I'm looking into a larger format CD build with a 15" woofer that must make it to 900hz or so.
I currently have a SEOS 15 and BMS 4550 that will suffice until I choose a 1.4" beryllium CD and waveguide.
The 15 inch woofer must be able to supply great midbass and I am not considering the TD15M because it has too limited an XMAX and too fragile a cone.
The two choices I am looking at are the 15 used by Earl Geddes in the NS15 (15nbx100) which has an exponential cone and the 15sw115 which has a radial cone shape with the following respective responses:
15nbx100
https://www.bcspeakers.com/en/products/lf-driver/15-0/8/15nbx100
15sw115
https://www.bcspeakers.com/en/products/lf-driver/15-0/8/15sw115
Dr. Geddes crossed over the 15nbx100 at 1000hz. To get the greater XMAX and motor strength, is the 15sw115 OK to use in its place?
I currently have a SEOS 15 and BMS 4550 that will suffice until I choose a 1.4" beryllium CD and waveguide.
The 15 inch woofer must be able to supply great midbass and I am not considering the TD15M because it has too limited an XMAX and too fragile a cone.
The two choices I am looking at are the 15 used by Earl Geddes in the NS15 (15nbx100) which has an exponential cone and the 15sw115 which has a radial cone shape with the following respective responses:
15nbx100
https://www.bcspeakers.com/en/products/lf-driver/15-0/8/15nbx100
15sw115
https://www.bcspeakers.com/en/products/lf-driver/15-0/8/15sw115
Dr. Geddes crossed over the 15nbx100 at 1000hz. To get the greater XMAX and motor strength, is the 15sw115 OK to use in its place?
check out the 15NDL88. lower Xmax/BL but more efficient, lower mass and no nasty FR spike next to your crossover
Do you mean the AE TD15M? I’ve been running them for years and no issues with either the xmax or brittle cone. Best sounding 15” I’ve ever heard.
What is the intended crossover point to the subwoofers? This should also be considered in your choice of driver, no need for +/-13 mm xmax if 6mm will give you the LF Spl you desire.
How about one of the Eighteen Sound offerings?
How about one of the Eighteen Sound offerings?
I considered it but it's unobtanium. I called and it's been out of stock for 6 months.
Geddes was wrong eh?
Did you use the 15NDL88 or know of anyone that did? That actually looks really good.
You’re right. It is the X. The CD is a JBL 2441 with a Radian mylar surround diaphragm. The horn is a 300hz Edgarhorn.
15NDL88 might not have been available when Geddes was designing the NS15. I have 4 of them to use in an upcoming project but no, I haven't heard them yet. They are optimized for direct radiator usage with more HF extension. I think the drivers you mentioned are geared more towards horn loading with a more limited bandwidth.
Here's a review of the 12NDL88 from AudioExpress. I think the 15" has the same motor with the addition of a shorting ring.
https://audioxpress.com/article/Test-Bench-B-C-Speakers-12NDL88-12-Woofer
You usually can't use the high X-max of a woofer since it introduces Doppler- and IMD as long as you want to use it in the midrange too.
That's a clean driver up top. I like it. I imagine the 15" version will be excellent. Great price too.
I'd like to stay with an accordion surround too, so it is on the list.