I run a 2426 bare naked on top of 2226 in BR @ 1.2k & prefer it by far over any horn or cd I have tried yet. Very realistic without any hint of Horn........... I am @ 9' for listening position & only one seat. Imaging is pin point. All ran with 45 SET useing stock SR4725 passive XO, albiet going full active as experiment.
Joe
Joe
Hi Joe,
What type of angle are you listening to your CD without horn, on or off axis?
Do you detect a problem with beaming in this configuration? If so, how do you deal with it.
And finally, at what listening volume to you run these drivers? I can only assume your using a 45 SET, that you are NOT driving very hard, or playing at rock concert levels.
Some claim the JBL 2226H to be hard to wake up with just a few watts?
Thanks
NW
What type of angle are you listening to your CD without horn, on or off axis?
Do you detect a problem with beaming in this configuration? If so, how do you deal with it.
And finally, at what listening volume to you run these drivers? I can only assume your using a 45 SET, that you are NOT driving very hard, or playing at rock concert levels.
Some claim the JBL 2226H to be hard to wake up with just a few watts?
Thanks
NW
I am running on axis, pointed directed at the listening position. I perceive no beaming. I run the 45 wide open & it does rock my 20x20x10 lid room @ I suppose 100+ db. I will be hooking my new 8w SE amp up to it soon & bi-amping either BBE ds48 or the Behringer digital unit. MY new SE I built has slight feedback in slightly shade circuit useing 807 outputs, 45 for 2426. So basically they are not just bieng tickled I would think & crystal clear. What is noticeable is the pin point imaging & absolute lack of a hint of horn or CD. The 2226 I find is a great driver IMO.
Joe
Joe
I'd imagine the 'exit termination' would be too abrupt on a naked compression driver.
Maybe some foam pads (or similar things) would help a little.
And it's really amazing it can sing down to 1.2kHz without 'proper' load !!
It's said someone runs the compression driver with the rear cap removed and aims the dome towards the listener. Should be interesting (and dipole!), but I never heard myself...
Maybe some foam pads (or similar things) would help a little.
And it's really amazing it can sing down to 1.2kHz without 'proper' load !!
It's said someone runs the compression driver with the rear cap removed and aims the dome towards the listener. Should be interesting (and dipole!), but I never heard myself...
I think the old westlake used nude 2426H for tweets and relied on the diffraction caused by this abrupt termination to widen the directivity (albeit only for UHF...)
concerning the rear faced compression driver, this is quite close to your idea:
1989 XPL SERIES
Yes, I was refering to the 1" long threaded nipple. Hey you got SR4725 parts..? why don't you give the above a try..? You might like it.
Joe
OT, Badman, but I'm about to get a DSP xo, looking at the usual Behringer or BBE DS48, the reason for looking at the ds48 is that supposedly it is quiet & sounds good out of box, Which would you grab..?
Joe
Joe
OT, Badman, but I'm about to get a DSP xo, looking at the usual Behringer or BBE DS48, the reason for looking at the ds48 is that supposedly it is quiet & sounds good out of box, Which would you grab..?
Joe
Im playing with the idea of making a large shallow waveguide made of MDF, say... 20 inches diameter, using the Radian 850PB crossed at 500hz. I highly doubt the waveguide will load down to 500hz, but it will at least give the compression driver a smooth mouth termination and some directivity controll.
Any thoughts?
Any thoughts?
The larger directivity you use, the more throat diffraction and room interaction.
I couldn't say which DSP unit I'd get. I have a marchand, which suffices for my work, as I am ultimately interested in maintaining a passive crossover when possible, despite all its evils.
The hornless driver...... thanks but there's enough problems with that that I can leave that on the table. If I want a 1" point source I'll use a dome.
So you say that it may be better to make the waveguide deeper and with a more narrow directivity? Ive thought about 18 inches wide, and 6 inches deep, with a roundover at the mouth. Will this be too shallow?
I like the idea of a wide-directivity waveguide. I don't want to argue it here, but there is a strong case for sidewall reflections bringing a positive contribution to the listening experience, provided they have a spectral balance matching the direct sound. So a wide, shallow, constant-directivity waveguide might be optimal in many rooms.
Downsides:
As you have noted, you'll likely give up some low end. Also, if you choose a 2" throat driver like the 850PB to feed such a wide-projecting waveguide, you'll get collapsing directivity beginning at maybe 4khz. The point of the waveguide will be largely moot above that, and it would be time to add a wide-dispersion (read narrow throat) tweeter above that.
Downsides:
As you have noted, you'll likely give up some low end. Also, if you choose a 2" throat driver like the 850PB to feed such a wide-projecting waveguide, you'll get collapsing directivity beginning at maybe 4khz. The point of the waveguide will be largely moot above that, and it would be time to add a wide-dispersion (read narrow throat) tweeter above that.
Great feedback
I will integrate a B&C DE10 at the top of the waveguide with a little wide dispersion spherical horn of its own all in one solid mdf waveguide. Im also thinking about using a small high eff direct radiator instead of the 850PB. Something like the 18sound 6ND410. Or maybe a dome midrange. Many possibilities
Its important though that I can use a simple 1st order filter between the two.
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Dome midranges usually have not-so-smooth directivity characters higher up. This is because the driving force (voice coil) spreads around the outer edge of the diaphragm and the breakups begin at the central area, which makes the effective emitting area (or its overall size) stays as large as the voice coil, and this is a bad thing for dispersion of higher frequencies. The shape of the dome is misleading. The wavefront would barely maintain that hemisphere shape, especially at higher frequencies.
OTOH, a cone driver has a shrinking effective emitting area as the frequency goes up because the breakups happen around the outer areas first. Inner areas of the cone follow the voice coil relatively more tightly thus play higher. The smaller effective emitting area higher up makes a cone driver have a smoother beaming.
Quite the opposite of the direct intuition by just seeing their physical shapes.
OTOH, a cone driver has a shrinking effective emitting area as the frequency goes up because the breakups happen around the outer areas first. Inner areas of the cone follow the voice coil relatively more tightly thus play higher. The smaller effective emitting area higher up makes a cone driver have a smoother beaming.
Quite the opposite of the direct intuition by just seeing their physical shapes.
Villchur thought so, but never achieved it. Allison did with his domes, but by then, omni was all but dead.
Indeed, it's trivial to spray the room with HF having uniform power response anymore, but the artificial soundstage is generated at the expense of imaging, the two being somewhat, largely, even, mutually exclusive under these conditions. Spaciousness cues are now better understood, and consensus favors relatively narrow (~90°) waveguides smartly deployed to manage those cues while also minimizing the influence of the room, as opposed to empowering it. See Geddes, Toole, others....
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Hey! I thought Toole was on my side!
Where does he say horizontal dispersion should be limited to 90 deg? I'm willing to be wrong here, but I thought he was an advocate of horizontal dispersion being a minimum of 90.
To your point about the damage done to imaging when you spray the room with temporally displaced HF sources, I agree, based on listening to a pair of LST 2s. My pet theory is that the best of both worlds would be a vertically aligned WMT or MT array with good impulse response for a clean first arrival AND wide, constant horizontal directivity.
Where does he say horizontal dispersion should be limited to 90 deg? I'm willing to be wrong here, but I thought he was an advocate of horizontal dispersion being a minimum of 90.
To your point about the damage done to imaging when you spray the room with temporally displaced HF sources, I agree, based on listening to a pair of LST 2s. My pet theory is that the best of both worlds would be a vertically aligned WMT or MT array with good impulse response for a clean first arrival AND wide, constant horizontal directivity.
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Okay, but if you switch to a larger radiating diameter, then you're really throwing out constant directivity. Maybe you're not interested in constant directivity, but if you are, remember that the interaction of radiating diameter and waveguide angle sets an absolute ceiling on the CD operating range.
May be, indeed. It's all a tradeoff- coverage vs. control. I like 90 as a design center, intuitively, it makes sense as a balance of reduced sidewall contribution and lack of laserbeam imaging. Your waveguide will be more shallow but will allow you a lower crossover point with the advantages that brings.
No free lunch!
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