Yes, you have them labeled correctly.
Agreed. However, my main concern is to maintain uniformity of the response to as wide an angle as possible. If you look at the data you will see that up to 4 k that is obtained over at least to 45 degrees off axis with a narrowing of the radiation pattern above that. The second thing I wanted was to assure that there was no blooming of the response off axis. That is, at any frequency the response off axis should never exceed the on axis response and the response should decrease in amplitude monotonically as the off axis angle increases (within praticle limits). This has been a problem in other designs where the midrange is crossover directly to a tweeter. I think I have also accomplished that up to the point where the Neo 3 begins to beam (above 10 k Hz). I don't think that a constantly deep null is that importance compared to the monotonic decrease as you move off axis. A -10 dB null is down to 0.1 power density compared to on axis. Also, a little shift in the mic position can make a bigh difference here. The null can shift forward or back a few degrees just by a little change in the delay and a slight differnce in level between front and rear can make the null seem shallow.
I think beaming is a little strong. The polar response starts to narrow but it is still decreasing monotonically as you move off axis. I think of beaming more in terms of what you describe as lobing. I.E. lack of monotonic behavior as you move off axis. I think you also have to be careful with regard to what might appear as lobing in the 7 to 8 k region. Is that truly a lobe at 90 or is it just a shift in the dipole null slightly forward? I really don't know but what appears to be a slight resurgence at 90 degrees is still way down.
Again, that depends on how you interpret the behavior around 7K.
No. If you look at the polar response plots and tried to have flat response at 30 degrees then this would require a rising response on axis. The other point I would make is that I don't know how designing for 30 flat degrees off axis would change the polar response. They are separate issues. One is a function of baffle size/shape and driver/WG directional characteristics and the other is just a function of at what angle you choose to eq the system to flat response. I could certainly eq my system for flat response at 30 degrees but it would have no effect on the polar response at all.
The last point I would make is that a naked Neo 3 has some real problems. That is why I put it in a WG. The WG causes some other problems but I feel they are less important.
I appreciate you comments and agree that the Note is not perfect. But it does represent a significant improvement over other dipole/OB system I have seen, including my own previous designs.
I have that and will post it soon. I also have such data for unfilters ERE 18, 10F and Neo 3. All to come.
You can solve the beaming of your tweeter by simpy instaling a vertical piece of paper or somehing, say as long as the tweeter and protruding some cm´s out. That trick was used for example on the very expensive Technics T1000 ribbon of yesterjor. In that case it was a little bit shaped to avoid discontiniuties.
I didn't recognize Saurav's mid either.
Mac: are you intending to come across as acrimonious? I'm not saying that your tone is such that your posts are entirely inappropriate, but it would be nice if you were a little less belligerent in this thread. They [your posts in this thread] certainly make John seem to be the more cool headed and reasonable one.
Any speaker design, even unpublished, is pretty much fair game for other individuals and/or companies to use as they see fit - whether to copy, or as a platform upon which to build sales of their own speaker, be it similar*, or distinctly dissimilar.
If someone was to copy my design, and then release it as a product even before I was able to release and sell mine (if that was my intention), then I think that has gone too far - though I don't know if there is any legal protection against that sort of corporate espionage? That's the point at which I could concede to calling it straight out "theft" rather than "using what others have learned" / "standing on the shoulders of giants". (using my design before I release it myself, makes it seem as though I am not the original, which I find particularly offensive, I am not referring to a particular instance here)
*If one was to copy another's existing speaker design either exactly, or almost exactly, I think there could be some kind of artistic copyright violation - but as to copying a design concept, or a particular crossover - there's no legal protection there unless patented.
Anyway, this new Nao Note is certainly interesting. I had bought a pair of those mids before learning of it, and, as many others, have been considering for a long time, such use of the Neo3 PDR - I may very well use that combination in some speakers of my own soon. But, my midwoofer (and posibly woofers, in a BR enclosure) will more likely be something I already have such as the Peerless HDS Nomex 6.5" model 830875.
Mac: are you intending to come across as acrimonious? I'm not saying that your tone is such that your posts are entirely inappropriate, but it would be nice if you were a little less belligerent in this thread. They [your posts in this thread] certainly make John seem to be the more cool headed and reasonable one.
Any speaker design, even unpublished, is pretty much fair game for other individuals and/or companies to use as they see fit - whether to copy, or as a platform upon which to build sales of their own speaker, be it similar*, or distinctly dissimilar.
If someone was to copy my design, and then release it as a product even before I was able to release and sell mine (if that was my intention), then I think that has gone too far - though I don't know if there is any legal protection against that sort of corporate espionage? That's the point at which I could concede to calling it straight out "theft" rather than "using what others have learned" / "standing on the shoulders of giants". (using my design before I release it myself, makes it seem as though I am not the original, which I find particularly offensive, I am not referring to a particular instance here)
*If one was to copy another's existing speaker design either exactly, or almost exactly, I think there could be some kind of artistic copyright violation - but as to copying a design concept, or a particular crossover - there's no legal protection there unless patented.
Anyway, this new Nao Note is certainly interesting. I had bought a pair of those mids before learning of it, and, as many others, have been considering for a long time, such use of the Neo3 PDR - I may very well use that combination in some speakers of my own soon. But, my midwoofer (and posibly woofers, in a BR enclosure) will more likely be something I already have such as the Peerless HDS Nomex 6.5" model 830875.
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You can also do this by limiting the horizontal sd -i.e. blocking/taping off several vertical rows of the Neo 3 (to the extreme right and left). I think Burmester does this in one of their designs. This one:
Burmester Audiosysteme GmbH ::: Products
http://hifi-regensburg.de/upload/CY62ab4e0aX125bd26d061XY4324/1261604468506/B_80.jpg
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That's what the Neo3 PDR is. There are strips of felt/foam in the outer slits which improves top end dispersion compared to the non-PDR version. There are photos somewhere on this forum that show this. I'm assuming the felt is chosen so the lower frequencies go through, thus the radiating area narrows as you go into the top of the tweeter range.
I played around with both the Neo 3 and Neo 3 PDR. I even looked at using two Neo 3 back to back (with back cups) so I could control the separation. The problems are at both low and high frequency. At high frequency there is some beaming (or lobing) of the response which is typical of a planar radiator. Blocking off some of the radiating area would help this but also reduces sensitivity. The other problem is that at lower frequencies the tweeter is not particularly directional. This places a dip in the response around 6k Hz, with the dipole peak around 3k, as shown here with a naked Neo3 PDR in blue. The wave guide controls the directivity and the dip is eliminated, as shown in red:
The problem with the naked Neo 3 is that as you move off axis the dipole moment gets shorter and pushes the peak higher. This make the response bloom relative to the on axis response as shown here in the "waterfall" of the polar response, normalized by the on axis response:
The trade off is that at higher frequency tweeter also becomes a little more directional. I imagine that with more work and testing a more optimum WG could be designed, but I am pretty happy with the behavior of the polar response out to 10K plus, combined with the smoothness of the on axis response that the wave guide provides.
An externally hosted image should be here but it was not working when we last tested it.
The problem with the naked Neo 3 is that as you move off axis the dipole moment gets shorter and pushes the peak higher. This make the response bloom relative to the on axis response as shown here in the "waterfall" of the polar response, normalized by the on axis response:
An externally hosted image should be here but it was not working when we last tested it.
The trade off is that at higher frequency tweeter also becomes a little more directional. I imagine that with more work and testing a more optimum WG could be designed, but I am pretty happy with the behavior of the polar response out to 10K plus, combined with the smoothness of the on axis response that the wave guide provides.
This are progressing. I have been listening for the last couple of weeks. Making some final adjustments. Still working on documentation. added a burst response plot taken with Arta to my web page:
An externally hosted image should be here but it was not working when we last tested it.
It looks pretty good. I'm please overall.
I have a lot on my table right now. Fires to put out. The speaker will be at the DIY NE. I may have to delay launch until just after than because I have other obligations which must also be completed by then.
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What can I say. I work with the tools that I have.
Your software cannot do overlaid frequency responses? Download REW for free. It can do 18 of them I believe.
Dan
I am glad to see that SL is not sitting on his laurels. When I build the Orion it was disturbingly obvious (to me) that the NaO II was significantly more natural sounding through the midrange, and I stated so at the time. (Of course who ever listened to me regarding the Orion?) Not that the Orion wasn't a good speaker at the time, but there was clearly room for improvement. This improvement has come slowly with the addition of the rear tweeter, subwoofers and now further modification to the eq.
In any event, the Note will be another option to those who wish to build a hybrid dipole speaker system.
I listen to my Summas for about eight to twelve hours a day, and occasionally I'll arrange them as a dipole. (One Summa facing forward, the other facing back, in the middle of the room.)
It's surprising how different this sounds; you'd think the extra energy radiated backwards would make a subtle difference.
But it's NOT subtle; the in-room sound is noticeably different.
I really enjoy the effect.
I DON'T enjoy moving 300lbs of loudspeaker though
I guess you concern is or was that the NaO II truly does out perform the Orion. The fact is that after hearing the Orion beside the NaO II not everyone walked aways with a NaO II plan set in hand. The coin has two sides, mac. It never concerned me that someone might choose the Orion over the NaO II. In fact, I know of at least one individual who made the effort to travel to an NaO owners home th hear them, then traveled to an Orion owners home to listen to them and finally ended up with a pair of Geddes speakers after auditioning them. Yuck!
It's all good!
That "Yuck!" was me. After e-mailing John K about his NaO II design I went to an owner of the NaO II in Pennsylvania and auditioned them on two separate occasions. I then auditioned the Orion's within about 3 months as well as the Pluto's in their latest iterations along with subwoofers (for both designs) directly at Sigfried's place, set up by SL himself. The NaO's were better and cheaper. In particular the midrange was cleaner sounding so John isn't just blowing smoke here. If somebody really wanted the Orions, I would ask them to audition the NaO's first or even GR Research's Super V's. My final encounter several months later was with Earl Geddes where I listened to his Summas on the worst electronics known to man and was completely blown away. I now own Abbeys but with John's U-frame subwoofers.
I hate to say this but you Orion enthusiasts are like flys on you know what. It's downright annoying. On its own its a good speaker. Factor in cost, and it becomes an overpriced speaker. And please don't compare yourselves to mega speakers from Dali, Von Schweikert, MBL, Legacy, etc...the designs I am speaking of are of much higher pedigree, in other words the competition is more fierce. The fellas that purchase $50K plus speakers could give a hoot about Earl Geddes, John K or SL. I could, but I am a diy'er and so I'm *informed* so to speak.
Sorry, but the Orions have been dethroned...
Anand.
I can't recall ever having seen a polar response as smooth as that. Looking forward to hearing them.
dlr
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