Diepoles or studio 20's??

[madmax1]

Today i went into my local HiFi store and was looking at studio 60's for my front end. Right now i have 20's there, but was gonna move them to the rear. So i told this to my salesman and he said that would be a mistake? He told me to go with the dipoles instead. Now i do 50% movies and 50% music. My system is as follows- Paradigm studio 20's in front, cc-470 center, servo 15 sub, KLH in the rear--- this is why i want to upgrade!! So if anyone could tell me why which one is better to go with, thanks in advance!! The Diepoles vs putting the 20's in the rear????? THX!!!

[paul_pci]

I'm not going to tell you which one is better, but I am going to make the observation that buying dipoles when you have perfectly suitable speakers for the rears amounts to spending unnecessary money.

[jasmit]

Why don't you try it with the 20's and if you're not satisfied, get the dipoles? An awful lot of people use 20's as rears and are very happy. I don't have to tell you how good the 20's are. At the risk of being unfair to your saleman, I agree with paul; I suspect that he's angling to make a few more bucks off of you.

[Woochifer]

Sounds like the sales guy's trying to sell you an extra pair of speakers. There's no reason whatsoever why you can't or shouldn't use the Studio 20s as surrounds. If you plan to use your speakers for both movie soundtracks and 5.1 music, then it's actually preferable to go with direct firing surround speakers.

Dipoles will diffuse the sound in the surround channels, which will help with ambient sound effects, but it will also render directionless the surround sounds that benefit from good stereo separation. IMO, dipoles are a relic from the Pro Logic days when you had monophonic sound getting fed into the surround channels, and movie soundtracks were primarily about mimicking what long arrays of surround speakers sound like. With multichannel music and an increasing number of movie soundtracks, you want the separation and directionality in the surrounds. The way to go with that is direct firing speakers.

The key to making it all work is the placement and positioning. The diagram below shows the reference 5.1 surround speaker placement. You should try to position your speakers in a similar arrangement. Dolby also recommends that surround speakers get raised about 2' above ear level and pointed directly towards one another. This preserves the directional cues, while diffusing the sound just enough to create an ambient effect with more monophonic surround effects.

http://www.axiomaudio.com/global/images/diagrams/dolby_digital_pro_logic2.jpg

[kexodusc]

Woochifer nailed it. In my opinion dipoles and bipoles are more destructive to the pinpoint imaging capabilities and coherrent sound stage. I owned a set of Paradigm dipoles briefly, and should have returned them sooner so I didn't take a hit selling them on ebay. I'm one of many people who was more than happy using Studio 20's as surrounds (and rears).
I know some prefer them though, and report great results. I think it's a personal taste thing. To you the dipoles might be better. The cheap solution, as mentioned, is to try the Studio 20's out first. If you're not satisfied, then you can consider the dipoles.
But I'd tell your salesperson to take a hike in the meantime...I'd be willing to be that the majority of home theaters DON'T use dipoles or bipoles, and that the majority of home theater owners are just fine with that.

[Sir Terrence the Terrible]

Woochifer nailed it. In my opinion dipoles and bipoles are more destructive to the pinpoint imaging capabilities and coherrent sound stage. I owned a set of Paradigm dipoles briefly, and should have returned them sooner so I didn't take a hit selling them on ebay. I'm one of many people who was more than happy using Studio 20's as surrounds (and rears).
I know some prefer them though, and report great results. I think it's a personal taste thing. To you the dipoles might be better. The cheap solution, as mentioned, is to try the Studio 20's out first. If you're not satisfied, then you can consider the dipoles.
But I'd tell your salesperson to take a hike in the meantime...I'd be willing to be that the majority of home theaters DON'T use dipoles or bipoles, and that the majority of home theater owners are just fine with that.

Not big on dipoles these days, but bipoles are perfect IMO for both music and movie soundtracks. Surround Sound Magazine did a listening test that was published about a year ago. It compared the sound of bipoles, dipoles and monopoles. This was a blind test, and no one, not even the person conducting the test knew which was which. The bipole speaker was continually preferred over the other two speaker designs. The listeners in the test thought that the monopole was too direct, and the dipole was too diffused. They found that the bipole had the best balance of direct to reflected sound.
What you don't want is pinpoint imaging in the rear. The rear soundstage for both music and movie soundtracks should reflect what is heard both on the soundstage, and in the concert hall. Both of these venues favor a more ambient surround than a couple of monopoles can provide even though it is the favored design for most hometheaters.

This test may not reflect what many here prefer for the surrounds, but at least it gives the bipole design some legitimacy for playback.

Do not listen to the salesman, give your existing speakers a try in the rear, and make your decision after listening.

[kexodusc]

I've never paid serious attention to bipole vs. dipole performance...they were both similar to me upon initial observation. What in your estimation are the benefits of bipole over dipole?


What you don't want is pinpoint imaging in the rear. The rear soundstage for both music and movie soundtracks should reflect what is heard both on the soundstage, and in the concert hall. Both of these venues favor a more ambient surround than a couple of monopoles can provide even though it is the favored design for most hometheaters.

I'm a little surprsided here Sir T, this is a contradiction to comments you yourself have made in the past. We've discussed multi-channel audio before, and agreed that if the artist in multi-channel music does indeed intend for pin point imaging in the rear then that is exactly what you should have. I'm not so sure I'm as confident in the ability of bipoles to deliver this, though my experience is admittedy limited.

Much like depth and staging are built across the front, using direct radiating speakers should provide for similar effects throught the surround field. Admittedly not as diffuse, but then you're trading one set of features for another. For music/movie setups such as mine , from experience I can say that bipoles and dipoles fail in this application. That said I can see how for many ambient soundtracks bipoles could be preferred.

I fully intend to explore bipoles in the near future. I've already got a cabinet design and some crossover ideas done. If this works out, I should be able to have my cake and eat it too.

I think it's quite interesting that a lot of 2-channel stereo guys actually prefer the bipole speaker offerings from various manufacturers...

This really is an age old question in home theater. Pretty much all major publications have performed similar tests, and for movies, I often see the bipole/dipole speakers recommended. Then every once in a while, you find someone with tastes like myself who find it more destructive than convincing. Blind tests aside, my own all important tests just don't make it jive. And this doesn't even touch the perceived value in spending often double on bipoles over standard direct radiating speakers. And we arrive at the personal preference thing again. There really is no universal right or wrong.

I think it would be great if Dolby or DTS decided to pick a speaker format and go from there. I wonder, when they make the soundtracks, do they "build in" the appropriate level of surround diffusion? If so on what reference system? This, I suspect would answer a lot of questions?

[madmax1]

Gonna get the studio 60's and put them up front, then put the 20;s in the rear like i planned. Just couldnt beleive how pushy he was on the dipoles!! I told him i got all my other stuff from him and still pushing those dipoles. Kinda sucks cuz hes the only one close to me selling paradigms. Oh well thanks everyone for your input!!!

[Sir Terrence the Terrible]

I've never paid serious attention to bipole vs. dipole performance...they were both similar to me upon initial observation. What in your estimation are the benefits of bipole over dipole?

Easy question to answer. Bipoles keep all of their drivers in phase, so no worries about low bass cancellation, or fuzzy images. Dipoles cannot create phantom images, bipoles can. The dipoles rear half is out of phase which prevents phantom imaging from forming. Bipolar speakers can offer a very wide dispersion pattern, and depending on design and crossover point, can be a constant directivity, equal frequency response over a very wide area. Dipoles display uneven frequency responses in some directions, and relatively flat in others (when measured in the direct field). Since bipolar speakers don't flip the phase, voice matching them with the front speakers is a lot easier than with dipoles, which will never match a phase correct speaker.


I'm a little surprsided here Sir T, this is a contradiction to comments you yourself have made in the past. We've discussed multi-channel audio before, and agreed that if the artist in multi-channel music does indeed intend for pin point imaging in the rear then that is exactly what you should have. I'm not so sure I'm as confident in the ability of bipoles to deliver this, though my experience is admittedy limited.

Actually it's not a contradiction if you don't assume a bipolar speakers don't image well. They in fact image as well as a direct radiator (depending on design), but over a much wider area. For instance, if I sit exactly in between my bipolars, I can clearly hear a EX effect phantom images across the back of my room, no matter where they are located. This is a effect shared by monopolar designs. The difference is it sounds more spacious, but no less direct. Dipoles cannot do this, and perhaps monopoles might do this TOO well. With Dts's specialized artistic mixes, images panned to the rear are as clear and easily perceptible as with a monopolar speaker, except it sounds a little more spacious. The images are not fuzzy and indistinct like with a dipole, but perfect clear and easy to hear.


Much like depth and staging are built across the front, using direct radiating speakers should provide for similar effects throught the surround field.

Keep in mind, the front soundstage and rear soundstage have two different purposes that most be joined together seamlessly. The front stage offers direct cues, and the rear ambient cues. In most instances you want your front speakers to have controlled dispersion(which enhances imaging), but you want your rears to have very wide dispersion which contributes to spaciousness. What you don't want is your speakers flipping the phase response to acheive the spaciousness, as this type of speaker would only be good reproducing fuzzy ambient information. Also what you don't want is a speaker so direct, that in some cases it will pull attention from the front soundstage which often happens when monopolars are used in the rear. Bipolars offer the perfect balance between these two extremes.


Admittedly not as diffuse, but then you're trading one set of features for another. For music/movie setups such as mine , from experience I can say that bipoles and dipoles fail in this application. That said I can see how for many ambient soundtracks bipoles could be preferred.

I think it depends on the design of the bipolar speaker. I happen to own a pair that faces the bass/mid driver forward just like a monopole, but faces the upper mid/tweeters at 45 degree angles. Another design has two set of bass/mids and tweeters facing 180 degree angles from each other. Each type of design will reproduce a slightly different sound. Before they guy who built my speakers did so, he allowed me to audition both types of designs. I didn't like the back to back design as much as the angled designed which sounded tighter, but ever so slightly less ambient. The design I choose was much better at creating phantom images between them than the other design, at that was what won me over. I also compared two monopoles against what the design that I chose. I liked what I chose much better for the reasons I have outlined earlier.




I fully intend to explore bipoles in the near future. I've already got a cabinet design and some crossover ideas done. If this works out, I should be able to have my cake and eat it too.

You go boy, eat that cake!!


I think it's quite interesting that a lot of 2-channel stereo guys actually prefer the bipole speaker offerings from various manufacturers...

Ehh, two channel sound is so dry IMO, that you need artifical reflections to juice it up, and make it sound more realistic. Bipolar speakers in the front makes two channel a more emmersive experience.


This really is an age old question in home theater. Pretty much all major publications have performed similar tests, and for movies, I often see the bipole/dipole speakers recommended. Then every once in a while, you find someone with tastes like myself who find it more destructive than convincing. Blind tests aside, my own all important tests just don't make it jive. And this doesn't even touch the perceived value in spending often double on bipoles over standard direct radiating speakers. And we arrive at the personal preference thing again. There really is no universal right or wrong.

Actually there is a universal right and wrong. The examples come from the dubbing stage, and the concert hall. In the dubbing stage mulitple monopolar speakers are located along the side and rear walls. The various arrival times from the speakers creates a comb filtering effect. This comb filtering creates the sonic signature of spaciousness, and this is the environment film soundtracks are created in. There no pinpoint localization in the rear, and it functions quite differently than the front array.

A concert hall has alot of irregular surfaces, ornamentation, baffles, facades to balconies, and some smooth surfaces. All of these surfaces creates reflections and diffusion. What happens on the stage is launched into the hall. The stage is the direct field, and the hall is the reverberant field. There is no precident for pinpoint imaging in the reverberant field.

Both of these two examples can be directly translated to hometheater. In hometheater you have your direct field(the front speakers) and your reverberant field(the surround speakers). When addressing the acoustics of your hometheater you use acoustical foam to control reflections around the front speakers. You use diffusors or hemholtz resonators for the rear to control reflections evenly within the room. You are essentially creating a direct, and reverberant field. Playback speakers should mimick that example. You should use controlled dispersion speakers for the front array, and a wide dispersion pair for the rears. That is what is normally recommended by installer training organizations such as CEDIA and THX.. Any variances from these examples reflects ones taste in what they prefer to hear, and not what is recommended industry wide.


I think it would be great if Dolby or DTS decided to pick a speaker format and go from there. I wonder, when they make the soundtracks, do they "build in" the appropriate level of surround diffusion? If so on what reference system? This, I suspect would answer a lot of questions?

They really have picked a speaker format. It's called the ITU B-775 format(see Wooch's diagram). Unfortunately this recommendation doesn't square with the layout of the dubbing stage, but is more desireable for music applications. The recording industry as a whole recommends the ITU setup. Since hometheater only uses two speakers(I think four would be better) for the surround field, the ITU setup is the best compromise to join these two different systems together(music and film)

[kexodusc]

Great reply, thanks...
Doesn't the ITU speaker suggestion call for monopoles though?

[Sir Terrence the Terrible]

Great reply, thanks...
Doesn't the ITU speaker suggestion call for monopoles though?

Since the recommedation is really for recording studios and not film, then your answer is yes. However I use the ITU setup with my bipoles, and it works just as well. I do not think it would work with dipoles though.