Question Monopole, Bipole or Dipole for rear surrounds in 5.1.4 in 6m x 4m room?


Active Member
This is my layout

The Amber speakers are the ones I need to buy. The SL and SR will be stand mounted bookshelf style speakers at ear height.

The green ones are existing Definitive Technology UIW bp/a (bipole) in the ceiling which were my surround backs, but will now become my Top Rear Atmos speakers (moving from 7.1 to 5.1.4).

The blue front speakers are M&K 850 on floor stands.

Questions as follows
  1. Note that the only seating that really matters is the centre couch containing the MLP. The other seats are only used very occasionally. Given this, is my placement of the amber SL/SR OK? ie just behind the MLP and about 2.7m/1.8m respectively from the MLP.
  2. Should the amber SL and SR be monopole, bipole or dipole? Note that I am doing Atmos.
  3. My budget is up to £1000, although I would be happy to pay less:). Any suggestions for specific speakers?
  4. For the front Atmos modules that will sit on top of my FL and FR speakers (simulating Top Middle), any suggestions for which to get (budget up to around £500)? Note my ceiling is 2.4m high and flat. How important is it to ensure they are complementary to my Def Tech in ceiling bipole speakers, or is this not relevant?


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Active Member
I forgot to mention, whilst I am initially going for 5.1.4 I may upgrade to 7.1.4. If so I would probably relocate my existing in-ceiling Def Tech bipole speakers from their current SL and SR positions (not shown in in the drawing above) into the wall behind the middle couch (probably directly under the 2 green in-ceiling speakers). So ideally I would want to make sure my new surround speakers are complementary to these Def Tech bi-pole speakers (which were not cheap!).


Active Member
I have read loads of long threads on this subject and the general consensus is that monopole is preferred in "large" room and di/bipole in a "medium/small" room. The problem is no-one says what they mean by large or medium or small.

My gut feeling is that with the dimensions of my room I should go for di/bipole, especially given I only watch movies, and most surround effects are not directional.

But then I worry about whether this will interfere with my Atmos speakers, especially given the rear pair will also be bi-pole.

Any thoughts?


Active Member
And now I have just found this, in relation to a room of similar size to mine

"If you can always sit in the sweet spot, and there aren't any other critical listeners, in a small room like you describe, go with the direct radiating surrounds.
If you have multiple critical listeners, or want to have similar sonic experiences in multiple seats, direct radiators won't be ideal.

Either way is a compromise for some listeners in some seats. You have to choose which compromise matters less to you"
Which makes perfect sense to me, even though it contradicts most of what I have read. On this basis, given I now generally watch alone or just with my wife (ie only the middle couch is used), I should go for monopoles focused on my MLP.

Decisions, decisions...


Active Member
It's fantastic when no one replies, yes? I've posted photos and diagrams and months later, no replies. I'm still looking at upgrading my own 6.1 setup to 7.1.4 and trying to find a way to make it work in my room, which has real problems with a sliding glass door in the back of the room and a half bathroom 2/3 the way back and a fireplace on the other side just behind the listening couch area. Most houses from the 1970s aren't ideal for home theater....

In any case, what I CAN tell you is that most of the advice out there isn't really very helpful anyway for the simple reason self-appointed "experts" just parrot information from Dolby Laboratories and most will therefore tell you that bipoles and dipoles are worthless for Atmos and that is just RIDICULOUS NONSENSE. Dolby are the same people saying that these "enabled" speakers are best for ceilings that are only 7-8 feet tall and there is nothing WORSE for dispersion than a ridiculous ceiling "bounce" speaker. It will almost never sound like it's coming from the ceiling. You will hear it mostly from the speaker and it will blur the soundstage. So if these jokers at Dolby can tell you with a straight face that a crappy "bounce" speaker is GOOD while something like a high-wall mounted dipole or bipole is automatically BAD, quite frankly, I can't take them seriously. I highly doubt that the people that make these recommendations are the real tech guys. It's far more likely it's marketing telling the tech guys to give something they can shove up our noses.

Dolby are the same people that told us for YEARS that side-mounted dipoles or monopoles mounted above ear level were ideal for the home. Now suddenly they're total crap. I understand there's a bed level and a ceiling level, but what SHOULD be IDEAL in a home is a bed level and a "height" level. In other words, what should work GREAT is having a side surround ear level with a side surround height level above it (that ironically is THE method used for Auro 3D!) After all, what is the difference between the ceiling and a foot or two below the ceiling in terms of audio? NOT MUCH. The width of the ceiling effects might be wider, but how is that a "bad" thing and how is it any different from any number of seats in a real theater that aren't sitting dead center anyway?

What I'm thinking of doing in my own room (which has bipole PSB S50s on the side walls just behind the couch 2/3 up the wall currently as the side surrounds is using those for middle height/top in Atmos/X/Auro, adding a second set at ear level for the new side surrounds, putting matching speakers to my L/C/R (PSB B15) at the same height as the S50 height speakers on the bookshelves on either side of my 92" projection screen (these will be FRONT "height/top" and also "presence/dialog lift" speakers with a Yamaha receiver. In other words, they will not only function as a height channel with Yamaha, but get the dialog to come right out of the screen (L/C/R are below the screen currently). The S50 units have the same drivers as the B15 so everything matches. I can't find any S50s on eBay currently, but I can get more B15/B25 type speakers or a close match Alpha if need be and use them in the rear surround or side surrounds (swap) (rears are currently B15 also at ear level).

There is NO REASON why bipoles or even dipoles wouldn't work as side surrounds in an Atmos setup. Wider dispersion and even nulls don't get rid of ALL directionality and having two heights with or without pin-point dispersion is still going to give an interesting surround effect. Which works better is still probably going to be room dependent. The ONLY way to know for sure is to set it up and try it. What gets me is the absolute lack of blogs/magazines/articles that do just that, TRY IT OUT and report back what works and doesn't work for various size and shape rooms rather than just taking Dolby's blanket advice (go bouncy speakers!!! NOT!)

It's very disappointing to see so many people and sites just fall in line with whatever Dolby says when their bouncy speaker advice is such crap. 7.1 still sounds great with or without bipoles/dipoles, just different. Adding height/ceiling speakers doesn't make bipoles/dipoles suddenly stop working. Huge arrays in giant theaters aren't going to pinpoint image that well anyway, so why should they at home? What's happening on-screen should be the priority. Who is to say what exact "accuracy" is for off-screen sound effects? Does it matter if the rocket went directly overhead or slightly to the side overhead? Not to this listener. As long as it sounds good....

Thus, I'd be interested to hear what results you get with whatever you decide to try. I like to read about real rooms, not Dolby brochures.


Active Member
I'm not sure why this posting did not trigger any responses (except yours) but I did end up creating a newer post here, which was a bit more successful.

I've been living with my new 7.1.4 set up for several months now and am very happy with it. The front atmos ceiling bouncers are good enough for me, and saved loads of grief and cost vs ceiling mounted speakers.

And to be honest that is the key; what is good enough for you is good enough. Regardless of what the experts say. Frankly I suspect my set up is overkill for my room and my ears, which are not very sophisticated. It is very easy to focus more on the technology than on what works for you.

I would definitely recommend going second hand where you can, as that will save you loads of money and has worked well for me. And before buying anything, critically challenge yourself as to how good your hearing is. Will you really be able to appreciate the difference between a good 5.1 and a mediocre 7.1.4 set up?

Good luck

Seriously Ltd

Distinguished Member
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We use bipolar and tripolar surround loudspeakers in many of our installations.

Tripoles are our preferred choice. Monopoles work perfectly well but a tripolar speakers creates a fantastic immmersive experience. Very large rooms with seating for over 50 people we would consider using arrays of monopole speakers.

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