To Monopole or Multi-pole: That is the question?

[Soundman]

Hi All,
I know this topic has been addressed numerous times. For surrounds, what type of speaker to use?: monopoles or multi-poles, meaning bi-poles, dipoles, quad-poles, etc. I know this topic is one of the most debated subjects in home theatre, but here's the situation. I've heard that if the speakers are fairly close and you can get them above ear level, then a monopole speaker may actually sound better. If the speaker is, say mounted on the way, several feet above the listening position, then a muti-pole speaker may be better, creating a more enveloping sound field. The reason I've brought this up is b/c I was in favor of going with a multi-pole speaker, until I realized just how much the reflections in my room has been effecting the sound quality. I believe the multi-poles have caused more reflections in my room and since things tend to already be a bit brighter in this room, now I'm leaning more towards a mono-pole solution. There isn't a lot more I can do to treat the room. Ideally, I would say, just treat the room, eliminating the reflections, and get what you prefer. I may not have that option in this case. This room is a main living room and this is where the wife-approval factor comes into play. Anyway, I just wanted to get some others opinions on this issue. Is it true, that in this type of environment a monopole speaker may sound better since my surrounds will only be a few feet away? Are the reflections in the room negating the advantages of a muti-pole speaker? I'm interested to hear what others experiences have been. I'd appreciate any feedback.

 

[jostenmeat]

hi. Contrary to what I first believed, it appears that bipoles/dipoles are easier to place. That monopoles take more careful placement, and when successful, creates a more solid/stable soundfield according to their proponents. fwiw, speakers like dipoles depend on reflections for proper effect AFAIK. And you are right, this is often debated, and it seems to pretty much boil down to taste. I would personally love to try some bipole surrounds someday, but I run monopoles for sides and rears. The tweeters are placed about a foot or so above ear level. Sounds great. If you try monopoles, point them at the listener. If it seems too localizable, you can point them slightly away. Trial and error, and again, personal taste! GL.

 

[Soundman]

hi. Contrary to what I first believed, it appears that bipoles/dipoles are easier to place. That monopoles take more careful placement, and when successful, creates a more solid/stable soundfield according to their proponents. fwiw, speakers like dipoles depend on reflections for proper effect AFAIK. And you are right, this is often debated, and it seems to pretty much boil down to taste. I would personally love to try some bipole surrounds someday, but I run monopoles for sides and rears. The tweeters are placed about a foot or so above ear level. Sounds great. If you try monopoles, point them at the listener. If it seems too localizable, you can point them slightly away. Trial and error, and again, personal taste! GL.

Thanks for the input. I guess the main concern is that if reflections are already a concern for the room and di-poles are dependent on reflections for the effect, could this be a problem? In other words, could room acoustics ruin this effect? Am I better off going with monopoles?

 

[nova]

Hmmm.... I have had quite a number of systems using direct radiating rears,.... but the best sounding system is the one I have that uses a Bi/Di rear (as in the woofers are Bi-Polar, and the tweeters are Di-Polar).

Not saying this is the best for everyone, and of course this system cost way more than most people care to spend.

I really like the Bi-Di for side surrounds,...though I do prefer direct for rear surrounds. So I guess that depends on if you are looking at 5.1 or 7.1

 

[Soundman]

Hmmm.... I have had quite a number of systems using direct radiating rears,.... but the best sounding system is the one I have that uses a Bi/Di rear (as in the woofers are Bi-Polar, and the tweeters are Di-Polar).

Not saying this is the best for everyone, and of course this system cost way more than most people care to spend.

I really like the Bi-Di for side surrounds,...though I do prefer direct for rear surrounds. So I guess that depends on if you are looking at 5.1 or 7.1

This will be for a 5.1 setup. I may expand to 7.1 at some point, but just 5.1 for now. The surrounds will be directly to the sides of the listening position.

 

[Soundman]

Does anyone know if there is cause for concern if using a bi/di configuration in a more reflective room, seeing as they are based on reflective sound? Will a more reflective room (my treatment options are limited), cancell this effect or take away from the intended design?

 

[jcPanny]

Surround speaker options.

I would opt for the dipole speakers for the "side" surround channels if you have side walls on which to mount them and prefer movie listening. Direct radiating speakers are usually preferred for multi-channel music listening.

Some of the bi-pole type speakers would also be a good option for a more disperse surround field if you don't meet the mounting and/or reflection requirments for di-poles.

Also keep in mind that the reflections in your room (or lack there of) will effect all of your speakers. Even furniture like pillows, drapes, rugs, bookcases, etc. can help provide absorption and dispersion and tame some of the reflections in your room.

 

[Soundman]

I would opt for the dipole speakers for the "side" surround channels if you have side walls on which to mount them and prefer movie listening. Direct radiating speakers are usually preferred for multi-channel music listening.

Some of the bi-pole type speakers would also be a good option for a more disperse surround field if you don't meet the mounting and/or reflection requirments for di-poles.

Also keep in mind that the reflections in your room (or lack there of) will effect all of your speakers. Even furniture like pillows, drapes, rugs, bookcases, etc. can help provide absorption and dispersion and tame some of the reflections in your room.

Good information. I won't be wall mounting these speakers. I have stands I was going to use for these. I was going to go for the rocket rss300 adaptive-dipole design, but with the current sell, I could use a couple floor standers (Rocket 450's) for just $100 more, so trying to decide. Since my room has some reflections and I won't be wall mounting these, what would you recommend?

 

[jostenmeat]

I agree that jcPanny makes some very good points. Essentially the reasons I would not try di-poles with my present setup.

I remember something now... something Im sure you know already Soundman, but just in case. Some bi-pole type speakers, I think of PSB, can be switched from di-pole to bi-pole to even "double mono-pole"(!?!), meaning you can have side surrounds + rear surrounds coming from the same cabinet. These types of speakers are pretty expensive, but perhaps worth trying if you land a deal, or keep eyes peeled out on classifieds.

There is almost no going wrong (outside of over-spending). Because, you can try pretty much try every possibility with one cabinet and know for sure. Even if that means as a "single mono-pole", leaving the other side's driver(s) inactive.

However, if you are pretty sure its untamed reflections making surround sound difficult, I would also stay away from dipoles. Are your present speakers dipoles, or bipoles?

 

[Soundman]

I agree that jcPanny makes some very good points. Essentially the reasons I would not try di-poles with my present setup.

I remember something now... something Im sure you know already Soundman, but just in case. Some bi-pole type speakers, I think of PSB, can be switched from di-pole to bi-pole to even "double mono-pole"(!?!), meaning you can have side surrounds + rear surrounds coming from the same cabinet. These types of speakers are pretty expensive, but perhaps worth trying if you land a deal, or keep eyes peeled out on classifieds.

There is almost no going wrong (outside of over-spending). Because, you can try pretty much try every possibility with one cabinet and know for sure. Even if that means as a "single mono-pole", leaving the other side's driver(s) inactive.


However, if you are pretty sure its untamed reflections making surround sound difficult, I would also stay away from dipoles. Are your present speakers dipoles, or bipoles?

I was using th the Axiom QS8's as surrounds, but i sent the Axioms back due to brightness in my room. The rockets, being more laid back I thought might work better. At high volumes, when watching movies with the axioms, it seemed that everything sounded a bit congested. the detail was excellent, but the imaging was way off. i thought maybe the reflections had something to do with it.

 

[Joe Schmoe]

I have tried a lot of different surrounds, including monopoles and bipoles, and ranging from really cheap to equalling my mains. My conclusion is that it makes very little difference. As long as I am getting the directional cues, the system sounds good (after all, the mains produce most of the sound.)

 

[Soundman]

I have tried a lot of different surrounds, including monopoles and bipoles, and ranging from really cheap to equalling my mains. My conclusion is that it makes very little difference. As long as I am getting the directional cues, the system sounds good (after all, the mains produce most of the sound.)

thanks for the feedback. I'll keep in mind what you said. The main concern for me is that the sound does not become congested. This is what I experienced with the Axioms and my theory is b/c of the reflections in my room combined with the quad-pole design.

 

[jcPanny]

Surround Channels

Ideally, I would try to get the tweeters in the surround channels higher than ear level whether that means some 30" or higher stands for the bipole speaker or risers for the 450 floorstanders.

If you have the bipoles and don't like that effect, with a little soldering you could swap the wires on one of the tweeters and you would have a bipole type speaker with both firing in phase.

Also keep in mind that the performance of the mains and center channel are going to be effected by the reflections just as much or more than the surround channels.

 

[j_garcia]

I prefer monopole in almost all cases. The purpose of multipoles is to create a diffused sound, so they rely on those reflections. For a monopole, you want to use a similar strategy IMO, you still want to hear a reflection rahter than the direct sound, however it is still far more direct vs a multi-pole.

My speakers are all at ear level and it sounds wonderful; I wouldn't have it any other way for multichannel music. I personally feel that having the surrounds above you is a complete myth.

 

[Soundman]

I prefer monopole in almost all cases. The purpose of multipoles is to create a diffused sound, so they rely on those reflections. For a monopole, you want to use a similar strategy IMO, you still want to hear a reflection rahter than the direct sound, however it is still far more direct vs a multi-pole.

My speakers are all at ear level and it sounds wonderful; I wouldn't have it any other way for multichannel music. I personally feel that having the surrounds above you is a complete myth.

Thanks for the input J! I've decided to go with the Rockets. The deal is just too sweet right now! After doing some research, I've found that the rs450's are a much better speaker then the 300's(dipoles), or the rs250 bookshelfs, They have the same crossover and drivers as the main's and center channel in the rocket line so they should create a near seamless soundfield, and work well for a surround speaker. And with the sale, about the same price as the bookshelves, once you factor in the price of stands. I do have some stands but I can use them in another room anyway. I think the 450's on the risers should be right at the ideal height for a surround speaker. The off-axis response is suppose to be very good, due to the Vifa tweeter used in that speaker. Next step now is to try to treat that room. I guess I have some time to think on that since they won't be delivered until at least the end of December. But at least I got my pre-order in