New BG neo 10 planars

sonicboom · « **on:** 21 Oct 2005, 04:08 am »

Hi Danny,

Just noticed that BG is out with a neo 10 planar. Have you had a chance to hear and play with them so far? I am also wondering if there are any plans for you to carry this driver in your lineup and if you 're planing on using it in a furure project.

This is pretty exciting news given that these larger panels can play down to 150Hz

http://www.bgcorp.com/news.read.php?article_id=11

Cheers

Jon L · « **Reply #1 on:** 21 Oct 2005, 04:16 am »

# Significantly higher sensitivity- 93dB/1W/1m
# Extraordinary power handling and output- up to 120dB in R-800
# Lower operating frequency range- down to 150Hz
# Incredible linearity with lower distortion

I doubt it has true 150 Hz extension with high output, but the high sensitivity is really encouraging b/c you can connect two to get 96dB sensitivity. The Aurum Cantus ribbon tweeter can play in that sensitivity range, so add a couple of Focal Audiom type high-sensivity woofers, and we have 96dB sensitive speakers, perfect for high-quality, low-power amps.

Danny Richie · « **Reply #2 on:** 21 Oct 2005, 01:27 pm »

I have been following development on it for the past year.

This is not a driver that they will be releasing to any other companies but they have mentioned allowing me to use it in a new King Kong sized line source with Neo 3 pdr's along side them. The bottom end then being covered by six 12" woofers per side that are powered with their own amp. The Neo 10's may even be used in an open baffle.

For this I have asked for milled Aluminum chassis for the drivers instead of the stamped steel frames. They agreed but have many details to work out including CAD drawings of the frames.

It is going to take some time to get all of this in place, but we'll see where it goes and if everyone involved can make it happen.

And yes they will play down that low. The design of these allows for a lot of movement of the diaphragm. Think of it as a planar magnetic driver with a corrugated woofer suspension, and they have patented the technology.

JoshK · « **Reply #3 on:** 21 Oct 2005, 02:34 pm »

Jon, I don't think you will up the sensitivity to 96db by using two because of the dispersion characteristics of planars. The same rule of thumb for cones doesn't work with planars.

klh · « **Reply #4 on:** 21 Oct 2005, 03:57 pm »

Provided things fall into place, do you think you would offer that as a kit? I realise we are talking about something that will likely take at least a year if not two or three to be released, but it sounds like one hell of a speaker. Would the 12" subs also have an open baffle? Imagine a row of XBL subs lined up along rows of the 10" and 3" neo panels and all with one open baffle. That would be huge (literally)! It sounds fantastic, but I wonder if it's realistic since it would require such a large room.

Danny Richie · « **Reply #5 on:** 21 Oct 2005, 04:08 pm »

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Jon, I don't think you will up the sensitivity to 96db by using two because of the dispersion characteristics of planars. The same rule of thumb for cones doesn't work with planars.

Actually Josh, it is exactly the same. It make no difference what type of diaphragm it is. Any time a driver plays a wavelength that is shorter (length of the wavelength) than the diameter of the diaphragm then it will beam. As wavelengths approach the diameter length of the diaphragm it looses off axis response.

The Neo 10 will have a vertical dispersion equal to that of a 10" woofer and a horizontal dispersion equal to that of a 5" woofer.

Danny Richie · « **Reply #6 on:** 21 Oct 2005, 04:20 pm »

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Provided things fall into place, do you think you would offer that as a kit?

Not likely. The other companies involved in this would not go for it. BG specifically wants close control of this one too.

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Would the 12" subs also have an open baffle?

Not likely.

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Imagine a row of XBL subs lined up along rows of the 10" and 3" neo panels and all with one open baffle. That would be huge (literally)!

Yea and the acceptance factor of that would be pretty low.

Imagine a long row of Neo 10's and row of Neo 3 pdr's side by side in a baffle less than 12" wide. Behind that baffle by about 12" to 16" a separate enclosure housing six side firing 12" woofers, all in sealed enclosures and with their own amp and transform circuit keeping them flat to 20Hz.

Using that many of the Neo 10's might get the crossover point as low as 100Hz so blending them to the side firing 12's would not be a problem.

The customers amp would only be driving the pure resistive load of the Neo's and be very happy with it.

It will be a hell of a speaker only just now being made possible by this new technology.

Like mentioned before, it will take a while though, and it will be expensive.

JoshK · « **Reply #7 on:** 21 Oct 2005, 04:35 pm »

Well I don't want to get into a pissing match, but I disagree with you Danny and would point you to Dr. Griffins paper that would back me up.

klh · « **Reply #8 on:** 21 Oct 2005, 05:38 pm »

Good luck with the design and build out. Although it would be nice to have access to somthing like that, I can understand why BG would keep a tight grip on sales and distribution... it makes a lot of sense.

Danny Richie · « **Reply #9 on:** 21 Oct 2005, 05:53 pm »

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Well I don't want to get into a pissing match, but I disagree with you Danny

On what basis? Take this further and I'll teach you otherwise. No pissing required.

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and would point you to Dr. Griffins paper that would back me up.

I don't think so. Why don't you quote it for me, or show me.

JoshK · « **Reply #10 on:** 21 Oct 2005, 06:17 pm »

End of first paragraph, page 15 and supporting figure #10.

The paper can be obtained from http://www.audiodiycentral.com/awpapers.shtml

Pages 14-18 address this topic, but in very short simple terms in order to get the increased SPL the drivers must have overlapping radiation patterns, he also suggest that tweeters and planars do not have overlapping radiation patter (or at least very minimal).

ekovalsky · « **Reply #11 on:** 21 Oct 2005, 06:35 pm »

Quote from: Danny

Yea and the acceptance factor of that would be pretty low.

Sounds pretty sweet to me! There aren't many three way line arrays out there -- Swans 2.2, big Genesis, maybe the big Alons/Nolas if you consider the four woofers an expanded array configuration.

Build It, and They Will Come

ekovalsky · « **Reply #12 on:** 21 Oct 2005, 06:54 pm »

Quote from: JoshK

End of first paragraph, page 15 and supporting figure #10.

The paper can be obtained from http://www.audiodiycentral.com/awpapers.shtml

Pages 14-18 address this topic, but in very short simple terms in order to get the increased SPL the drivers must have overlapping radiation patterns, he also suggest that tweeters and planars do not have overlapping radiation patter (or at least very minimal).

Josh, I think it may depend on the frequency. In an array, there would probably be summation of output at lower and middle frequencies, with less summation at higher frequencies. If this driver were to be crossed over to a tweeter, doubling the number of drivers should add 3dB sensitivity over the operating range.

Unlike the Sonigistix planar, this driver should be able to go low (150-200hz) with impact -- because of the rigid drive element and suspension, the whole surface and not just the center should be able to move in a pistonic manner. This is totally new technology for planar drivers, hence the patent. And it probably won't be used in a two way array like the Alpha, rather it will be crossed to tweeters which will be better performers above 3khz or so.

OK, what I want is an open baffle main channel with line arrays of small XBL^2 woofers, neo 10 planars, and true ribbon tweeters. Each driver group to be connected to its own set of binding posts, for use with either external passive crossover box a la Danny, or optional DEQX or similar. Then a separate sub-bass tower with four to six 12" ported or vented subwoofers per side operating below 40hz. Come on Danny, it's time to take on and bitch slap the Genesis 1.1 and Martin Logan Statement E2 and Alon Grand Reference

Danny Richie · « **Reply #13 on:** 21 Oct 2005, 08:05 pm »

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Pages 14-18 address this topic, but in very short simple terms in order to get the increased SPL the drivers must have overlapping radiation patterns

Certainly, and they do. Whether they are planar magnetic, ribbons, or woofers, it is all the same.

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he also suggest that tweeters and planars do not have overlapping radiation patter (or at least very minimal).

Yes and no. But in general the statement is false as all exhibit added gain from combining output. In other words they all overlap one another in the ranges they cover depending on frequency. It is all frequency dependent.

I have designed and measured many line source designs and have witnessed it every time.

Take this one that I designed.

The planar magnetics cross over to the woofers in the 1,200Hz range. By that point they have created about 12 to 15db or so of gain that must be attenuated with the crossover. At those frequency ranges sound is transmitted in all directions pretty evenly from each driver, so there is a lot of added gain.

Now those Neo 3's are 2 and a 1/8 inches tall by the playing surface. So frequency ranges above 6500Hz begins to behave just as Jim Griffin illustrated in his chart on page 15.

If the Neo's were to be 2.125" woofers it would behave exactly the same.

This is why using a single Neo 3 as a tweeter works very well and has pretty good vertical dispersion.

By contrast a longer ribbon in the 6" length range would be in its beaming frequency by 2.3kHz. A woofer of the same size will do the same. Frequency ranges below this point will extend beyond the length of the diaphragm.

It is not a brick wall effect either. It is a slow progression with about a first order roll off rate.

Danny Richie · « **Reply #14 on:** 21 Oct 2005, 08:15 pm »

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OK, what I want is an open baffle main channel with line arrays of small XBL^2 woofers, neo 10 planars, and true ribbon tweeters...

Okay how about an array of 6.5" woofers with XBL^ motors, designed to be used in free air (high Q compliance) in an open baffle with a new Neo 3 sized planar magnetic array along side it. Then the the tower of six 12" woofers right behind it made to look like one box with the open air area covered with grill cloth like the Alon's...

And affordable.

Already on the drawing board.

arthurs · « **Reply #15 on:** 21 Oct 2005, 08:30 pm »

what's the speaker in the pic Danny?

Danny Richie · « **Reply #16 on:** 21 Oct 2005, 08:38 pm »

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what's the speaker in the pic Danny?

It's a personal pair of Epiphany 20/21's that I own.

JoshK · « **Reply #17 on:** 21 Oct 2005, 08:50 pm »

I understand the way this works more than you think Danny. But going back to the original topic at hand, if your using a line array of this 10" neopanal and you were to keep the drivers spaced tightly together so that no combing issues were introduced on the top end of the bandpass you would not be getting SPL gain. Atleast for all but maybe the lowest midbass frequencies, even then it is still questionable.

I re-read Jon L's post and I see now that he mentioned a sort of MTM arrangement, I didn't catch that when I skimmed it quickly the first time. There the issue is a bit trickier because you want to avoid comb filtering up top so you'd want to keep them closer together, so you would get no gain in the top portion of the bandpass but the line isn't long enough so you would get gain the lower portion. This is a bad design decision in my opinion.

ekovalsky · « **Reply #18 on:** 21 Oct 2005, 09:22 pm »

Quote from: Danny

Okay how about an array of 6.5" woofers with XBL^ motors, designed to be used in free air (high Q compliance) in an open baffle with a new Neo 3 sized planar magnetic array along side it. Then the the tower of six 12" woofers right behind it made to look like one box with the open air area covered with grill cloth like the Alon's...

And affordable.

Already on the drawing board.

Well that sounds intriguing. While I love my current speakers, if I can get equivalent or better performance in furniture quality cabinets with good quality control for a reasonable price, of course I'm interested.

So would open baffle arrays skip the Neo10s, being a two way system with the XBL woofers and a new small planar magnetic driver ?

I know you've played with most if not all the ribbon tweeters on the market. Curious why you prefer the planar magnetics to them, other than their ability to cross lower ?

In the past I was really gung ho on digital crossovers. But based on my experiments with multi-amping with digital amps and DSP crossovers versus using a single high quality analog amp (in my case a Blue Circle BC204 hybrid) with the passive crossver, the latter setup won easily. Still, I like the system Alon uses -- direct connection of driver groups to the binding posts with an external passive crossover box that can be bypassed in the future. I have also found that putting the crossover box on an isolation platform improves the sound. In fact this is in fact part of the revIII upgrade that Carl M. is offering for my speakers, along with some tweaks to the crossover itself.

Danny Richie · « **Reply #19 on:** 21 Oct 2005, 10:17 pm »

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if your using a line array of this 10" neopanal and you were to keep the drivers spaced tightly together so that no combing issues were introduced on the top end of the bandpass you would not be getting SPL gain.

Actually quite the opposite again. You will get gain over the entire range that they would cover.

The opening of the diaphragm is about 9" long on the Neo 10 (vertically). This means that it will have good off axis response, without getting into a beaming area, to about 1,500Hz.

Below this range they will be coupling and providing quite a bit of gain. Above this range they will begin to beam and no significant gain will be had above that range.

No problem there as the crossover point would be below that range.

No comb filtering effect would be present either as it will not play high enough in frequency to have any comb filtering effect. With the surface of the drivers being only 1" or so apart there can be no comb filtering between adjacent drivers until after 14khz. They will never play that high.

Quote

I re-read Jon L's post and I see now that he mentioned a sort of MTM arrangement, I didn't catch that when I skimmed it quickly the first time. There the issue is a bit trickier because you want to avoid comb filtering up top so you'd want to keep them closer together, so you would get no gain in the top portion of the bandpass but the line isn't long enough so you would get gain the lower portion. This is a bad design decision in my opinion.

Actually it is once again exactly the same as using a pair of 10" woofers in an MTM design. All you need is a tweeter capable of being crossed in the 1kHz to 1,200Hz range and it would not be a problem. There would be no comb filtering effects of the Neo 10's and they would couple together and play as one unit.