Dipole speakers

**toecheese** · **11-27-07, 08:25 AM**

I've been doing too much reading and have convinced myself that I need dipole speakers for my surround in my 7.1 system.

Right now, the Polk in-walls are firing right at the sitting position, so doing the opposite of what they're supposed to do according to THX.

However, there really seems to be a lack of dipoles on the market.

Does anyone have dipole speaker brand/model suggestions? Cost is a big factor, as the amount of sound that comes out of a surround is not that much.

Thanks!

**Bent** · **11-27-07, 09:56 AM**

There's nothing fancy or technologically advanced about a dipole.
Paradigm does a fancy "trick" where they call theirs an "adapted dipole", (ADP) and claim they switch from bi-pole operation to dipole at the cross-over frequency. No magic here, all the do is reverse the polarity of one tweeter and run the reamianider of the speakers in phase.

**drdoan** · **11-27-07, 12:31 PM**

BIC has a very inexpensive surroung speaker set, but, you have to reverse one of the tweeter speaker leads to make it a dipole as it comes connected in phase. I had a set for a while and it did a good job. I don't remember the model number, but, it was advertised as either a surround or front speaker, with 2 opposing tweeters and a woofer in each cabinate. Dennis

**salvasol** · **11-27-07, 01:45 PM**

Quote:

toecheese wrote:

... Right now, the Polk in-walls are firing right at the sitting position, so doing the opposite of what they're supposed to do according to THX... Does anyone have dipole speaker brand/model suggestions? Cost is a big factor, as the amount of sound that comes out of a surround is not that much.Thanks!

Last week I was looking at Polk FXi3 for $225 (pair) here at the shack electronic store

... the question is: How much you want to spend??? ...

I can't beleive it :raped::raped: ... look at this http://www.hometheatershack.com/elec...air_Black.html

**11-27-07, 04:20 PM**

I own a few of the Infinity Beta ES250s, advantage to these is that they can be bi-wired as well as configured for mono-, bi-, or di-pole. Sound great too, either for HT or music applications...

**JCD** · **11-27-07, 06:18 PM**

I actually own Paradigm ADP's.. and would prefer to have a regular direct firing speaker.

To me it made sense back in the day of ProLogic, but I think with DD or DTS, a direct firing speaker makes more sense -- and is easier to set up -- and is cheaper.

Just my opinion of course.

JCD

**brent_s** · **11-27-07, 07:34 PM**

I've never really understood THX's recommendation for dipoles, myself. Possibly it helps enhance their decorrelation effect in the surrounds. It may also be a marketing issue since they pushed dipole's back in the DPL days, as Jacen mentioned. Wouldn't make the licensees or customers too happy if they suddenly reversed field. Personally, with my surrounds (5.1) mounted about 6' up and slightly behind the listening position, they have no problems creating a "diffuse" sound field when necessary and also create pinpoint imaging when called for. Dipoles, by design, are going to be ambiguous with intentionally discrete effects.

It's probably worth noting that Dolby's 5.1/7.1 layout advisor shows traditional monopole speakers in their layouts.

-Brent

**11-27-07, 09:05 PM**

I usually keep mine in bipole mode (and always when listening to music). For HT, when I move the speakers to the side walls in the next room instead of the back flush with the listening position, who knows...I'll have to experiment and see which sounds better. I do like the option of choosing between the 3.

**toecheese** · **11-30-07, 01:43 AM**

Quote:

salvasol wrote:

Last week I was looking at Polk FXi3 for $225 (pair) here at the shack electronic store

... the question is: How much you want to spend??? ...

I can't beleive it :raped::raped: ... look at this http://www.hometheatershack.com/elec...air_Black.html

I have Polks as my current surrounds, but I don't like the design which only has a tweeter on each face, whilst the mid is only on one. I know that the tweeter is more directional, but it just seems kind of lame to cut out the mid. For example, this brand: does the opposite- a pair of mids and a single tweeter.

Polk price is back up to $250.

**toecheese** · **11-30-07, 01:56 AM**

Quote:

brent_s wrote:

I've never really understood THX's recommendation for dipoles, myself. Possibly it helps enhance their decorrelation effect in the surrounds. It may also be a marketing issue since they pushed dipole's back in the DPL days,

I think surround is surroud- it isn't supposed to be direction, except for 'over there'. When playing some THX tests in 7.1 on a friend's setup who had dipoles, the transitions between rears, sides and fronts was much better with dipoles.

I read this article and similar ones and everything I read said dipoles are better as surrounds. I plan on keeping my rears as direct, as they are downward firing and not directly pointed at anyone. But my surrounds are right at the ear of the front row of seats and I think all seats will have an advantage with dipoles.

Quote:

It's probably worth noting that Dolby's 5.1/7.1 layout advisor shows traditional monopole speakers in their layouts.

That is about as simple a site as you can get- and my subwoofer is in the ceiling which doesn't even get past the summary page. They also say you can put the sub anywhere you want.. wrong.

**glaufman** · **11-30-07, 01:18 PM**

Quote:

brent_s wrote:

I've never really understood THX's recommendation for dipoles, myself. Possibly it helps enhance their decorrelation effect in the surrounds. It may also be a marketing issue since they pushed dipole's back in the DPL days, as Jacen mentioned. Wouldn't make the licensees or customers too happy if they suddenly reversed field. Personally, with my surrounds (5.1) mounted about 6' up and slightly behind the listening position, they have no problems creating a "diffuse" sound field when necessary and also create pinpoint imaging when called for. Dipoles, by design, are going to be ambiguous with intentionally discrete effects.

To shed a little more light... one of the biggest reasons THX recommends dipoles and the difuse sound field the present is specifically tone down those discrete effects... their theory goes that if the sound (to the sides or behind) is too pinpoint-able, you'll have the tendency (due to human nature) to glance at the direction the sound came from, which in effect is distracting you from the screen, and therefore from the whole "immersion" illusion experience, and they want to maximize that effect of immersing you in the experience, or "the willing suspension of disbelief" by everything being designed to keep you focused on the screen... their opinion is that 90% of what's coded to come from surround channels is intended to be ambience, and only 10% is intended as as a spatial effect...

not voicing that I agree or disagree with them (my own surrounds are direct fire) ...

**toecheese** · **12-02-07, 02:35 AM**

Some other reasons I've read is that when they're directional, there's a big difference when surround effects happen in relation to seating position. With mains and center, you have three to know from where the sound is supposed to come. With a discrete surround, depending on your position, it can be close, far, in front of you, behind you, etc. Dipoles remove this from happening and actually have a 'dead zone' towards the seating area; you only get reflected sound.

I find some cheapies on fleabay- I'll report later on how they do.

**Prof.** · **12-02-07, 05:47 PM**

Quote:

toecheese wrote:

Some other reasons I've read is that when they're directional, there's a big difference when surround effects happen in relation to seating position. With mains and center, you have three to know from where the sound is supposed to come. With a discrete surround, depending on your position, it can be close, far, in front of you, behind you, etc. Dipoles remove this from happening and actually have a 'dead zone' towards the seating area; you only get reflected sound..

With Tripoles you get the best of both worlds.

**glaufman** · **12-02-07, 08:01 PM**

Tripoles, huh? That's a new one on me...

What do we think of some of th eolder Klipsch that had tweeters in opposite directions (even if they weren't out of phase as in a dipole) and a single mid pointed between the tweeters (check the RS-3)...?

**Prof.** · **12-02-07, 08:49 PM**

Tripoles project the surround sound in three different directions...
Forward and back along the side walls as dipoles do, and out towards your ears with a speaker mounted on the face of the cabinet..
So you get both spatial surround sound and pinpoint direct sound with sound effects at the same time.
I think B&W were one of the first speaker manufacturers to introduce the Tripole surround system...

The RS3 looks like a Tripole but they don't say anything about how many pole it is...
A Tripole has to have a 3way crossover to work correctly, and some speakers like the RS3 only have a 2way crossover..
Nevertheless, still a nice speaker..

**toecheese** · **12-03-07, 11:49 AM**

Quote:

Prof. wrote:

With Tripoles you get the best of both worlds.

I think you jest, but one of the better 'dipole' speaker is a quadrapole- N-S-E-W with the z-axis pointed towards you. I can't find the review of it, but it was stupid-expensive.

As far as best of both worlds, I don't think you can- you either want pinpoint sound or you don't.

**toecheese** · **12-03-07, 11:53 AM**

I found some Atlantic Technology SR-154 speakers for cheap locally and picked them up. http://www.atlantictechnology.com/default.asp?NodeId=82

Mounting is going to be a problem, as my Polks were in-walls. However, it is just for proof of concept. If they work as intended, then I'll probably grab some of the overpriced speakercraft in-walls. http://www.hometheatermag.com/news/110206speakercraft/

Advertisement