REAR surrounds (for EX/ES) direct radiating or dipole? (1 Viewer)

[MichaelDDD]

Simple question. (Heh...as if there is one when it comes to speakers!)

For the REAR surround speakers (for DD-EX/DTS-ES) are you supposed to have direct-radiating or dipoles?

I currently have a set of Axiom QS-8s for my surrounds. Do I get another pair of them or a smaller set like the M2i?

Thanks.

 

[Richard_B]

It's all preference.

If you think you are gonna be playing multi-channel music DVD-A or SACD then I would say to get the direct-radiating for the back and use the dipoles for the side surrounds on a 7.1 setup.

 

[Phil Iturralde]

I followed the recommendation from Dolby Labs Listener's Guide to DD-EX website ...

If it's good enough for the DD/DTS-5.1/6.1 Mixing Engineer, ... it's good enough for me!!! Basically reproducing the same sound surround environment that the music/blockbuster soundtrack is Mixed with!!!

Phil

 

[MichaelDDD]

Thanks, Richard and Phil.

Phil, what a reply! Complete with graphics and multi-colored text too!

Gotta luv that. I do plan on checking out some DVD-A/SACD discs...but being that I already own one set of QS8s, I guess I'll be purchasing another. Thanks a lot!

 

[Edward J M]

Phil:

I just love your posts. They are so....analytical. Graphics, color, flawless logic backed by self generated data. You're an asset to the forum.

Anyway, FWIW, I run 7.1 with dipoles at the side and monopoles in the rear, but otherwise exactly like the DD-EX chart Phil provided.

Probably more important than having identical speakers all around is having them timbre matched. My system, like Phil's, uses the same exact tweeter and midrange driver in all speakers. Timbre panning is flawless and seamless, as I'm sure Phil's is too.

I just prefer the dipole for the side surrounds as it provides an unparalleled diffuse sound field with uncanny depth and sound effect placement. It is at once both localizable, but also seems to float in space rather than being pinpointed from an exact spot.

For the rear, monopole all the way as you want a solid rear soundstage, like the front stage.

 

[wes18]

I've been trying to find out how to wire two rear center surrounds but to no luck. I have a Yamaha RXV1200 and it has output for one surround center speaker. People I've talked with and articles I have read make it seem that using 2 rear surrounds are the way to go. Do I only use one wire and splice it to the two or do I use 2 wires and combine into the receiver. Still learning the connection stuff.

 

[MichaelDDD]

Well, I'm sure that Axiom M2i is timbre-matched to my main L/R and Center; it uses the same 5.25" driver and tweet.

Now, I'm confused again....do I want just timbre-matched or do I want the SAME speakers as my surrounds?

 

[Edward J M]

Mark:

You can wire them in series (doubles impedance) or parallel (halves impedance). As long as your AVR doesn't have trouble with either load, you're OK. Series is probably safer for the amp.

Michael:

I think the enthusiasts who use identical speakers all around are in the minority. The bipole/dipole design is unique for a reason; it provides what many consider to be optimum dispersion characteristics for side surround use.

The same can be said for the center channel and the towers, etc. They are all optimized for their own particular application.

It is really a matter of personal preference. For SACD and DVD-A, some prefer the monopole. FWIW, I switch my surrounds to bipole (vice dipole) for SACD and DVD-A, since the dipole setting can sound funny on certain music passages. But I always use the dipole setting for HT.

 

[Doug Brewster]

"I think the enthusiasts who use identical speakers all around are in the minority. The bipole/dipole design is unique for a reason; it provides what many consider to be optimum dispersion characteristics for side surround use.

The same can be said for the center channel and the towers, etc. They are all optimized for their own particular application."

I think I hear swords being drawn, hammers being cocked, and trumpets sounding "Charge !"
There are indeed personal preferences about this, but those who have them are all absolutely right.
You'll get everything from "Timbre-matching is all that matters", to "all 7 should be identical or it will never be seamless". If you like what Phil says, go with it (no doubt it will sound great), but others will say that his use of that "timbre-matched Center" will degrade the sound quality.

Personally, I believe that different speakers in a system have different requirements and therefore they not only don't have to be identical, but need to be different (though timbre-matched). I'm absolutely right, of course.

 

[MichaelDDD]

Heh, Doug, I still don't know what to get.

In the past, on the rare ocassion that I listened to 2-channel music thru Circle Surround or other DSP effect, I've thought it sounded pretty good thru my dipole surrounds.

I must admit that besides a real movie theater, I've never heard a DolbyEX or DTS-ES system in person, so I can't say that I have a preference for direct or dipole rear surrounds.

I'm leaning towards direct, out of price considerations, but I've already spent $$$ on the rest of the rig, why cheap-out now if I don't have to.

So, the thread rolls on.

ps
Doug, nice to be discussing speakers again.

 

[DonnyD]

Mark....
If your rear centers are 8 ohms each, run them parallel for a 4 ohm load since the Yam 1200 will run it quite well. YOU DO NOT NEED TO flip the switch (on the rear of the rec) to 4 ohm. I would run the rear centers on small..........
As some have mentioned, two rear centers are a good way to go and it gives a little more "surround " effect according to placement. I went to 2 rear centers because of placement issues with only one and really enjoy it. I have a Yam RX-V1 and have had absolutely no problems with the load........ do a search and you'll find more info on the Yam receivers running differnt ohm loads......

 

[Ed O'Neill]

STOP the bus!

First off I think Phil put up some great info...
however it is directly copied from dolby site, he even told you that.

I was told you should use the same as you front center or if you want "two rears" the should be the same as your front l/r. Again using the theory of timber matching. I agree that the two rears is the logical choice but remember it will only make the sound more spacious. Don't forget that the rears are mono...meaning the same sound comes out of both rear speakers at the same time.

Having said all that here is some advice...

Michael DDD,
Most manufacturers speakers are timber matched and that is the most important thing. It is more important than what type of surrounds you use...mono pole, dipole, or bipole.
I have heard various reports on what types and placement.I went with direct (mono pole), but you could always buy a speaker that is tri-pole meaning you can switch between sound formats and see which is best. I suggest you go to www.dolby.com and read and read and read.That is what I did.

Phil,
You should seriously upgrade your sides(surround) to be di-pole that is what is the best recomendation dolby gives!

Mark Wessel,
Like other people have said you can run them in series or parell in your situation.However in most situations You need to have an external amp(like me). I recently bought a 2 channel 100 watt amp which is the same impediance and wattage as my reciever and also the same brand. That is how I was instructed

To all,
Goto www.dolby.com you will learn a lot.Even when you thought you knew it all.

BTW- The list of movie produced in DD ex is very small, so far..

Terminator 2 - Judgment Day
102 Dalmatians
Atlantis
Finding Nemo
Mission to Mars
Monsters Inc
Signs
Toy Story 2
Unbreakable
Bats
Chicken Run
Gladiator (2001 Oscar Winner for Best Sound)
The Haunting
The Legend of Bagger Vance
The Ring
Die Another Day: Bond 20
James Bond: The World Is Not Enough
The Terminator
Spy Kids
Austin Powers in Goldmember
Austin Powers: The Spy Who Shagged Me Released
Blade 2: Bloodhunt
Lord of the Rings
Seven
The Astounaut's Wife
We Were Soldiers
Hollow Man
Punch-Drunk Love
The Messenger: the Joan of Arc Story
Cast Away
Minority Report
Say It Isn't So
Someone Like You
Star Wars: Episode One
Star Wars: Episode II- Attack Of The Clones
The Fight Club
X Men
E.T. The Extra Terrestrial
Jurassic Park 3
The Bone Collector
The Caveman's Valentine
Pitch Black
A.I.
Harry Potter And The Chamber Of Secrets
Harry Potter and the Sorcerer's Stone
See Spot Run
The Art of War
The Exorcist-The Version You've Never Seen Released
The Perfect Storm

Independent Films
RXmas
The Dangerous Lives of Altar Boys

Just my two cents,
Ed

 

[Phil Iturralde]

And he said THX is investigating solutions to that problem -- maybe some kind of automatic switching!

My favorite DD-5.1/6.1 Demo that easily demonstrates the 360-degree sound effects directional path is ...

1) Video Essentials - Walk Around the Room Voice Demo

You can visualize the voice location, pitch, and directional sound path using mono-poles!!!

With di-poles diffusing characteristics, and limited high frequency (usually less than 10 kHz @ your 'sweet spot' due to the tweeters being off-axis from you), ... the sound not only changes it's pitch and tone, but bloats a bit (diffused) and widens just as the sound starts moving from the Right Front Channel towards the Right Side Surround, etc.

I personally like the pin-point personal voice sound size precise location, ... as the voice moves, ... like a person walking around you talking in the 360-degee pattern. Interestingly, I'm fortunate enough to hear it sound (dispersion & pattern) like it was meant to sound in my 20' x 30' HT/family room, ... since it was encoded (dispersion & pattern) using identical mono-pole speakers in the 5.1 Mixing Studio.

If it's good enough for the DD/DTS-5.1 6.1 Mixing Engineer, ... it's good enough for me!!!

So, when I upgraded to 6.1, I bought another JBL S26 for my Rear Center Channel (wired in-series) and now, ... I Force ON the Matrix 6.1 MODE with ALL my blockbuster DD/DTS-5.1 DVD's with glorious results!!!

Just MHO and thoughts,
Phil

 

[Ed O'Neill]

Phil,

I am not about to start a war.

Signed,
ED

 

[Kevin C Brown]

I'll just put in a few cents worth.

a) S&V has a good article in the current issue that talks about 7.1 speaker setup.

b) I personally think that the type of rears you choose is a lot less important than the surrounds. But I also think like some of y'all, that the rears should be identical to the surrounds for the best sound field.

c) I personally have used bipolars, omnipolars, and direct radiators for surrounds and rears. I personally prefer bipoles/omnipoles.

I found that monopoles for me were waaaay too localizable. I had them about 12" above ear level. Surrounds about 7 ft away, and 1 ft behind the listening position. Rears form an equilateral triangle about 5 ft on a side. Now, we all probably know that the solution for me was to place them the recommended 2 - 3 ft above ear level. I didn't want to do that, because then, like for dipoles, you are relying on off-axis, reflected sound to get to the listener. If you've ever looked at a freq response plot, off-axis response is never that great, with the highs rolled off, and roughness in the midrange due to comb filtering between direct sound and reflected sound.

With bipoles and omnipoles, you get direct, well imaged sound, but with reflected sound that is designed to support the direct sound waves, but which also mellow localization.

But each person has to judge best what works in their own system, room, material, and personal preferences.

I will say that I did prefer the direct radiators for multichannel music though. Floyd's Dark Side was sublime... But, I have exactly 3 SACDs, 1 DVD-A, and a few hundred DVDs.

 

[MichaelDDD]

Wow, excellent posts, Phil and Kevin.

I've had bipoles (only bipoles) as side surrounds for years now...I've had good results and like their sound.

I've never had rear surrounds before...damn, I'm so confused! That bothers me...usually w/electronics, I examine and decide...not so easy w/this though!

 

[Doug Brewster]

"I must admit that besides a real movie theater, I've never heard a DolbyEX or DTS-ES system in person, so I can't say that I have a preference for direct or dipole rear surrounds."

I suggest you listen to one...but the difference would be best judged in your own home. Usually, if you're considering purchase, a decent B&M shop will let you take something home to try it out.
In theory, the idea of dipoles as "side surrounds" makes sense to me. The idea of conventional rear surrounds also makes more sense to me than dipoles...Just thinking in terms of dispersion characteristics. Have no actual experience with this.

"I'm leaning towards direct, out of price considerations, but I've already spent $$$ on the rest of the rig, why cheap-out now if I don't have to."

I agree with your thinking...Meaning that if cost is the deciding factor, you would be better off spending more and getting what you want...Otherwise you're likely to be dissatisfied and end up getting them later. Of course, any decision should be based on home testing as opposed to dreams, thoughts, and theories.

I too am pleased to be talking speakers again. In the previous thread, I was only trying to "accentuate the positive" in an arena where the negative was the only voice. Glad to be on speaking terms with you. Enough said.

Ed O'Neill,
"I am not about to start a war." You didn't.
This did:
" For the REAR surround speakers (for DD-EX/DTS-ES) are you supposed to have direct-radiating or dipoles?"
You only got caught in the cross-fire
Opinions about proper speaker configuration are a matter of personal dogma and once the question gets asked, the war begins.

If you think Phil's response is heated, try starting a thread with either of the following:

A) "Is there a break in period for speakers (or any other components)?
B)Do expensive cables make much difference in the audio quality?

 

[Ed O'Neill]

Doug wrote,

Ed O'Neill,
"I am not about to start a war." You didn't.
This did:
" For the REAR surround speakers (for DD-EX/DTS-ES) are you supposed to have direct-radiating or dipoles?"
You only got caught in the cross-fire

Thanks for the laugh Doug..It made my day!

Now I would just like to add this....

My system uses switchable dipole/bipole "surrounds". My rear speakers are identicle to my front L/R, that is what I was told when I set up my system way back. I plan on upgrading my "surround" (sides) to multipole(all three modes)when I have the money.

I have had surround sound since the early 90's, you must remember there was only pro-logic at the time. I will not get just mono-poles for my "surround" sides. Now having said that I have approximately 300 vhs tapes that I have no intention on getting rid of.

My parents owned a video store in the mid 80's- early 90's. Damn BLOCKBUSTER VIDEO .When they closed the store My parents, my brothers and I picked through and took what we wanted,then we flea marketed out the rest. So there is the reason I will never get rid of the di-pole option in my system. You may want to keep this in mind if you have old vhs tapes. Now I know that some of you younger guys have never even seen a vhs tape...LOL.

Phil,
I must admit I haven't visited the dolby site in a long time.I have always just directed people to the site because as you showed it is a wealth of knoledge. That is where I learned almost everything I know about set-up.

When I say this it is the truth...there was never any mention of mono-pole being a bettter option for dolby digital back when I bought/set-up my system up. Now since moving into my new home 3 years ago I started re modeling a room to be a home theater. I got sick 1 month into the project I then got into a major acccident and now I'm sick again. Having said that I have just finished the theater room , well I am actually waiting on the interconnect cables and speaker wire from parts express. So to be honest I was planning on looking at their site again for tips for setting up my 7.1 system (6.1 with external 2 channel amp)and thanks to you and www.dolby.com . I have
learned some valuable info. I however need to read a little more. So a bigTHANKSto you Phil.

Talk to you guys soon,
Ed

 

[Kevin C Brown]

Here is an interesting take:

Link Removed

Note the comment about THX-certified dipoles that are required to deliver flat freq response to the listener, but yet with a diffuse sound. I am not even sure I've *seen* a lot of THX-certified dipole speakers though. I have seen freq reponse plots of "typical" dipoles, and most of them suck. The highs are rolled off, and the midrange freqs are too rough and not smooth.

Just looked through HT mag's '03 eqp directory, and Atlantic Tech, Jamo, M&K among others make THX certified dipoles.

 

[Phil Iturralde]

They should at least be of the same brand and of similar design.

That's why I have six Identical speakers anchoring my Fronts, Side, Rear Center Surround Channels w/timbre-matched Center (SVS 25-31PCi of course! ).

Once you've experienced that 360-degree surround effects with ... "the same acoustic polarity..." around you, ... then you'll know why I recommend following Dolby Labs recommendation linked above! You can hear the artistic precise pin-point directional surround effects that were carefully encoded by some of the Academy Award Sound Engineer's in your blockbuster DVD's - which not only adds to the visceral emotion tied to the on-screen action, but also elevates the illusion that the blockbuster Movie was designed to Warp, or take, or fly you!

Phil