Keeping an eye on Selenium
Selenium was bought recently by Harman and thus "merged" with JBL. Hopefully, a mariage for the best on the long term if shareholders' interests do not prevail over the rest...but that's not the subject.
We'll need to keep an eye on their speakers since many 15" come out with Mms around 70 to 80 g. Haven't gone through their whole production yet to find out all the lower values.
Of particular interest to me is also the particulalry high Qms values many of their (apparently new) drivers exhibit, which according to my equations [Rms= (2Pi x Mms x Fs)/Qms] lead also to a low Rms - mechanical resistance, which is sometimes assumed to influence positively on the articulate sound at low-mid listening levels; granted, not everybody agrees on the pertinence of the above assumption and equation.
Chris.
Selenium was bought recently by Harman and thus "merged" with JBL. Hopefully, a mariage for the best on the long term if shareholders' interests do not prevail over the rest...but that's not the subject.
We'll need to keep an eye on their speakers since many 15" come out with Mms around 70 to 80 g. Haven't gone through their whole production yet to find out all the lower values.
Of particular interest to me is also the particulalry high Qms values many of their (apparently new) drivers exhibit, which according to my equations [Rms= (2Pi x Mms x Fs)/Qms] lead also to a low Rms - mechanical resistance, which is sometimes assumed to influence positively on the articulate sound at low-mid listening levels; granted, not everybody agrees on the pertinence of the above assumption and equation.
Chris.
cheap and affordable 55 g Mms, beautiful basket 
, some good subjective review: 15W500 - LF Ferrite Driver
, some good subjective review: 15W500 - LF Ferrite Driver
Thanks. That's what I measured on a pair of 416-8A that GPA reconed for me. The originals are a bit lighter.
18S 15W500 & 15MB606 are good ones (same cone/surround).
As is the beyma 15MI100.
BTW, the BD-15 is effectively a 15MI100 with different motor and spider but shares the excellent cone/surround and basket.
All these drivers are midbasses/midranges and don't lead themselves easily to bass/sub usage in passive designs.
As is the beyma 15MI100.
BTW, the BD-15 is effectively a 15MI100 with different motor and spider but shares the excellent cone/surround and basket.
All these drivers are midbasses/midranges and don't lead themselves easily to bass/sub usage in passive designs.
Yes, indeed. I belong to the faction of users of larger 100+ dB systems involving mid-high horns + classical (non horn-based) bass enclosures in the range of 200-250+ liters (6-8 cubic feet). Lightweight 15" cones in the area of 70 g need that kind of volume.
Chris.
in the 1KHz->4KHz region my neodymium Peavey SC15~52g mms) is less sensitive than an old EVM15B - wonder if part of that is due to the Peavey's 4" voice coil vs 2.5" for the EV? With a little Karlson there's only about 60 liters top for a 15"
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Of particular interest to me is also the particulalry high Qms values many of their (apparently new) drivers exhibit, which according to my equations [Rms= (2Pi x Mms x Fs)/Qms] lead also to a low Rms - mechanical resistance, which is sometimes assumed to influence positively on the articulate sound at low-mid listening levels; granted, not everybody agrees on the pertinence of the above assumption and equation.
Chris.[/QUOTE]
The link to a (short) discussion on Rms http://www.diyaudio.com/forums/multi-way/131739-low-rms-woofers-your-experience.html
In that thread, someone pointed to the fact that woofers with low Fs (as in the past) have become hard to find. So let's look for a 15" with a low Mms but nonetheless low Fs (which would tend also towards a low Rms...).
Chris.[/QUOTE]
The link to a (short) discussion on Rms http://www.diyaudio.com/forums/multi-way/131739-low-rms-woofers-your-experience.html
In that thread, someone pointed to the fact that woofers with low Fs (as in the past) have become hard to find. So let's look for a 15" with a low Mms but nonetheless low Fs (which would tend also towards a low Rms...).
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