Help - Nice small dipole or bipole for HT wanted.


Hi!

I'm trying to clearly decide on which way to go here, "bi or di" - ples for either side or rear surrounds.

Not looking to spend a whole bunch on them either. it would also be nice if they came in either wall or stand mounted configurations, as that has yet to be figured out.

They will probably be powered by the receiver's power plant too.

I've no idea who even makes such a thing, so any help here will be certainly appreciated. Thanks.
blindjim
The Magnepan is a good value and I used them before but I dont know if it is for you given use of a reciever that may or may not have the juice for them........they are not very efficient. BW, Energy, BIC, Boston Accoustics, and quite a few others all offer bi and dipoles, your backs dont need to be anything but standard speaker if that saves you money, some even advise against rear di or bipole speakers period and ony advise standard front fire models while bi and dipole for sides.

Thanks so far. Those names help a lot.

The main questions remaining unresolved, are “Which?” (di or bi), and “Where?” (sides or rears)... and of course, “Who?”.

A good eff rating is gonna be a good thing using the power plant of the Onkyo TX SR 805... 130wpc. .. and it’s a near lengthy run of wire too.

I did suspect the surr sides would be best for the di/bi units. I do have 5 Silverline and two Canton bookshelfs right now.

I had even thought to use a pair of Silverline Minuet directionals somewhere to go with the Sonata IIIs, SR 15, and Centerstage.

The last issue is price. Whichever side surrs, di’s or bi’s, are gonna have to be moderately priced or at least within reason.

BTW, the Silverline monitors do sound pretty full bodied, despite their higher eff rating.

Anything else I should know and other speaker models, are greatly appreciated.
BW and Energy which my father and I both own each can be adjusted with a switch from mono to Dipole, the Energy goes further with adjustment for side, corner, rear placement.
07-18-08: Blindjim
The main questions remaining unresolved, are “Which?” (di or bi), and “Where?” (sides or rears)... and of course, “Who?”.
Dipole surrounds harken back to the analog Dolby ProLogic days and are outmoded with digital surround.

Dolby ProLogic was a primitive surround scheme by today's standards--you have a mono signal of very limited bandwidth (200-5K Hz IIRC) sent to two rear speakers. Surround directionality was very limited and dipole speakers' out-of-phase signals created an illusion of more depth.

But that's not how digital surround works now. Digital surround information is specifically located. I have been running a 7.1 (now 7.2) HT system for over three years now, and there are many films that make use of all the channels in specific ways. For example, during the Quidditch matches in the Harry Potter movies, you hear the golden snitch and the players on brooms flying in all directions, such as flying from behind your left shoulder over your head to the right front.

Furthermore, dipoles create a null area to the sides of the speakers and that's the last thing you want in home theater surrounds. The sound should be seamlessly enveloping.

With that in mind, bi-directional comes closer, but hemispherical or omnidirectional is best because it fills in the back half of the room more completely.

As to the "where," if you are only running two surround speakers, they should be to the sides, preferably on the walls, or positioned where walls would be, about a foot back and a foot or two above where your head will be positioned when watching.

I'm a big fan of 7-channel, however, and encourage you to think in terms of a pair to the sides and another pair to the rear.

If you can't do that for now, put 'em on the sides. You want it to be as seamless an experience as possible, and if you have only two surround speakers behind you, there's too big of a gap between the front and rear soundfields, and the surround effects will be distracting instead of enhancing.

I'm speaking from long experience with this. After having surrounds directly behind the viewing area for 6 years, moving them from the rear to the sides was a revelation.

A good eff rating is gonna be a good thing using the power plant of the Onkyo TX SR 805... 130wpc. .. and it’s a near lengthy run of wire too.
The Magnepans are a bad match on two counts here--they're only 85dB (or maybe less) efficient, and they present a 4-ohm load. Most AV receivers, even the better ones, don't like to go below 6 ohms much and very few can manage an FTC 4-ohm rating. The Mirage Omnisats are incredibly unobtrusive, present 8 ohms, are 89dB efficient, throw a room-filling hemispherical sound field, and yet convey excellent clarity and directionality. They come with a top-notch tweeter--Mirage's own titanium dome design with cloth surround to damp out any ringing. They are fast and detailed yet smooth and sweet. They even include wall-mounting brackets.

The last issue is price. Whichever side surrs, di’s or bi’s, are gonna have to be moderately priced or at least within reason.
The Omnisat v2 Satellites retail at $500/pair but are currently on sale at Crutchfield for $400/pair. Mirage makes a smaller version called the Nanosat that is $250/pair. With the sale, you could get a pair of Omnisate v2 Satellites for side surrounds and a pair of Nanosats for rear surrounds for a total of $650 including free shipping.

They also make a somewhat larger, more efficient (90 dB) version from their OMD line called the OMD-5 that goes lower and is available in piano black or rosewood for $750/pair. The difference in sensitivity between the Magnepan and the OMD-5 is 5dB, which almost quadruples the amount of amplifier power available to reach a given level of volume.
In my opinion, a bipolar's side-null is beneficial in a multichannel setup.

The reverberant energy is a separate event from the first-arrival energy (produced by the front channels), and different priorities come into play.

You do not want the rear channels to stand out as distinct sources; rather, you want them contributing to the ambience and sense of spaciousness, and perhaps the occasional off-screen sound effect. By aiming the null towards the listening area, a bipole can contribute more beneficial ambient energy, relatively speaking, without calling attention to itself as a separate and distinct sound source.

Duke
dealer/manufacturer (nope, I neither build nor sell dipole surround speakers at this time)