Monopoles vs Dipoles for Surround

john.michael · 08-24-2004, 12:56 PM

I am starting to design my home theater. It will be in a allmost dedicated room (wife will have a small office) with 26.2 ft by 12 ft. I will use it mainly as a HT (10% music). As the room is big enouh I might go for 7.1.

My plan, regarding speakers is/was all B&W except for the SW (recommendations anyone?):

- N805 or N803 as front L&R;
- HTM1 as center;
- N805 on the sides;
- SCM 1 on the back;

I might have jumped the gun as I already bought a Nautilus B&W 805s only to find out after a little research that I might yield better results if I had gone for a line that has dipoles for the surround speakers (which the N800 line has not).

B&W (and DTS)argues that the future is monopole surrouund. However, THX and Dolby disagrees and B&W´s new 700 line has dipoles...

In short, for me it realy does not make much sense to expend all that money and not get a great cinematic surrund experience.

Any thoughts or sugestions to the newbie on the dipole vs monopole issue?

Many thanks

GregBe · 08-24-2004, 01:10 PM

There is no right answer. It is all personal preference and you will hear strong arguments in both directions by people who are experts. I personally like a more diffuse sound for movies. I don't think either method is as exteme as the arguments you will hear. I dipole system is stronger in envelopment, but you still get a good degree of directional effects. A monopole system is stronger a directional effects, but there is still a good degree of envelopment. Most arguments that you hear favor dipoles for cinema and monoples for multichannel music.

Greg

08-24-2004, 01:32 PM

Greg nailed it perfectly.

In my persomal experience, I have chosen to optimize for MC music. As such, I have found that I prefer to have monoples and further, I mount then on stands slightly behind the listenning position and to the sides, such that the tweeters are at about ear height.

I find that this works well for MC music, particularly when there are instruments mixed to the rear as opposed to just ambience, BUT, it still does a decent job of envelopement for film.

I do find that I do not care for diffuse sounding surrounds, dipoles or not for MC music.

Now, were I to decide I wanted to optimze for film, I would go up high on the side walls, and likely go with dipoles.

BGL

ChrisRuh · 08-24-2004, 01:50 PM

Don't rule out bipoles.

In addition: From what I understand it is not as important to have your rear surrounds match your fronts (in terms of speaker line). I've had bipoles for about a month now and completley love them for DVD movies. They are quite different from monopoles and I noticed a difference immediately.

08-24-2004, 02:18 PM

Ahh yes....can't forget Bipoles!

While lots of users are enjoying their systems with dissimilar rears, I do think that its a good thing to stay within the same line for all five (or 6 or 7 now, I guess) speaker positions, if you can do so.

I had a Heinz 57 system for quite some time, but when I finally acquired the last piece of the puzzle (a B&W CC6 to go with my 604s and 601s) I was really happy with the overall sense of envelopment that a matching said provides.

I would probably agree that it is less important to match the rears than the front trio, but when $$$ allows, its worth going for the full Monty.

IMHO, YMMV, AFAIC....

One more thing....the OP asked about a Sub. I use a HSU 1225 with my B&W's and am pretty happy with that. Lots of fans of SVS here (they were not around when I got my HSU). Either will give you great bang for the buck. And while there has been lots written about matching subs to mains, getting complimentary crossovers, ported vs. sealed designs, in most cases, you can get decent results with almost any high quality sub.

The latest S&V has a nice article from Tom Nuisane, and couple issues ago, SGHT (what's their new name...????) had a couple Sub articles from Keith Yates. Very good reading.

Oh, and whats your sub budget?????

BGL

**HTF Ads**

john.michael · 08-24-2004, 02:33 PM

In order not to " lose" the Nautilus 805´s and keep timbre, it seems that the best strategy is to plance them higher up then " usual".

My sub budget is about US$ 1.8k (which I was planning to spend on the B&W SW until I was introduced to the HSU, SVS Velodyne Brands).

Phil Iturralde · 08-24-2004, 02:38 PM

Quote:

Monopoles vs Dipoles for Surround

HT is my priority and based on my research around 1997/98**, I used identical speakers for my Fronts, Sides & Rear Center Channel Surround locations w/timbre-matched Center in my 20' x 30' w/10' high vaulted ceiling HT/family room.

**The following Dolby Labs 2000 5.1-Channel Guideline replaces their original "Dolby Digital Professional Encoding Manual" that I read around 1997/98 but both made the same recommendation for the Mixing/Monitoring Studio speakers ...

5.1-Channel Production Guidelines - Production Environment (2000 Dolby Laboratories Inc; all rights reserved.)

Quote:

3.2.1 Front Speakers (pg. 24)
Multichannel sound systems add a center speaker to the Left/Right pair used in stereo systems. To promote good imaging, all three should be identical, just as conventional L and R stereo speakers must be matched. If all three cannot be the same model, the center speaker may be a smaller model from the same product line.

3.2.2 Surround Speakers (pg.25)
Whenever possible, use the same speakers all around to achieve uniformity. If this is not feasible, the surround speakers may be smaller than the front speakers but should maintain the same character; i.e. they might be smaller speakers from the same manufacturer.

So, since my blockbuster DD/DTS-5.1/6.1 DVD's are encoded using identical direct radiator speakers, it made sense to me to buy and setup my HT playback system(s) to reproduce that very same sonic, Mixing/Monitoring Studio 5.1/6.1-Channel, discreet and seamless surround environment to playback those DVD's in my HT/family room.

Interestingly, ... later around 2003, Dolby published the following guideline ...

5.1-Channel Music Production Guidelines - The 5.1-Channel Music Mixing Environment (2003 Dolby Laboratories Inc; all rights reserved.)

Quote:

3.2 Monitoring (pg. 16 & 17)
3.2.1 Reference Monitors

Note: All five loudspeakers (L, R, C, LS, RS) should be identical.

One of the main differences between 5.1-channel setups for music and those for home theater playback is the type of speakers used for the surround positions. The goal of surround reproduction in the cinema (accomplished using multiple speaker arrays) is to provide surround playback to large audiences.

Surround effects are often very diffuse, ambient soundscapes. Dipole speakers are sometimes used in the home environment (rarely used in movie theatres) at the surround locations to help create the wide wash of sound created using an array of speakers in the cinema.

However, in 5.1-channel music production, as well as in films, the surrounds are sometimes used for distinct placement of featured performers. Accurate reproduction in this case requires the use of direct-firing speakers that match the overall characteristics of the front speakers. Use of matched direct radiator or monopole speakers in 5.1- channel music production is recommended for achieving the greatest control of level, timbre, and image location. Due to their dependence on null spot positioning, reflective front and rear listening room walls, and preference of a diffuse surround field, dipole speaker monitoring is not ideal for critical 5.1-channel music production. It is recommended that all five speakers (L, C, R, Ls, Rs) be identical ...

Looks like I'm basically set for both formats, though my Surround placements is optimized for HT! Both Movies and 5.1 Music sounds glorious!!!

Phil

08-24-2004, 02:51 PM

Great post Phil. I have pasted links to the "5.1 Music Mixing Environment Guidelines" article on a number of occasions.

IIRC, that same document also suggests placement of the rear channels such that they are not much higher vertically than the reference position, and arranged to be between 100 to 120 degrees horizontally.

Which works well for me since I do not have a room that allows for any sort of wall mounting

BGL

08-24-2004, 02:53 PM

Quote:

My sub budget is about US$ 1.8k (which I was planning to spend on the B&W SW until I was introduced to the HSU, SVS Velodyne Brands).

That kind of $$$$ spent on HSU or SVS means that you best live in a home with a very, very solid foundation

BGL

john.michael · 08-24-2004, 04:50 PM

Phil and Brian,

Thanks for your posts (particularly you, Phil). It most definetly makes LOTS of sense to follow the production specs.

As a matter of fact this also solved another question that I had which is wheter I should use the Nautilus 803´s or 805´s in the front. Will go for the 805´s, keep all the speakers identical and save some $$$.

It also seems that I could save some $$$ with the HSU or SVS.

Any recommended models?

You guys seem to have discarted the Velodyne. Why is that?

Many thanks again,

JMS