My current experiment

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Saurav

My current experiment
« on: 14 Feb 2010, 04:56 pm »
I'm playing with the concept of narrow / minimalistic baffles and using the driver below the dipole peak.





Drivers are B&G Neo3PDRW, Audax PR170M0, AE OB12. XO is a DCX2496, LR4 @ 350Hz and 1800Hz. The dispersion is fairly even up to around 6kHz, after which the tweeter runs into diffraction problems with the sharp edge.

Gated FR, midrange straight vs. reversed:



Ungated FR, 1/3 octave smoothed, LR4 high-pass @ 80Hz, midrange straight and reversed:



Polars from the front (approximately 15 degrees each except for the last one):



And from the back. The XO needed some delay on the tweeter to phase-align with the midrange on the front, and I'll bet that's partly responsible for the 2kHz null in the back:



I just bought LspCAD, so next up is playing with the crossover, and trying to fix the edge problems on the Neo3 without increasing the effective baffle width too much. Here's one idea:





The sound is pretty enjoyable. I've had the midrange and woofer for a while now, and the dipole tweeter is a new addition. Previously I had a couple different CD tweeters on a couple different waveguides, and I could never get the treble soundstage to integrate well with the rest. Those problems seem to be gone now, and the treble region has taken on a depth and texture that I didn't have before.

Rudolf

Re: My current experiment
« Reply #1 on: 14 Feb 2010, 08:54 pm »
I've just put my recent idea about dipole tweeters on diyAudio: http://www.diyaudio.com/forums/multi-way/161299-directivity-dipole-tweeters.html
If anything, you want to cut material off the Neo3 :o and not add anything to it IMHO.

Saurav

Re: My current experiment
« Reply #2 on: 14 Feb 2010, 08:59 pm »
Well I know, but then I'd really need to cross to a smaller super-tweeter at around 4kHz, and then maybe another even smaller driver an octave up :) I figured at some point I have to start thinking about balancing dipole dispersion vs. the on-axis problems from diffraction.

DanTheMan

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Re: My current experiment
« Reply #3 on: 17 Feb 2010, 11:04 pm »
Nice project Saurav!  Looking forward to seeing more from it.

Dan

johnk...

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Re: My current experiment
« Reply #4 on: 12 Mar 2010, 11:41 pm »
I like the way you are using the NeO3. I used it that way in my "Bird Cage" speaker that I showed at the New England DIY  in 2008. I have a new system in the works. You may want to look at the polar plots I am getting. http://www.musicanddesign.com/NaO_Note_Previews.html

Saurav

Re: My current experiment
« Reply #5 on: 13 Mar 2010, 12:09 am »
I've seen that preview page, and I hope you release some information soon about how you're getting those results. Or maybe even a hint or two :)