In woofers of this size the lower it is the more a driver has been biased towards bass reproduction the higher the more midrange. But it's more a function of how easily the driver will produce those frequencies rather than how well.
Earl is using the driver up 800 or 900 Hz in his designs with 15" woofers. Having a significantly extended response beyond that does not serve much purpose and makes it harder to use a passive crossover as the driver rolloff is outside the crossover region. The driver he picked is very linear within it's passband and only has one peak to be dealt with in the crossover.
Some people use the 15" drivers much higher in frequency and use the extended response, but using the driver that high will create a directivity mismatch.
Some seem to have developed a liking to the sound of drivers with certain specifications and seek them out. You might agree or not, but it is an opinion rather than a proven fact.
System design, intended frequency range, constraints of matching with other drivers etc. seem to make it hard to choose the best driver for that system solely based on how heavy the cone is.
Marco's quote above gives a hint. One thing you will notice with drivers that have a lot of Bl is that the frequency response is tilted up and needs EQ to flatten it out. Lot's of hifi drivers have that built in to their specs to come flat out of the box.
mark100 quoted Tom Danley not that long ago maybe even here with a good explanation.
I've never given cone mass much importance. What large drivers need to do well is to handle the first few problem areas (rim resonance, cone breakup, etc.) that are inherent in these larger drivers. If the driver does that well then I'd consider it regardless of the cone mass. The LF lumped parameter variables are pretty much irrelevant to me. DSP can handle anything down at those frequencies. The sensitivity is a major factor of course as it needs to be matched to the compression driver, although with an active DSP crossover this too is pretty much irrelevant (relevant in a passive crossover however.)
As long as the Klippel and distortion measurements are fine, the discussion about cone mass is a little irrelevant. Obviously when the frequency response is adequate enough.
When that data isn't available, it's very hard to say anything beforehand.
But that also counts for any other speaker in general.
When that data isn't available, it's very hard to say anything beforehand.
But that also counts for any other speaker in general.
G'day b_force,
When you said:
"When that data isn't available, it's very hard to say anything beforehand. But that also counts for any other speaker in general"
I got excited that your Sound Projects systems might have some insightful and usefully characterising published data.
I really appreciate JBL, Gedlee and other manufacturers that publish data and whitepapers showing what is possible in development and measurement of the final product.
When you said:
"When that data isn't available, it's very hard to say anything beforehand. But that also counts for any other speaker in general"
I got excited that your Sound Projects systems might have some insightful and usefully characterising published data.
I really appreciate JBL, Gedlee and other manufacturers that publish data and whitepapers showing what is possible in development and measurement of the final product.
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I don't know why 14" woofer has never been popular, but I think it is a pretty reasonable size for domestic 2 way, especially in dual woofer configuration. I have been using JBL 1400ND.
I like the sensitivity - but the 38Hz Fs for a driver that large is disappointing. And it has a pretty low Qts, of 0.249. The Mms is 67.14 grams.
The woofer I used in my MLTL-10 speakers, is the SB Acoustics SB23NRXS45-4, which is 92dB sensitivity, Fs 27Hz, Qts 0.3, and Mms is just 27.2 grams. I am looking for a woofer that is better - more sensitive, with the same or lower Fs and Mms, and maybe higher Qts.
The MLTL-10 speakers that I built are F3 at about 27Hz, and in room F6 is about 20Hz. I have redesigned the lower portion of the transmission line, and the F3 point should be about 25Hz; and the in room response should be better, since the terminus opening moved from the lower front corner, to the lower back corner of the cabinet.
The woofer I used in my MLTL-10 speakers, is the SB Acoustics SB23NRXS45-4, which is 92dB sensitivity, Fs 27Hz, Qts 0.3, and Mms is just 27.2 grams. I am looking for a woofer that is better - more sensitive, with the same or lower Fs and Mms, and maybe higher Qts.
The MLTL-10 speakers that I built are F3 at about 27Hz, and in room F6 is about 20Hz. I have redesigned the lower portion of the transmission line, and the F3 point should be about 25Hz; and the in room response should be better, since the terminus opening moved from the lower front corner, to the lower back corner of the cabinet.
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What's the whole deal with the Mms again?
As long as it performs well, freq resp is usable and distortion is low, Mms is irrelevant.
As long as it performs well, freq resp is usable and distortion is low, Mms is irrelevant.
It's either/or.
38Hz Fs isn't disappointing, it's impressive.
The SB23NRXS45-4 is a typical sloppy hifi woofer > basically a mid range driver with air pump capability. An exercise in beating Hofmann's Iron Law.
This is one of the best compromises between mid range and low end. And yes, Qts is low:
Why compare the SB23 at all with a 15" driver... the SD (cone area) of that Precision Devices driver is 3.9 times as big as the SB. The moving mass of the PD is just 2.4x as much though...
Apples and oranges?
Apples and oranges?
Hows this for a list>?
Oberton 15NMB600 - 15" Subwoofer
RCF MB15N351 - 15" Mid Bass
Eighteen Sound 15NMB420 - 15" Mid Bass
Precision Devices PD.153C002 - 15" Mid-range
The Oberton looks like a good fit for the cutout I have already
Oberton 15NMB600 - 15" Subwoofer
RCF MB15N351 - 15" Mid Bass
Eighteen Sound 15NMB420 - 15" Mid Bass
Precision Devices PD.153C002 - 15" Mid-range
The Oberton looks like a good fit for the cutout I have already
We make speakers that are low mass for a reason. So lower mass is better than greater mass.
Is that the Royal "We" and what is their reason ?
Maybe it is for the unstated reason above but it is certainly not universally true.
Well...I am trying to figure it out....The Oberton I listed above, has about the highest BL and lowest Mmd...kinda makes it a no brainer.
Heres one that is the epitome of a lower mass 15"...Why isn't this driver the holy grail if low mass is King
Oberton 15L400 - 15" Subwoofer
The15NMB600 has my attention. Any nay sayers?
Heres one that is the epitome of a lower mass 15"...Why isn't this driver the holy grail if low mass is King
Oberton 15L400 - 15" Subwoofer
The15NMB600 has my attention. Any nay sayers?
How so better if freq resp is usable and distortion is low enough or equal?
Like I said before.
