Hopefully it becomes a moot point. It's not anything I came up with. There are whole companies around marketing speakers for home theatre or music systems.
Its still eq, but passiv you can only dampen. Boost can only be done in active systems. Im not sure what you mean by boost over 300 hz. I suggest a filter that will dampen by 6 dB from below 100 hz to 300 hz. This should give a fairly flat response. A filter that cut out only above 300 hz, will not compensate the 6 dB dipole loss, and the deep bass will be quite low compared to the upper bass. Unless you use very high Qt woofer you need to compensate.
What's a better (affordable) tweeter to put in there? The lens 1" bolt-on. Radian has some wonderful 3" diaphragm devices that play down to 800hz for around $200.
I was considering just cutting it and glueing a BG NEO3 ribbon (happen to have a lot of them) into the rectangularish throat of the horn. Anyone tried that?
I was considering just cutting it and glueing a BG NEO3 ribbon (happen to have a lot of them) into the rectangularish throat of the horn. Anyone tried that?
acoustic elegance and b&g 3 way dipole nobaffle passive xover
Hi to all,
here is my system, with ae 15" dipole woofer and neo 8 pdr / neo 3 pdr dipole mid tweeter :
if someone is interested I will post more detail, as well as measures and design consideration. the frame is made from water tube, not the best look, but very sturdy...
Hi to all,
here is my system, with ae 15" dipole woofer and neo 8 pdr / neo 3 pdr dipole mid tweeter :
if someone is interested I will post more detail, as well as measures and design consideration. the frame is made from water tube, not the best look, but very sturdy...
You need some inductors to experiment. I would start with even larger coil. 10 mH then measure. You should be able to get flat response from 40 Hz to 200 Hz. It also depends on baffle with and shape.
Please do post more details, like the crossover hz between the neo8 and woofer. Thanks!
Smart! Does the loosely hung mounting on the Neo8 cause additional distortion? Did you actually need the Neo3 (ie. does it add more than complicate)?
robixxx1, I'm interested in how the nude 15" really measures and behaves in a room, near the floor and walls... is it AE ?Dipole15 - Open Baffle Applications - Acoustic Elegance woofer
Here is Edge sim of it in free air. It takes 15 dB eq to 50Hz
Here is Edge sim of it in free air. It takes 15 dB eq to 50Hz
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The crossover between the AE 15" dipole woofer and the NEO8 PDR is 1KHz, not so low as one would expect, because the NEO 8 could also go down to 400HZ, but the issue is the totally lack of baffle for the NEO8, that cause the response to drop below about 1Khz. So to have about 80dB/w/1m, the NEO8 should operate from 1kHz and so the woofer has to extend up to about 2kHz or more, and that's because the AE 15" dipole was selected: it has a very good mid range up to 4Khz. The woofer directivity is not a problem, because it's a dipole system...
Why you think the loosely hung mounting on the Neo8 could cause additional distortion? I don't check this, but I don't think so...
The NEO3 is not mandatory, as the NEO8 can work up to 12-15kHz (with notch filter, otherwise the 12kHz peak in the response is very annoying ). I've added the NEO3 because the dispersion of the NEO8 at higher frequency is not so good, and the crossover complication needed to add the third way is not so much...
My goal was to made a baffleless dipole speaker, with an SPL of about 80dB/W/1m, a response from about 40-50Hz and passive xover.
To have a 90 dB at 3 meter in room, I use 400W / 4 Ohm Hypex class D amps, so the big problem is the power / excursion handling at low frequency: for that reason after having simulated a few 15" and 18" woofers, I've finally selected the AE 15" dipole, also for the very good mid range extension and low distorsion. To have intrinsic dipolar operation for mid / high driver, I've selected the B&G NEO8 / NEO 3.
The frame is made with steel water tube, because I am not able to do carpentry work... but in the future, since it works very well, I could build a beauifull plywood frame or have a carpenter make a nice metal frame.
More detail to come...
?
Well, because the nude Neo8 takes over at 1kHz, woofer directivity is not a problem. Yes I know Neo8 can't take much low boost-EQ - I cross it LR2/800Hz to 12" nude woofer.
My question was about bass (say below 200Hz) operation in a room. Dipole backwave is negative polarity, and how it's reflected backwave interferes with frontal wavefront depends on distance to front wall and wavelength. Backwave gets some 6dB boost from the wall as well, making summation and phase behaviour even trickier IRL.
My choice is to use monopole bass below 150Hz and to rotate dipole drivers roughly 40deg inwards. This seems to help a lot, verified by measurements of response and wavelet analysis, as well as by listening. Linkwitz says dipoles should have 2m distance to front wall, but that is not possible for me.
John Kreskowsky tells more about it here Boundary effects
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Yes the woofer is the AE Dipole 15-D8 (double 8Ohm coil that I use connected in parallel ). I've made some measurement with REW software in room, with the speaker on the floor and near the wall and the mic in my listen position (at a distance of 3m and at a height of 1m ): I post the left woofer (the one in the yesterday picture ) with and without the low pass filter (4mH + 47uF). I also post the Basta! simulation, where you can see how I've simulated the baffle to take into account the floor reflection...
I don't use 15 boost on the low frequency, I waste 15dB in the mid high...
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I have to try some "electronic eq" from 20 to 50Hz, by adding a simple passive filter before the final amp...
Very interesting the article you quote from John Kreskowsky, Boundary effects: I suppose that's why in your system you're gone with sp woofer below 150Hz, isnt'it?
Do you think that in my case the drop below 50Hz could be caused by backwall reflection? I have to take some measurement with the woofer at different distance from backwall to check...
Very interesting the article you quote from John Kreskowsky, Boundary effects: I suppose that's why in your system you're gone with sp woofer below 150Hz, isnt'it?
Do you think that in my case the drop below 50Hz could be caused by backwall reflection? I have to take some measurement with the woofer at different distance from backwall to check...
I will make the measurement , I'm courius to see if in my case the rear wall is responsible for the drop under 50Hz... In the meantime I've read your project, very interesting! And how you judge the sonic quality of the dsp? I prefer go passive because I've read some negative opinion about the sound of the dsp module but I've never heard one by myself...