And he's correct, of course. You have to consider the "mechanics" of the forces involved (all of which come from the magnet/voice coil interaction) and then what surfaces any "extraneous" motion can radiate sound from. All drivers are ultimately "magnet mounted" . . . when the intervening connection is through the basket to the baffle then there is likely to be unwanted radiation from the baffle . . . especially a problem with dipoles where the baffle itself is likely to be light weight and have little to no bracing. That's why the magnet mount rather than basket mount on ORION, and why the equivalent driver in LX521 is not magnet mounted (although it could be). In LX521 the baffle size and shape makes secondary radiation (almost) not an issue in the range over which those drivers operate (just as basket resonances hardly matter if the basket is not connected to a sound board/baffle). Magnet mounting the mid in the LXmini serves to decouple reactive motion of the motor from potential radiating surfaces (not to mention the obvious question of where one would attach a basket mount anyway, since there is no baffle on the midrange driver).
This has been a hallmark of Linkwitz designs since he first got "out of the box". It's a "natural" property of dipoles and omnis anyway, but SL still goes out of his way not to mess it up. Worth noting, though, is that much depends on the quality of the recording. If you put a monaural "click" in any of his speakers (make it the actual source rather than a "reproduction with clues") localization of the speaker is instant and precise.
I could be wrong about a lot of things, but by asserting my opinions, playing devils advocate, I hope to learn a few things. No personal attacks intended.
I looked up the smallest Seas cone type driver (a 4 inch), assuming that would be the one SL is using for the upperband, and the Seas published graph showed a pretty substantial rolloff above about 12kHZ. That's when I thought he might have done better with the Peerless TG driver which is pretty flat to 16kHZ (8 ohm version). I didn't realize that he had quite a bit of active EQ going on. I'm sure that helps. I can't help thinking that he chose the Seas driver because of the reputation of Seas being very high end, as opposed to Peerless having more of a hit and miss cheaper reputation.
I'm still not convinced that magnet mounting a driver is any better. Something has got to dampen the front of the basket or it could ring.
I looked up the smallest Seas cone type driver (a 4 inch), assuming that would be the one SL is using for the upperband, and the Seas published graph showed a pretty substantial rolloff above about 12kHZ. That's when I thought he might have done better with the Peerless TG driver which is pretty flat to 16kHZ (8 ohm version). I didn't realize that he had quite a bit of active EQ going on. I'm sure that helps. I can't help thinking that he chose the Seas driver because of the reputation of Seas being very high end, as opposed to Peerless having more of a hit and miss cheaper reputation.
I'm still not convinced that magnet mounting a driver is any better. Something has got to dampen the front of the basket or it could ring.
SL works with SEAS because SEAS works with SL...they have been willing to tailor the characteristics of some drivers to better fit his needs. As dewardh asked, to what would you mount the rim of this driver that has no baffle?
That's why I suggested that I would have a very small and narrow but very dense baffle for the upperband driver, rather than mounting it by its magnet. The acoustic effect of this "baffle" might be less than optimal for different reasons though, so it might actually sound better the way SL did it. Besides, a little ringing might actually sound good to some people. A sort of tight reverb kind of thing at certain frequencies. Maybe just a heavy brass ring, 1/2 inch by 1/4 inch, to put a bunch of mass on the rim of the driver for damping (?)...
Hold the driver in one hand by the magnet and tap on the basket (with a screwdriver or something else hard) with the other. Hear any ringing? If yes (and it's in the intended range of operation) then toss the driver . . .
Actually magnet mount in this case could not be for mechanical reasons (like in Orions). But acoustics. The total sum of 'acoustic disruptions' at the back resulted in the intended polar response. From the given plot it looks like cardioid -> dipole -> forward directional. Although very hard to see.
A classical polar plot (those round things) should make things clearer.
True I think, but also Siegfried told me the new woven poly cone SEAS drivers are very very good even though not the most expensive SEAS drivers by far, so:
"Use the right driver for the job, not the "best"."
"the SEAS drivers are very consistent so I know people will get the same results I get"
He's a veritable Yoda of speaker design 😉
It is interesting that the driver model numbers used for the big LX include "SL" in them.
"Use the right driver for the job, not the "best"."
"the SEAS drivers are very consistent so I know people will get the same results I get"
He's a veritable Yoda of speaker design 😉
It is interesting that the driver model numbers used for the big LX include "SL" in them.
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The Seas FU10RB-H1600-04 4" 4" from the LX Mini is currently sold out.
The CSS VWR 126X uses the same cone material, in a similar size, with exceptionally low distortion and wide bandwidth. It is also cheaper. Might be worth considering if you're impatient.
Here's a Klippel test of it, done by Erin at DIYMA
Car Audio | DiyMobileAudio.com | Car Stereo Forum
I fail to see how changing a driver in a closely EQed and studied system to save 10 bucks and a week would serve anyone in the long run.
Beside the cone material (maybe) everything is different, and the diameter are different to start with (98mm vs 126mm)
Beside the cone material (maybe) everything is different, and the diameter are different to start with (98mm vs 126mm)
I completely agree, but always good to know about a potentially great driver for some purpose....
TG9FD10-04
An extraordinary driver, especially considering the price. Should I decide to do a LXmini "clone" I won't look any further . . .
The SEAS material is is called Curv and made by Propex in Germany. SEAS purchases that material and then sends it to the cone maker to have it molded to the cone shape. I'm sure there are knock-offs of Curv in China, (they knock off everything), so it's an open question whether CSS is using the actual Curv material. You'd think they'd use the name on datasheets if this was the case, but who knows? Curv is pretty expensive stuff, btw.
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This isn't rocket science: weaving any material will change it's stiffness and it's strength.
It's the same reason that woven glass is lighter and stronger than fiberglass mat.
An externally hosted image should be here but it was not working when we last tested it.
CURV is basically the same stuff that sandbags are made out of right?
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FYI Madisound is now accepting orders for the LXmini kit (drivers, miniDSP & Acoustastuff) priced at $398 or about 10% off list. Shipping is expected in about 2 weeks when the upper driver is restocked.
That's the driver I've been recommending (from Peerless). I feel that they compete well with the very best drivers out there, at a fraction of the cost, and they may in fact be the best for doing 400HZ - 15kHZ, all things considered. This driver doesn't really need any EQ over that frequency range. The 8 ohm version seems to have slightly more extension on the high end (avail. at Madisound). It's only shortcoming is that it's sensitivity is 85dB, which is a few db better than the Seas SL is using. If you're bi-amping that's of little consequence.
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You really think Seas buys the materials and then sends it to the cone manufacture in China? Or does it make more sense for the cone manufacture in China to buy the material, and then sell Seas a finished product?
I don't know about the rest of you guys, but the later makes more sense to me.
I don't know about the rest of you guys, but the later makes more sense to me.
In fact, it's the former. My knowledge of this is more than speculation. Of course, the manufacturer drop ships the material to the cone supplier, but SEAS actually owns it. This goes back a couple of years, but nobody else was using Curv at the time, and the cone supplier didn't want to invest in a new, unproven material. So SEAS didn't have any other choice.
lol how much did Scanspeak paid you? 😀
btw. How do you think Seas FU compared to SS 10F which was favourably tested by Zaph and Mark K?
www.audioheuristics.org/measurements/Testing/Midrange4/midrange_4_test_data.htm
But even 10F they admitted it's good to 4k (uneq'd I suppose) ?
jmsent, as an insider what is your opinion on these cruv cones compared to the (more expensive) magnesium ones?
SL did use magnesium cones back in the Orion and switched to the curv in its recent designs.
For example U22REX/P-SL vs W22EX001.
SL did use magnesium cones back in the Orion and switched to the curv in its recent designs.
For example U22REX/P-SL vs W22EX001.
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