Why MUST my Surrounds be Direct Radiating? (1 Viewer)

[John Morris]

Over the past 5 years, I have tried to build a pretty decent primary system for both HT and music. In building my system, I've demoed dozens of speakers and speaker systems. In the end, I've decided that within my budget, the bipolars that I bought sounded best, for movies AND especially music. Stereophile agreed with me, listing my bipolars as Class B... for music, not movies. Sure, there are several direct radiators that I like as well, but none were within my budget.
NOW, time and time again, I keep reading posts which unquestionably state:

bipolar and dipolar speakers are okay for movies, but for music, direct radiating speakers are the best

Many times this opinion is stated as a fact. So, I'm wondering... is this now a fact? If so, in which science or music journal is this written?
My concern is that these blanket statements may discourage folks from even trying bipolar and dipolar speakers and from deciding by themselves, if direct radiating is the sound they like best.
As for me, one of my favorite systems uses dipoles in the rear... and most folks think it sounds pretty good.

If I could afford it, I'd buy it.

 

[Brian OK]

John,

I use dipole ADP 350's and they sound just perfect in my dedicated basement HT.

Saying and listening are two different things seems to me.

You have listened and ....... well. you , like me, have found our preference.

BOK

 

[Brandon_T]

John,
In my very humble opinion, I don't think that you could ever say that "it is a fact" when it comes to making a determination on what type of surround speaker is better. Besides all that really matters is what sounds good to you. To be honest, when I first got my studio adp dipoles, I did not like them. Now after time, I would not trade them for anything and think that it sounds great.. I don't think that people reading blanket statements will affect their judgement. If it does, hey, don't do your research and aren't happy with what you bought, it is your own fault. Just my opinion.
Brandon

 

[Greg_R]

Dipole/Bipoles are great for diffuse effects (rain, clapping, etc.). However, (IMO) they fall short when reproducing direct effects (flybys, person walking behind you, etc.). A perfect example of this is in Terminator 2 during the canal chase. When Arnold rides through the chain link fence, you can hear a distinct 'clink' directly behind you. With dipoles/bipoles, you hear the clink but can't place it in the room. One thing to mention is that direct radiating speakers will image (so there will be a sweet spot for the rears). Dipoles/bipoles don't have this problem...

 

[Craig Ball]

I have klpsch surrounds, there called wide dispersion speakers (WDST) there supposed to give you the best of both worlds. I think there outstanding!! I love listening to the Eagles in DTS sounds great.

Craig

 

[PatrickM]

Direct Radiating speakers are best for 5 channel music as a fact is probably taking too far but I think you'll find that quite a few people do hold that opinion.

I am one of them because of the fact I just don't like the sound of bipolar speakers but that's just my preference.

I think its basically up to the individual to decide what they want and the "experts" be damned since they aren't subsidizing my equipment purchases.

Patrick

 

[John Morris]

IMO, well designed bipoles are excellent imagers... and that shouldn't be suprising, since simplisticly, these speakers are just a pair of direct radiators back to back. Additionally, they also offer the advantage of a huge soundstage. Part of the difficulty with bipoles for music is that they must be carefully positioned. Part of the advantage is that they exhibit a much larger "sweet spot" for experiencing their imaging and soundstage, than do direct radiators.

As for using bi/diples for rear effects, I have absolutely no trouble locating a "clink" in T2, a ricocheting bolt in U-571 or where Drago is as he flies around my head and that of Sean Connery in Dragonheart. If anything, listening to the new multichannel SACD Sacred Feast, Gaudeamus, places you INSIDE a huge Cathedral.

That is not to say that the listening experience with DRs would be any less spiritual, just that for me, bipolars sounded better.

 

[Randy G]

John,
As you've discovered, people have different preferences. If you want to talk studies, most of the anecdotal research suggest that on average, most people prefer the diffuse ambience provided by dipole surrounds. One of the main benefits is that the thrust of the music or movie is more "locked" into the the front hemisphere from which we normally listen. Personally, I am distracted by clinking fences, doorslams, and footsteps coming at me from the sides...in fact, I hate it. Just my opinion. As for music, I prefer listening from the audience as opposed to sitting on stage in the middle of the band or orchestra....kinda cool when I first listen, but gets annoying after awhile.
As for bipolar, I've found that there is a cost to pay for the spaciousness they provide, and that is a lessening of the speaker's ability for pinpoint imaging. There too, it's cool at first, but after awhile gets annoying to me. Everybody's got their preferences.

 

[Bob McElfresh]

John: Well I tend to recommend direct-radiators in the rears because:

- My guess is the sound engineers for the new 5-channel DVD systems are going to assume direct-radiators in the rear. Going direct is a hedge against the future.

- Using indirect speakers makes wall-reflections a large part of the experience. I dont know about YOUR walls, but mine are hardly coated with audiophile paint or sheatrock.

Try this: turn your L/R or just your center speaker backwards to reflect off of the rear wall. Use a SPL meter to level-adjust and then fire up your favorite movie. You will notice a greater depth/spaciousness to the sound (at least with just the center turned around). But after a few minutes, you will notice a lot of sounds are missing something. This is the loss caused by reflections.

 

[Lewis Besze]

I'm one the people who advocate,the direct radiating speakers for surrounds.But I made this conclusion based on a lot of experimentation on my own.I do have bipolar surrounds as well,but they're being used now for the surround back duty[ rear centers].The funy thing is that my mains are bipolar too,[Def Techs BP-10],but my monopole Wharfedale Shaphire bookshelfs are much better match to them then the Def Tech BP-2s,which are also bipolars.

GO figure!

 

[John Morris]

Well I tend to recommend direct-radiators in the rears because: - My guess is the sound engineers for the new 5-channel DVD systems are going to assume direct-radiators in the rear. Going direct is a hedge against the future.Using indirect speakers makes wall-reflections a large part of the experience. I dont know about YOUR walls, but mine are hardly coated with audiophile paint or sheatrock.Try this: turn your L/R or just your center speaker backwards to reflect off of the rear wall. Use a SPL meter to level-adjust and then fire up your favorite movie. You will notice a greater depth/spaciousness to the sound (at least with just the center turned around). But after a few minutes, you will notice a lot of sounds are missing something. This is the loss caused by reflections.[/quote]
All I can say is that if I can help with this persons HT, please let me know.......

 

[Randy G]

Yes, many sound designers use direct radiating speakers all around for the sake of expediency, but so what?! Do you take this as ANY indication that there is some sort of standard as to how they decide WHERE to put certain sounds, microphone technique, what percentage of the soundfield volume is coming from which direction etc. etc.? Sound design is unfortunately, more art than science at this point. Even IF a sound designer chooses to use direct firing speakers, that doesn't mean that he's gonna mix things the way I like. Sure, he COULD mix things so that ambience predominates the rear channels, but that doesn't mean he WILL.With dipole surrounds, it's now MY choice, because that's what *I* prefer. When there are more mixing standards, I might then change my mind, but at this point, I hold out little hope.
As for real-world dipole mounting considerations, YES, you DO have to have sidewalls available to bounce the sound off of. Some folks can't accomodate that, and therefore should use direct radiating speakers. And as for audiophile paint or sheetrock, what the heck does THAT mean???

 

[Dan Driscoll]

John,
I have dipoles for rears, specifically for music. I prefer the spaciousness created by dipoles when listening to 2 channel recordings in 5 channel mode. IMO dipoles more accurately recreate the sounds of an ampitheater or concert hall expressely because of the reflections.
OTOH, I do think that for DD5.1 or DTS source material, particularly movies, direct radiators would be a better choice. This is because of how the sound engineers mix the audio, creating specific sound paths and points, rather than areas.. Dipoles and bipoles simply cannot recreate the point presence of a monopole.

 

[Mike__D]

Not that I'm an expert here, but from what I've read in the past, dipole/bipoles were matched well with Dolby Pro-Logic content. Since it was mono in the rears, the Di/bipoles helped create the "surround" effect. Look at Video Essentials, this DVD looks as though it was originally made for Pro-Logic (I beleive it came on LD first, so that would be why) and they updated it for DD. Anyway, in VE, the animations have dipole/bipole speakers.

Now with DD 5.1 and DTS, direct speakers are supposed to be used since you should located were the sounds are coming from. I can't comment on multi-channel music since I've never heard it.

 

[Ron-P]

I started with dipoles for my rear surrounds and then sold them off to upgrade. Before I upgraded I tried a pair of directs and found them to be a better choice. They handle diffused sound very well like the dipoles, but I also prefer the direct sound they produce.
Give'em both a try and keep what you prefer.
Peace Out~

 

[Bob McElfresh]

RandyG: refering to "audiophile paint and sheatrock" was a bit of a joke. All the cable-arguments about how one speaker wire sounds different does get a little silly around here. If all our speakers were reflection-type, we would likely have arguments about what brand of paint creates a more accurate reflection, what color gives a "warmer" sound, should we use nails or screws in the sheatrock, how many nails/inch should we use, etc. (So you are saying I should not give up my day job? ) Sorry about the obscure joke.
JohnM: I'm not sure what kind of help you are offering. If you want to send me some equipment, sure!
(I should learn to not post while suffering a head-cold).
I own DefTech bipolar towers. After I got them, two big questions came to me:
- If bipolars sound good, why is the center speaker a direct-radiator?
- If bipolars sound good because of the back-reflection, how come so many room-treatments involve stopping reflections?
Trying to answer these questions taught me a lot about acoustic theory, psycho-acoustic theories, and industry trends for rear-sounds.
I'm happy to discuss my findings/opinions, but it could get a little obscure. Let me know if you want the details behind my recomendation for rear speakers.

 

[Jim_C]

As Craig mentioned, the Klipsch surrounds use WDST technology to try and cover both direct radiating and dispersed sound. With my RS-3's there's a woofer aimed directly at the listening position and a tweeter on either side is angled away from the listening position.

I personally find this to be a very effective solution. The speakers work very well for both music and movies. I hooked them up to the main channels as an experiment and was very impressed with the performance. Yes, they sound different from true direct-radiating speakers but still very good.

 

[John Morris]

- If bipolars sound good because of the back-reflection, how come so many room-treatments involve stopping reflections?

Maybe because room reflections can cause bass cancellation and room induced frequency peaks and nulls. And yes, all speakers regardless of type exhibit these problems.

 

[Shane Martin]

John,

I prefer direct radiators as well.

Now if you want my opinion on why here goes.

5.1 is supposed to be discrete sound from discrete portions of the room and a diffuse rearsoundfield goes against that philosophy IMHO. I want to hear discretely in the room where the sound is coming from not a big void of sound in the back of the room.

Now for the surround back speakers I prefer the multipolar route.

 

[Larry B]

Merc:
I should begin by stating the obvious: One is free to use anything one likes (provided one can afford it. ) Now that that's out of the way....
The soundstaging and imaging that are possible with truly "high end" audio equipment is nothing short of outstanding, and virtually unimaginable to those that have never experienced it. Anything other than direct radiating speakers (bipoles, dipoles) completely negate this effect. It is for this reason that you have read the kind of reviews you referred to in your post.
For less than hi-end equipment, which provides less than stellar soundstaging and imaging, I suppose it's possible that bi- or dipoles might generate some sense of spaciousness, albeit somewhat phony. In some ways this is akin to the "concert hall" and other DSP's on some receivers: phony, but not necessarily unpleasant.
Does that help at all?
Larry