monopole/dipole ribbon/planar mix?

[MarzZ]

Before I start a prototype project I would like some of your thoughts.

My goal is to get the awesome speed, accuracy, and deep sound stage of a monopole ribbon like using Newform's ribbon for the high-end, merge that with a line source planar (possibly dipole) to keep the line source format and gain from not using an array of 8" woofers which could cause comb filter interference and mid bass woofer(s) (10"-12"'s) in a sealed box( or dipole?). I have the lower and infrasonics covered already with a sealed 18" sub I am very happy with.

Basically I'd like to gain the advantages of the speed and accuracy of ribbons/planars and augment it with really fast/ higher spl mid bass.

Line source, monopole ribbons for frequencies approximately <8khz and up

Line source, dipole planar for <300hz to around 8khz




RP <---line source ribbon tweeter with planar right next to it, keeping a slim baffle size.
RP
RP
W <--- singe or dual 10" mid bass woofer(s), sealed or dipole?

I've listened to a few planars and to me they don't resolve the upper frequencies as well as the ribbons do IMO. I really like what planars do for the midrange (3D, lifelike), and being a bass player I love good punchy mid bass which I think can only come from 10"s in a sealed/ported box. But I am curious of dipole bass, like what Legacy did with their Whisper or Linkwitz's dipole sub.

What kind of problems would there be if you had monopole high frequencies with dipole mids and monopole/dipole mid bass mixed?

Would the system be more accurate and keep the depth of sound stage if all drivers remained monopole and sealed? This would make things more simple, But I wouldn't mind experimenting with some dipole application if it wasn't too complicated for me.

I intend to use active crossovers.

TIA!

[Telstar]

the first advice that i can give you is to absolutely cover the midbass with dipole (down at least to 100hz), which means 2x 12" or 1-2 15".

[craigj]

MarzZ,

I'll give you the same excellent advice you gave Fiat79, if you haven't already, call and have a chat with John Meyer of NFR. John is easily approachable and is always eager to assist the diy/Newform speaker crowd.

That being said, I don't believe John is a big fan of dipole. You may of already seen that Newform experimented with mating the R45 and a planer, yet didn't continue with the design.

What drivers do you have, what is your budget, and how big is your room? Finally, here is a link to a current planer project: HTGuide Forum - New Home for the BG Ribbons - Part 27 scroll down to post 413 for pic.

Cj

[MarzZ]

Originally Posted by craigj

MarzZ,

I'll give you the same excellent advice you gave Fiat79, if you haven't already, call and have a chat with John Meyer of NFR. John is easily approachable and is always eager to assist the diy/Newform speaker crowd.

That being said, I don't believe John is a big fan of dipole. You may of already seen that Newform experimented with mating the R45 and a planer, yet didn't continue with the design.

What drivers do you have, what is your budget, and how big is your room? Finally, here is a link to a current planer project: HTGuide Forum - New Home for the BG Ribbons - Part 27 scroll down to post 413 for pic.

Cj

Thanks for your reply. Yes I have talked to John Meyer on a couple of occasions, but he did not respond to my DIY questions and I'm fine with that. I respect that he has a company to run.

Where can I find the information about the R45/planar experiment? What was the outcome?

Dipole pros and cons for the high-mid-low frequencies are my main questions. Given that high to mid frequencies are more easily localized wouldn't it make sense to keep those frequencies in a monopole configuration to avoid room interactions? I know that many dipole/bipole fans consider this the main benefit.

So, if I go monopole for some of the frequencies I have to pay attention to the sound stage by mixing in dipole drivers, correct?

I am interested in the "no box" solution, but only if i can correctly integrate all drivers to give a decently accurate sound stage. I guess I can try the dipole configuration first and later enclose them if I don't like the results.

I am open to most drivers, but I am very interested in Newform's ribbons for the upper frequencies.

I have available some ATC 26" planars. They are dipole by nature and are good in between the range of 250hz to about 5k. I still have to measure. They do have restricted vertical dispersion, just like the Newform ribbon. I believe this would be beneficial as this allows me NOT to have multiple conventional mid range drivers that would cause comb filtering and interact more with the floor and ceiling as well as cost more.

As for the low to high mids (40hz to 300 500hz) I am thinking (2) 12-15" speakers if they are to be dipole, or a single 12-15" in a sealed enclosure.

[MarzZ]

Here's my room layout and dimensions.

I'd like to be able to get 100+ SPL from 20hz to 20khz at the listening position.

[craigj]

Good morning MarzZ,

Thanks for the room info. What drivers do you currently have, is there a waf involved, size, & look of speaker for you, and what is your budget? Coffee is brewing, so I'll do some searching to try and answer some of your current questions.

Cj

p.s. what did you think of the Boehlender Graebener project at HTGuide?

[craigj]

Here is a link to Newforms R45 & electrostat prototype combo: INTERESTING PROTOTYPES - New Technology Ribbon Loudspeakers for Superb Home Theater and HiFi Stereo. Ribbon speakers for high end audio.

[MarzZ]

Originally Posted by craigj

Good morning MarzZ,

Thanks for the room info. What drivers do you currently have, is there a waf involved, size, & look of speaker for you, and what is your budget? Coffee is brewing, so I'll do some searching to try and answer some of your current questions.

Cj

p.s. what did you think of the Boehlender Graebener project at HTGuide?

I haven't pulled the trigger on the drivers yet, but i have several standing by when I'm ready. No WAF involved, just a loving GF that let's me do as I please. Although, I don't want huge baffles like on some projects I have seen here. I figure about around 2g's for budget.

I like the BG's. I was thinking of trying those for a while. I did some research but I have not heard them in person yet. I have heard a few Martin Logans and they sounded great in the midrange. I think BG owns or co- develops ML's. The ML's don't resolve the highs as well as the newforms IMO. I think it's just a matter of basic physics, i may be wrong, but a lighter, lower mass, element is going to react faster and stop faster, so a ribbon should win that department, no? If cost was no object I would love to try to mate some newforms with some ML CLS'. Add to that 2 15's for dipole bass-mid bass. I'll save that for a later project.

What I'm really going after is the big Main Monitor sound of Genelecs, with the resolution and ability of ribbon drivers and planars. Most speaker IMO lack big punchy mid bass. Maybe I'm reaching to far, because I am not sure that dipole bass, ribbon, and planars will be able to handle the higher SPL's without distortion. However, my SPL goal is modest I believe..around 105-107db. I want to save my ears all I can.

I

[MarzZ]

Originally Posted by craigj

Here is a link to Newforms R45 & electrostat prototype combo: INTERESTING PROTOTYPES - New Technology Ribbon Loudspeakers for Superb Home Theater and HiFi Stereo. Ribbon speakers for high end audio.

That looks interesting. I will have to try to call John M for the details of that prototype and its sound characteristics of mixing the dipole with a monopole.

[a.wayne]

Originally Posted by MarzZ

Here's my room layout and dimensions.

I'd like to be able to get 100+ SPL from 20hz to 20khz at the listening position.

Hello ,

1. Very unlikely you will get a 20 hz note in such a small room . Figure on pulling the dipoles @ least 4 ft into the room for proper sound reducing your listening position by such .

2. The dipole radiator , is going to need a dipole tweeter to sound right and have proper acoustic phase . If not , I'm betting the speaker will end up being very incoherent .

3. I found both the Boehlander and the NF to be very efficient , but aggressive and hard sounding drivers.

4. To reach your desired goal , i would use the BL , it is capable of driving big time and will make good SPL ..

regards,