technical standards in regards to acoustics, speaker set up(as opposed to speaker design marketing), and visual immersion standards. The THX speaker setup works with dipoles, bipoles, and monopolar speakers.

"Place the SL & SR speakers between 90° to 110° to each side and 2 feet or higher above the listener. " (that's what you should ignore) and the center should be below or above your monitor (that's what you should follow). Except of course if you should have a perforated screen where you find the obvious suggestion:

"If you have a perforated projection screen, center this speaker both horizontally and vertically behind the screen."

That's probably another case where he would say "ignore" since he can't detect any difference using the 12" mains to center height differential mounting guideline.

rw

Don't put words any my mouth( for the millionth time). You don't know what the hell I am going to say until I say it.

[Sir Terrence the Terrible]

It's a funny thing...

He talks about comb filtering and such when using more than one speaker for the center channel and how terrible it is, but he uses an array of mono speakers for each side of his back surround speakers and then speaks about the virtues of that set up. In addition, his set up violates, as he has repeatedly and profusely explained, what the recording engineer intended when he created the recording.

Steven, once again you are too stupid to understand that the goal for the front speakers is totally different than the goal for the surrounds. The front speakers should be directional in nature so that imaging is tight and well defined. The surround speakers should be capable of presenting diffusion/spaciousness and directness, something that dipoles cannot do. My surround speakers are capable of doing diffusion, spaciousness and directness, which is exactly what a surround speaker system should be able to do.

Since the speaker system in my signature is directly designed and calibrated like a dubbing stage, it accurately represents what you would expect from Sony, Paramount, Universal, and every other studio that ports its cinema soundtracks directly to home media. I have other sound systems design around the THX, DTS, Dolby model which is the common setup for made for hometheater mixes.

One again you are showing a profound ignorance when it comes to home theater.

[Sir Terrence the Terrible]

I thought side di-poles were supposed to do the opposite. With the sound radiating front and rear an ambient or surrounding effect should be the result.

I've use Klipsch RS-3 side surrounds in my 5.1 system. I also use them as side surrounds in my 7.1 system with monopole rear surrounds. A wall of sound has never come to mind when thinking or listening to the surround channels.

The RS-3s are specifically designed (as well as many other models) with the mid driver facing the listening area and two tweeters (horn-loaded in the case of the RS3s) facing front and back. The result is a null region facing the listening area with diffuse ambient sound front and rear. Diffuse, ambient, surround all sound to be more omnidirectional than a more specifically dimensional wall of sound.

Bfalls,
The RS-3 are a bipolar design, not a dipolar. Their forwards and rearward tweeters are both in phase at all of the frequencies they cover. There is no null in their outputs, just 120 degrees of sound coverage over the operating range of the speaker.

[bfalls]

Bfalls,
The RS-3 are a bipolar design, not a dipolar. Their forwards and rearward tweeters are both in phase at all of the frequencies they cover. There is no null in their outputs, just 120 degrees of sound coverage over the operating range of the speaker.

Well, you learn something new everyday. I did some research and found an explanation of the surrounds on the Klipsch site. They've always performed very well. I can't say I've found any fault with them.

I thought about purchasing the Emotiva ERD-1 surrounds since they're on sale @ $249/pr, but can't see how they would make an improvement. I may purchase them anyway to complete a 5.1 system with my ERM-1 mains and center.

W.D.S.T.


1) Klipsch Wide Dispersion Surround Technology surround speakers take a different approach to surround coverage than dipole and bipole surrounds.

a) Dipole models place drivers out of polarity to create a null on one axis of the speaker. It is popular to sit in the null, thus the loudest sounds come from indirect radiation from the speaker. A dipole, used in this manner creates a diffuse and non-localized rear sound field.

i) Some drawbacks to dipole surrounds include that the rear sound field is not confined to the rear. As much radiation is radiated forward as rearward.

ii) A dipole also depends on other surfaces in the room to reflect the sound to the listener.

iii) A dipole can only create a diffuse rear sound field.

iv) Finally, a dipole is very inefficient at low frequencies, as the out of phase bass cancels.

b) Bipole models place drivers on several faces, with the idea that the radiation is equal in all directions, like a point source.

i) The problem is that the drivers interact, and actually radiate sound very erratically, with a different frequency response in each direction.

ii) The sound field created is not coherent and as a result is not very realistic.

c) Klipsch WDST surrounds are very much like a professional concert array. The high frequencies, made directional by the horn, are arrayed at the proper angles to provide even coverage, or with the same frequency response in all directions. The single woofer is crossed over where it is omni directional, thus creating a system which truly radiates sound equally in all directions.

i) WDST models provide balanced direct and reverberant sound field to listeners. Since the response is the same in all directions, the reverberant sound filed reaching the listeners from other directions, is balanced spectrally with the direct sound, creating a coherent, realistic rear sound field.
Trey Cannon
Klipsch Audio Technologies
Associate Engineer

I use these for the sides in one 7.1 system with monopole rear surrounds.

[E-Stat]

THX standards are not quite the same as the THX speakers.

Who said anything about THX speakers? The pic I linked to clearly is about setup, regardless of whether or not the speaker was a "THX Speaker".

The THX speaker setup works with dipoles, bipoles, and monopolar speakers.

Obviously.

You don't know what the hell I am going to say until I say it.

So, do you agree with the THX Home Theatre speaker recommendation for placing a center behind a perforated screen?

rw

[StevenSurprenant]

Steven, once again you are too stupid to understand that the goal for the front speakers is totally different than the goal for the surrounds. The front speakers should be directional in nature so that imaging is tight and well defined. The surround speakers should be capable of presenting diffusion/spaciousness and directness, something that dipoles cannot do. My surround speakers are capable of doing diffusion, spaciousness and directness, which is exactly what a surround speaker system should be able to do.

Since the speaker system in my signature is directly designed and calibrated like a dubbing stage, it accurately represents what you would expect from Sony, Paramount, Universal, and every other studio that ports its cinema soundtracks directly to home media. I have other sound systems design around the THX, DTS, Dolby model which is the common setup for made for hometheater mixes.

One again you are showing a profound ignorance when it comes to home theater.

I really don't have time to get to you right now, but I will say that it's no surprise that if you would have some excuse. I'll be back, but do me a favor... My IQ is in the middle 130's and while that doesn't make me the next Nobel prize candidate, it indicates that I am not completely stupid. If you disagree with me, then fine, lets talk about that, but name calling is childish and lacks maturity. I have issues with you're "A" type personality and we can discuss that in more detail, but for now, let's act like adults. How about it!

[Sir Terrence the Terrible]

So, do you agree with the THX Home Theatre speaker recommendation for placing a center behind a perforated screen?

rw

We don't use perforated screens, they don't work with digital projectors. I do agree with their recommendation if you have an acoustically transparent screen. THX also has recommendation if you don't.

[E-Stat]

I do agree with their recommendation if you have an acoustically transparent screen.

That wasn't painful, now was it?

rw

[Sir Terrence the Terrible]

I really don't have time to get to you right now, but I will say that it's no surprise that if you would have some excuse. I'll be back, but do me a favor... My IQ is in the middle 130's and while that doesn't make me the next Nobel prize candidate, it indicates that I am not completely stupid. If you disagree with me, then fine, lets talk about that, but name calling is childish and lacks maturity. I have issues with you're "A" type personality and we can discuss that in more detail, but for now, let's act like adults. How about it!

LOLOLOLOLOLOLOLOLOLOLOL, you really are quite funny even if you are not trying to be.