Surround speakers: bipole, dipole or direct radiating?

[ThA tRiXtA]

The title pretty much sums up my question, but I will give a little background info in case it is relevant.

I need to pick up 2 more surround speakers to bump up to my new 7.1 receiver... I currently have two direct radiating left and right surrounds that I have been using with my 5.1 but I've been having troubles locating two of the same speakers to use for the rear center channels.

I have however been able to find a online store that sells bipole and dipole surrounds that match my current setup and I could buy 4 of them so they would all match my system... what is the advantages/disadvantages of a direct radiating speaker versus the bi/dipoles that disperse the sound field to a wider area?

Which type of speaker do you guys prefer for the surround channels, and why?

My room is about 19 x 12 feet, if that changes anything.

Ugh, so many choices and things to think about with a new room setup, who would have thought it would be so involved.

 

[peterL]

Do you watch mostly movies with multichannel information or mostly multichannel audio? My feeling on the subject is that dipoles aren't as good for multichannel audio and that they (dipoles) are only marginally better than direct firing speakers for movies. You can usually get some of the same effects from a direct firing speaker by fiddling with placement and levels.

That along with the fact that the dipole price from most manufacturers is like 1.5 or 2 times more expensive than comparable bookshelves, I feel like direct firing speakers are a no-brainer. What speakers do you have currently (and consequently what are your choices here?)

That said, most of my experience with dipoles came from a friend's fairly budget system (mid-line Polk stuff), so maybe when you spend more money, the dipoles get a hell of a lot better. For me and my PSB setup, I saved the coin and bought B15s for the rears instead of spending nearly double for S50s.

Also, I should say that I have no experience with a 7.1 setup, only 5 and 6.1. When I had a rear center, I was actually using a 2nd center channel speaker. My current living room doesn't allow for speakers behind the couch.....

As an anecdote, my mother bought Mr Magorium's Wonder Emporium for my son and we watched it last night. There is a scene where a magic wooden box is flying around the room and I thought the integration between the B15s (rear) and T45s (front) was impressive. Some rear information should be localized....

 

[RipcordAFF]

Do you watch mostly movies with multichannel information or mostly multichannel audio? My feeling on the subject is that dipoles aren't as good for multichannel audio and that they (dipoles) are only marginally better than direct firing speakers for movies. You can usually get some of the same effects from a direct firing speaker by fiddling with placement and levels.

That along with the fact that the dipole price from most manufacturers is like 1.5 or 2 times more expensive than comparable bookshelves, I feel like direct firing speakers are a no-brainer. What speakers do you have currently (and consequently what are your choices here?)

That said, most of my experience with dipoles came from a friend's fairly budget system (mid-line Polk stuff), so maybe when you spend more money, the dipoles get a hell of a lot better. For me and my PSB setup, I saved the coin and bought B15s for the rears instead of spending nearly double for S50s.

Also, I should say that I have no experience with a 7.1 setup, only 5 and 6.1. When I had a rear center, I was actually using a 2nd center channel speaker. My current living room doesn't allow for speakers behind the couch.....

As an anecdote, my mother bought Mr Magorium's Wonder Emporium for my son and we watched it last night. There is a scene where a magic wooden box is flying around the room and I thought the integration between the B15s (rear) and T45s (front) was impressive. Some rear information should be localized....

I have no personal experience with them. but supposedly the Axiom QS8s are incredible and provide an outstanding rear soundfield. I have heard it described as a "bubble" of sound rather than localizable sounds. Again, no personal experience but they are a big advantage...at least in Axiom's line-up

 

[Exit]

The pair of conventional direct radiating speakers should be used on the back wall of a 7.1 setup. Bipoles, dipoles or others are used on the sidewall where they are intended to simulate sound comming from a wall of speakers like in a cinema. Many people use direct radiators on the sidewall too. If I understand you correctly, I think you would onlly need a set of dipoles, bipoles, etc for your sidewall.

 

[GlocksRock]

I have bi polar for all but my center channel, and I like it a lot. But my side surround speakers are angled to the left and right, wheras my rear surround speakers are bipolar towers, so they don't have the same effect as the side ones. I think both sound good, but for surrounds I would go with bipolar as it makes for a larger sound field.

 

[ThA tRiXtA]

I mainly use my system for movies, and if I were to listen to music on it, it would be a stereo only output...

Thanks for the replies guys, now I know what that term means.

Cheers.

 

[Warpdrv]

What speakers are you using in your system right now..?

 

[TLS Guy]

The title pretty much sums up my question, but I will give a little background info in case it is relevant.

I need to pick up 2 more surround speakers to bump up to my new 7.1 receiver... I currently have two direct radiating left and right surrounds that I have been using with my 5.1 but I've been having troubles locating two of the same speakers to use for the rear center channels.

I have however been able to find a online store that sells bipole and dipole surrounds that match my current setup and I could buy 4 of them so they would all match my system... what is the advantages/disadvantages of a direct radiating speaker versus the bi/dipoles that disperse the sound field to a wider area?

Which type of speaker do you guys prefer for the surround channels, and why?

My room is about 19 x 12 feet, if that changes anything.

Ugh, so many choices and things to think about with a new room setup, who would have thought it would be so involved.

I personally use direct radiating monopoles all round. I find it works fine. It is fine for both movies and music. In the superbly engineered movie, La Vie en Rose, it all comes together beautifully. In this movie, the French engineers make a lot of demands on the surrounds by the way, unlike the unsatisfactory Hollywood crowd. The scenes of sound coming through open side windows are totally realistic. I rate this the best engineered movie I own, and it is a fantastic movie in all respects. One of the best movies for a long time.

 

[ThA tRiXtA]

I currently use the Mission M74i towers, M7C2 center and two M30 surrounds.

I am going to keep on looking for a couple more direct radiating surrounds, as someone mentioned above, the guy who is selling the bipoles is trying to charge an arm and a leg for.

 

[Sheep]

THX standards have direct radiating rear surrounds, and bi/dipole side surrounds.

Also, I would skip 6.1, as I never though it provided a convincing rear sound field.

SheepStar

 

[Warpdrv]

I think direct .vs dispersed bipole/dipole very much depends on the layout of your room...

In my main system, I run direct (Studio 20's) for my side surrounds, as they are a good distance from the LP, the room is huge and they sound amazing.

In my second system, my side walls are narrow, and much closer to the LP and trying to get direct radiating speakers in there would not only be an eyesoar, but hard to get IMO good performance. ADP's (dipole) worked much better in that particular situation for me... I tried both....

I agree with Sheep, but not everyones room is the same, if it was, everyones setup could or would be exactly the same...

 

[Soundman]

I think direct .vs dispersed bipole/dipole very much depends on the layout of your room...

In my main system, I run direct (Studio 20's) for my side surrounds, as they are a good distance from the LP, the room is huge and they sound amazing.

In my second system, my side walls are narrow, and much closer to the LP and trying to get direct radiating speakers in there would not only be an eyesoar, but hard to get IMO good performance. ADP's (dipole) worked much better in that particular situation for me... I tried both....

I agree with Sheep, but not everyones room is the same, if it was, everyones setup could or would be exactly the same...

I agree. This is very important. I believe the rule of thumb is that if your room is not at least 16 feet in length, then 7.1 doesn't add much improvement and in some cases may make it sound worse b/c the the 2 sets of surrounds may be too close together and negate the effect. The layout of the room in reference to your seating position could make a big difference. In my room, the seating position is almost against the back wall (right at 16 ft in length) so, 2 sets of surrounds just doesn't work very well. I've found that the mini-towers I'm using as surrounds offers plenty of sound. I've run bi-poles/dipoles, and quad-poles in the past, but have found that for my room, using direct-radiating all the way around has worked the best. I'm very pleased with my current setup.

 

[croseiv]

Sometimes I wonder if I suffer from bipolar disorder, but direct radiation sound waves at high volume seem to help this condition.

 

[BG3]

THX standards have direct radiating rear surrounds, and bi/dipole side surrounds.
SheepStar

This is correct.

ThA tRiXtA: My room is almost identical to yours. My seating position is very close to the back wall. Given that you rarely want to notice exactly which speaker the sound is emanating from when watching movies, I chose to go with 4 of PSB's C260 bipole/dipole speakers for surrounds. I have them set to dipole and the soundfield is diffuse but very effective. For example, as sound travels arround the surrounds, I no longer have a tendency to direct my attention to a particular speaker thus being distracted from what is going on on the screen. Instead, I now notice the sound and the effect of its movement and my attention stays focused on the movie which produces a much more enveloping experience IMO.

 

[ThA tRiXtA]

Thanks for your opinions BG3

I hope my soundstage will be as non-invasive as you describe yours to be.

 

[BG3]

Thanks for your opinions BG3

I hope my soundstage will be as non-invasive as you describe yours to be.

No problem. I should add that had my seating position been closer to the screen/further from the back wall, I would've followed THX's recommendation for direct radiating rear surrounds. I just didn't want direct sound that close to my ears for movies. On the other hand, for multi-channel music like SACD's, DVD-A, etc. direct radiating or bi-poles seem to be preferred.

To give you a better idea of my layout: I mounted the 4 surrounds 2' above ear height. Also, due to the stud layout and windows, I ended up mounting the rear surrounds approx 1.5' apart center to center. Luckily, this also worked for THX's ASA speaker positioning. Plus, my Onkyo 905 has a setting for this layout. So, the center of the rear surrounds is 3.5' from the main listening position with the side surrounds being 6.5' to the sides & just forward of the listening position. The fronts, center and sub are 17' away at the other end of the room.

 

[ThA tRiXtA]

Now that you mention it, I was going to ask. I am just about to plumb in conduit and cable runs in the wall for my 4 surrounds.

I ended up keeping my original two direct radiating side surrounds, and I managed to find 2 more brand new of the same speaker for the rear surround channels. I considered making a change to bipole/dipole but I didn't want to go through the hassle of having to sell off equipment I already owned that was perfectly fine. I hope I don't regret it.

Anyways, my question is I have often heard the magic position for the side surrounds being 2 feet above ear height and 2 feet back. I cannot unfortunately drag a receiver down in my half finished room right now and test it out for myself because the room is very messy and full of sawdust etc.

How can I go ahead and decide now where those speakers will be permanently positioned before I even get the drywall on? I assume if the side surrounds are 2 feet higher than listening position you would want your rear surrounds to be the same height as well to maintain consistent panning?

Thanks.

Edit: I should say that I am planning not to position my couch against or nearly against the back wall as you have positioned yours... I think I am going to make it so the seating is approximately 10 feet back from the TV so I can get a really nice look at the beautiful 1080P resolution

 

[BG3]

Now that you mention it, I was going to ask. I am just about to plumb in conduit and cable runs in the wall for my 4 surrounds.

I ended up keeping my original two direct radiating side surrounds, and I managed to find 2 more brand new of the same speaker for the rear surround channels. I considered making a change to bipole/dipole but I didn't want to go through the hassle of having to sell off equipment I already owned that was perfectly fine. I hope I don't regret it.

Anyways, my question is I have often heard the magic position for the side surrounds being 2 feet above ear height and 2 feet back. I cannot unfortunately drag a receiver down in my half finished room right now and test it out for myself because the room is very messy and full of sawdust etc.

How can I go ahead and decide now where those speakers will be permanently positioned before I even get the drywall on? I assume if the side surrounds are 2 feet higher than listening position you would want your rear surrounds to be the same height as well to maintain consistent panning?

Thanks.

Edit: I should say that I am planning not to position my couch against or nearly against the back wall as you have positioned yours... I think I am going to make it so the seating is approximately 10 feet back from the TV so I can get a really nice look at the beautiful 1080P resolution

You definitely should determine where your main seating position will be. Then decide where you want your speakers in relation. Next, measure from your corners to each speaker position and notice where your studs, electrical wiring, plumbing, etc. are located. Any of these could very well dictate where your speakers have to go as they did in my situation. Also, pay careful attention to the studs as they may not be in the same place on the side walls. So, you may have to compromise. Also remember with in-walls, you need about 1" buffer to the studs for the clamps. Lastly, since you're measuring w/o sheetrock, be sure to take that into account when you actually go to cut the speaker holes.

Measure twice, cut once....

 

[ThA tRiXtA]

If any studs aren't where I want them to be I will just frame in another stud exactly where I want the speaker to be anchored.

My speakers are not in wall, I'm not sure if we are on the same page or perhaps I may just be misunderstanding what you mean. My 4 surrounds are Mission bookshelf speakers, mainly because I already owned 2 of them.

So my dilemma is do I just go ahead and plumb all four speakers by the 2 feet higher and 2 feet back golden rule and hopefully in the end it will all work out because I have a little flexibility with the extra wire length?

 

[BG3]

If any studs aren't where I want them to be I will just frame in another stud exactly where I want the speaker to be anchored.

My speakers are not in wall, I'm not sure if we are on the same page or perhaps I may just be misunderstanding what you mean. My 4 surrounds are Mission bookshelf speakers, mainly because I already owned 2 of them.

So my dilemma is do I just go ahead and plumb all four speakers by the 2 feet higher and 2 feet back golden rule and hopefully in the end it will all work out because I have a little flexibility with the extra wire length?

My bad, thought you had in-walls. You shouldn't have any problem then. Though, depending on how you plan to mound the speakers on the wall, you may want to take advantage of the opportunity to reinforce that area now while it's easy.

I would recommend visiting the THX site, the Dolby site and even your speaker mfg's site and make a decision based on the info. I don't remember the DTS site having speaker placement recommendations.