AV question - dipole or bipole for rear speakers

OK I know that this isn't really an AV forum but I thought I'd ask all the same.

What would people recommend for rear surround speakers - positioned on the wall about 7 feet from the floor, the listening position is about three feet infront of the back wall.

I was trying to work out the benefits/drawbacks of standard (bookshelf type) speakers vs dipole and bipole ones.

I should say that the system is 5.1 Dolby and DTS (not 6.1 or 7.1)

Thanks

 

Don't worry, this forum's description explicitly includes AV.

I find ordinary speakers (and at ordinary heightor a little higher) work fine. I'd suggest they are of a similar character to the front ones. If you purposely want to make localization of surround sounds difficult, then mount them higher or use speaker types you suggest, but I'd never say that was absolutely required.

Another reason for slightly higher mounting might be to clear furniture and bodies, but other than for that reason one leaves the area of hi-fi too much for my taste. (Have you ever heard anyone's ordinary stereo with speakers mounted up by the ceiling in the corners? - wow, really trippy hippy sound and difficult to localise, but a long way from hi-fi IMHO)

 

Normal speakers, then angle them as you prefer...

 

Opinion is divided – some (Antonio) like direct radiators, others like bipoles whereas THX still advocate dipoles. There's even a fourth (and possibly ultimate solution) of tripoles from the likes of M&K.

Personally I do like a more diffuse rear sound (especially for movies) so I would tend to recommend a bipole or dipole – the good news is that there are rear speakers (Monitor Audio for example) that can operate as bipoles or dipoles depending upon how you wire them. So check out the Monitor Audio Bronze or Silver FX rear speakers.

Matt.

 

Normal speakers, facing each other, either side and slightly behind the listening postion, placed up high, angled slightly downwards is what I use. Also, they are B&W CDM2SEs, which complement my Nautilus 805Sigs very nicely.

I personally would only recommend bi/dipoles when you have Pro-Logic Only. If you have Digital then go with normal speakers.

See here for Dolby's recommendations http://www.dolby.com/Consumer/Technologies/DD/FAQ_DolbyDigital.html#16

They also do a great setup thing here http://www.dolby.com/Consumer/HomeEntertainment/Setup/

 

I have a pair of M&K K4 tripoles and they work very well :-



From the M&K web page :-

The K-4 Tripoleâ„¢ allows multichannel audio enthusiasts to enjoy M&K's exclusive Tripole technology at its most affordable price ever in in a very compact size. The Tripole design provides a very even "illumination" of sound throughout the listening area, meaning listeners can sit anywhere in the room and hear superior imaging and surround quality from the surround channels. The K-4 speaker is specifically designed for surround channel use in a home theater environment, and shares all of the technology and is timbre matched to the rest of the K Series.

 

Tom,

just make sure your rear speakers match your front ones. If this precludes using Dipole/Bipole, then so be it. But try to use the same all the way around.

 

Thanks everyone for the advice, links, etc. It certainly seems that matching the other speakers tonally is more important than the type of speaker.

Anyone got any Sonus Faber Wall's for sale?

 

I heard the Walls, they are not that good as surrounds, look for used Concertos or at least Concertinos, I have Signum as surround for my EAII fronts...

 

dipoles for movies. direct for music was what i was told. i use mission 78's for my rears - well sides - well left sides at the moment as the wire i have won't reach that far. must get my arse in gear and break out the drill to fix them to the wall.
cheers


julian

 

Just to amplify a little - if you go for the ordinary speaker-type solution, MHO that the back speakers need to be the same character as the fronts doesn't mean they need to be identical. For example, I have floorstanding ported Linn Espeks at the front and little bookshelf Katans at the back on brackets, plus a sub. My girlfriend commented that the backs sound as if they are producing real deep bass, whereas in reality its coming from elsewhere in the system. But the backs do use the same tweeters and mids as the front (AFAICT) so they definitely are in the same family. Probably the processor allows you to define the rear speakers as 'small': if so, the bass is definitely routed elsewhere.

If this is all true for you, then IMHO the back speakers only need preferably to be in the same family, not identical twins. This might help if money is limited or you can't see how to put floorstanders on wall brackets

 

Of course the ideal is to use exactly the same speakers at the same distance all around, but I find that the same brand and same tweeter smaller speakers work as well, thats why I replaced the Concertos with Signums as surround...

 

Just a couple of further thoughts.

On the tonal matching side I would say that this is less of an issue if you are using diffuse rear speakers (bipole/dipole) than it is with a direct radiating rears.

Also, the distance that the rears will be from the listening position can also be relevant – if they are fairly close then you may well find a bipole/dipole will work better – if they are a fair distance back then direct radiators may be good.

I'd be tempted to maybe loan a pair of Monitor Audio Silver FX bi/dipoles plus a pair of direct radiators (something like Dynaudio 42W's) from a dealer and to give them both a whirl.

By the way, it's interesting that Dolby recommend one route and THX another – shows that even the so called experts can't agree on this subject.

Matt.

 

Never have heard a truly holographic sound field created by different speakers.

Dipoles are surely just a THX fudge for domestic use, and really built their reputation back in the days of Dolby Surround and bandwidth limited surround channel. I would have thought they were totally unsuitable for multichannel music reproduction.

 

Dipoles with restricted bandwidth were popular in the Pro Logic days but modern dipoles have a much fuller range..

I don't see them as unsuitable for multichannel music as much of the rear speaker information is just ambience anyway in an attempt to broaden the soundstage.

Dark Side of the Moon is a rarity as the SACD is mastered to place different instruments and sounds at each speaker but most multichannel music isn't like that.

I prefer bipole type speakers at the side or rear if space is restricted, which it does seem to be in cases where the settee is shoved back against the wall

 

Hi Ian - with your quote above, my settee is about 2 foot away from the back wall, where do you think is the best place to put my newly aquired bipoles..? - behind me, or at the side...

most people seem to suggest at the side, but I don't want to start dfrilling holes needlessly just yet...

 

My settee is against the rear wall and I had my bipolar speakers on the side walls a couple of feet in from the back wall and also a couple of feet down from the ceiling.

It is difficult to experiment with rear speaker positioning unless you have a couple of strong patient blokes to stand around and hold them for you but IMO side walls are best unless the distance between the opposing side walls is too great

 

yeah, cheers for that - I guess I'll try with the side walls, the only issue I've got is the door frame on the side, this will mean that one of the speakers (well, both as I'll have them the same distance from the back wall) will be less than a foot from the back wall...I'll double check this tonight tho...!

 

Wm uses Monitor Audio Gold refernce rears in Dipole config, They do, do a pretty fair at the back for 5:1 and surprising good bass too. Matt, I may be selling soon if your interested. T.

 

I was faced with the dilemma of di/bi-pole speakers against normal speakers. I had read that it depends on whether you are listening to multi-channel music or home cinema. As I couldn't make up my mind, and had positioning problems, I bought a pair of floor standing, upward firing, omni directional speakers. They are similar to sonab but made by T&A. I am very impressed. They go a long way to solving the problem of being sat off centre and getting an earful of one speaker but not much of the other. They are also hidden by the lamp tables. This has a high WAF as they sport that lovely fake teak vaneer so in vogue in the late 70's & early 80's

Rod