NaO Note preview

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The picture:

An externally hosted image should be here but it was not working when we last tested it.


I was anticipating something more revolutionary actually as this approach is "well known".

Also in the Dipole sphere, SL has revised the EQ for his Orion which "lifted the veil". I'm not sure I like that overused description but it is a new speaker after the changes:

ORION-3
 
Sorry you are disappointed. :) However, it is more important to do it right than to do it differently. Certainly the basic baffle format is dictated by the physics of the dipole problem, but it is attention to details that make or break a design. Crossover points must be chosen correctly; there is also a shallow, symmetric wave guide on the tweeter; and the basic panel is designed as a 3.5 way with the lower midwoofer providing the required extra cone area below 400 Hz.

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?:forbiddn:) 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.
 
Sorry you are disappointed. :) However, it is more important to do it right than to do it differently. Certainly the basic baffle format is dictated by the physics of the dipole problem, but it is attention to details that make or break a design. Crossover points must be chosen correctly; there is also a shallow, symmetric wave guide on the tweeter; and the basic panel is designed as a 3.5 way with the lower midwoofer providing the required extra cone area below 400 Hz.
John, was there much difficulty with offsets between the upper midwoofer and the small and I assume much shallower midrange? As a dipole I know that you've addressed the issue related to corrections for offset on the front vs. corresponding and possibly detrimental impact to the rear output. Was the fact that you used a midwoofer rather than a larger true woofer in this range a benefit in this regard or did it all end up not being much of an impact?

Dave
 
John, was there much difficulty with offsets between the upper midwoofer and the small and I assume much shallower midrange? As a dipole I know that you've addressed the issue related to corrections for offset on the front vs. corresponding and possibly detrimental impact to the rear output. Was the fact that you used a midwoofer rather than a larger true woofer in this range a benefit in this regard or did it all end up not being much of an impact?

Dave

Well I guess the best way to address that is to post the rear response compared to the front. I have updated my Note Preview web page with that information. My focus was always on the front on axis and front hemisphere polar response so I am pleased with what the rear response is. I have seen a lot of highly regarded speakers which measure worse from the front than the Note does from the rear. :)

As we were discussing over at PE, it is certainly possible to make a symmetric dipole speaker by pairing front and rear firring drivers, but the down side is the required driver separation and the poor off axis response (i.e. blooming of the on axis response). Remember my little Bird House speaker that followed that approach at your DIY event two years ago.


John,

From your website, the x-over network shows only 1 tweeter, did you use one or two tweeters, ie one front and the other facing the rear?

The tweeter is the Neo 3 planar without rear cup. Thus one rear tweeter operating in dipole mode.
 
The picture:

NaO_Note-256x600.jpg


...
What's that behind it?
 
What's that behind it?

That is something I call the NaO DW. DW standing for Dayton Wright. I always love the DW ESL but I had to sell mine because they were too big for my room when I moved. The NaO DW is has 2 12" woofer and 2 10" woofer running in parallel/series. An 8" mid (SS 8554) and front and rear dome tweeters. It's a work in progress. Sort of a part bin speaker. I had the drivers lying around, unused, so I build what you see. Originally it was a wide, flat baffle but as I have said wide baffles don't work well for the midrange (Sometimes I don't even listen to myself ;)) so I have narrowed the baffle to about 12" for the mids. Big baffle for the woofers, narrowing down for the mid. It needs a lot of work. It is designed solely based on the DW aesthetics.

so you are using 2 tweeters but the x-over network shows only one, a mistake?

No. As Saurav said there is one Neo 3 tweeter. It is a planar tweeter that radiates fronr and rear when the rear cup is removed.

Nice work John! I bet they sound great! Does the rear of the tweeter have any sort of waveguide? I think I read elsewhere that the upper mid to tweeter XO is 6kHz? What about between the upper and lower mids?

The WG on the tweeter is symmetric, front and rear. X-O point are 120, 1k and about 6k. Tthe bottom mid starts to roll off about at about 500 Hz. (If I indicated differently before I was thinking of a different version of the x-o.) I really hate calling the thing on the tweeter a WG, but I guess that is what it is. It certainly makes a big difference in the polar response arond the x-o point. Without it things don't look so good.
 
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