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Author Topic: New speaker idea Alpair 12P / Lowther DX-3 / Acoustic Elegance Dipole 15  (Read 6304 times)

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Marvey

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Lowther DX-3
« Reply #30 on: January 03, 2015, 07:23:21 PM »

@eug: Thanks. Picked two of those AE's up. I would have preferred the LO15 instead of the Dipole15, but heck, at that price, hard to turn down and not going to be picky. The DP and LO are close enough.

It's funny. I just had a conversation with Donald and the designs and how certain requirements lead to similar implementations. I did consider the tweeter (waveguide) idea + mids. Since I'm keeping the x-over simple first order and don't like vertical lobing (with my listening habits, I'm OK with beaming, but I just can't stand vertical lobing), I'd probably end up with x4 midrange around the tweeter, in essence a large co-axial, just like what Donald North did below. The trick of course is to find a good sounding midrange, and for this reason I'd probably avoid pro-drivers in the mid to highs. Pro-drivers tend to handle hundreds of watts and have stiff suspensions which tend not to work well in the home and also sort of goes against my detail/resolution sensibilities.


On the other hand, I just picked up Lowther DX-3s for cheap.


They are really good sounding. Better than the Moth Cicada drivers. Fast, hyper-resolving, amazing transient response. Unfortunately, the Lowthers have a slightly rising response and are very hot up top straight on, even more so than the Cicadas. This means digital EQ or a notch filter or shelf filter or a strange phase plug, or a combination thereof. +10db from 8-11kHz. That's just nutty bright / annoying (even off-axis). Those are someone else's measurements below, and they are consistent with quick measurements I have taken so far.

« Last Edit: January 14, 2015, 06:18:36 AM by marvey »
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zerodeefex

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Re: New speaker idea and Alpair 12P driver
« Reply #31 on: January 03, 2015, 08:15:09 PM »

Holy balls. I just realized you take your speaker measutements at 100dB.
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Thad E Ginathom

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Re: New speaker idea and Alpair 12P driver
« Reply #32 on: January 04, 2015, 07:47:13 AM »

...  you take your speaker measutements at 100dB.

With industrial ear protection?
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Marvey

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Acoustic Elegance Dipole 15
« Reply #33 on: January 13, 2015, 11:46:16 PM »

So I picked up the Acoustic Elegance Dipole 15 from ebay.




These things are heavy. The weigh like 5 times more than the Betas. The paper cones are treated with a layer of semi-sticky stuff on the front size. Let me be somewhat succinct:

I prefer the $79 Eminence Beta 15As. I stated previously that I would have preferred the AE LO15, but figured the Dipole15s would be suitable. The crucial thing that I did not take into account is that the Dipole15s have sucky efficiency at 90db. (The LO15s are 93db). My preference has always been for higher-efficiency drivers. Although I would be generalizing, for some reason, higher-efficiency drivers tend to sound "faster" to me. In comparison, the Eminence Beta 15A's rated efficiency is 98db - and this jives with my observations using both drivers (at least relative efficiency differences between them).

The AE Dipole15s do a few things better. They are better damped, they have less of a paper coloration, they have a tighter more high-fidelity sound. What they lack is the rawness, energy, snap, punch, and speed of the Betas. Although per spec, the Betas have a Qts of about 0.5 and the Dipole have a Qts of about 1.0; the Dipoles in the 2' baffles roll-off in the bass near the same point around 50Hz - maybe a few Hz lower. In theory, the Dipoles should extend lower. I suspect the following causes: width of the baffle is primary limitation, specs for the Beta 15 are wrong - the Qts is higher - probable given the cheap light magnet.

I wouldn't say the Dipoles are worse. It's just that I prefer the liveliness and uptempo nature of the Eminence Betas. The Dipoles have a hard time keeping up with the Lowthers.
« Last Edit: January 14, 2015, 06:18:50 AM by marvey »
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OJneg

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Re: New speaker idea Alpair 12P / Lowther / Acoustic Elegance
« Reply #34 on: January 14, 2015, 12:44:53 AM »

Possible wear-in issues? Any idea how heavily they were used before?

Mind posting FR measurements on axis with the woofer? I'm curious if these do really extend flat to 2k. How are you crossing them at the moment?
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Marvey

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Re: New speaker idea Alpair 12P / Lowther / Acoustic Elegance
« Reply #35 on: January 14, 2015, 06:17:57 AM »

No idea how much they were used before. Put the Beta 15s back - so much better. More resolving, faster. Hits on the beat. Snaps.

The AE Dipoles probably would extend flat to 2k since the cone is damped with a later of glop over it. I expected better, but maybe the Qts of the AE Dipole is simply too high at 0.94. I should swap in your Eminence Alpha 15s and see what happens. Then again, I've always liked the lightweight thin paper cone sound for big woofers, JBL, Altec, Beyma, Eminence, etc.
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OJneg

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Re: New speaker idea Alpair 12P / Lowther DX-3 / Acoustic Elegance Dipole 15
« Reply #36 on: January 14, 2015, 07:01:05 AM »

I would describe the Alphas as a fast but muddy sound. Becomes non-linear at high SPLs as you can imagine.

I'm just surprised you're not getting any more extension out of them. Super low Fs and high-ish Qts should be a major win on paper. No worries if you don't like them; you know I'll buy them off you eventually.
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Marvey

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Re: New speaker idea Alpair 12P / Lowther DX-3 / Acoustic Elegance Dipole 15
« Reply #37 on: January 14, 2015, 07:26:59 AM »

Yeah, the Dipole 15s are now officially part of the Changstar speaker driver loaner program.

The Dipoles had a better sense of heft or thickness (I actually didn't like this); but with the measurement mic, all the x-over and bass EQ settings were exactly the same as the Betas to maintain optimal response. The only change being volume, cranked up about 5-6db over the Betas.
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dBel84

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Re: New speaker idea Alpair 12P / Lowther DX-3 / Acoustic Elegance Dipole 15
« Reply #38 on: February 06, 2015, 01:34:16 AM »

Marv , have been meaning to ask you if you have any experience with these drivers

http://www.commonsenseaudio.com/nirvana.html

From what I can make out - same factory / people behind Lowther.

..dB
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Marvey

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Re: New speaker idea Alpair 12P / Lowther DX-3 / Acoustic Elegance Dipole 15
« Reply #39 on: February 06, 2015, 01:55:42 AM »

Haven't tried them ... yet. Really good pricing. No much info on them.
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