TB W3-315E Design

[jimlg]

I have a pair of these I bought a couple years ago, and am trying to find a good design for them. I would love to try a single driver set ala zaphs b3s, or maybe even a TL. I tried a couple searches but did not find much.

Thanks, Jim

http://www.partsexpress.com/pe/showd...number=264-811

[Paul K.]

Using TB's specs I modeled an ML-TL and a 16:1 tapered TL for this driver. I got pretty good results in the tapered TL. I used a line length of 20" with the driver's center located 4" from the beginning (the large and closed end) of the line. The line's width was 4" and it starts with a depth of 8", ending with a depth of 0.5". The net volume of the line is just below 0.2 cubic feet. The first 13.5" of the line is stuffed with ~2 ounces of either Acousta Stuf or poly-fill to achieve a uniform stuffing density of 0.75 lb/cu.ft. The "port" (the terminus) is just a slot in the wall at the line's ending (the open end) of the line, having a width of 4" and a height of 0.5". Overall sensitivity modeled right at 88 dB SPL for 2.83 volts input, and F3 was ~64 Hz. With this 2.83-volt input, the driver's Xmax of 1.25 mm is reached at ~60 Hz. Given more time I'd expect to be able to model a pretty good ML-TL, too, which would be easier to build but would likely have a higher and perhaps audible air velocity out its mass-loading port. I'd attach the system response graph but I haven't tried that yet with this new forum format so I'm not sure how to do it. We could also communicate privately if you wish and I could send you graphs easily that way.
Paul

I have a pair of these I bought a couple years ago, and am trying to find a good design for them. I would love to try a single driver set ala zaphs b3s, or maybe even a TL. I tried a couple searches but did not find much.

Thanks, Jim

http://www.partsexpress.com/pe/showd...number=264-811

[Wolf]

I have a pair of these I bought a couple years ago, and am trying to find a good design for them. I would love to try a single driver set ala zaphs b3s, or maybe even a TL. I tried a couple searches but did not find much.

Thanks, Jim

http://www.partsexpress.com/pe/showd...number=264-811

These drivers have a nasty dip in the pass-band that cannot be filtered out. It's broad, at least -4dB at the bottom, and pretty-much in the middle of the vocal-range. I've used it in 3 different projects now:

"Audinums/Sir Audinums" Tweeter NLA:


And the revamped for new tweeter, "Xenums":


Jim Griffin used the 'original' in an MLTL with a plastic-composite fence-post, dubbed "Smart as a Fence Post". It reached about 50Hz, but power handling/output was limited.

I find they work best in a ported mini-2-way, and used with a sub. I do not have a writeup completed for the "Xenums" yet, but the box is the same as the Audinums enclosure, enhanced with 3/4" thick material this time. If you have questions I can answer them, you can check the writeups in my blog, or you can look at pictures here:
http://s18.photobucket.com/albums/b1...ums_Duoxenums/
Later,
Wolf

[Chris Roemer]

I have a pair of these I bought a couple years ago, and am trying to find a good design for them. I would love to try a single driver set ala zaphs b3s, or maybe even a TL. I tried a couple searches but did not find much.

Thanks, Jim

http://www.partsexpress.com/pe/showd...number=264-811

I have NOT personally used this driver, as Wolf has.

using PE's CLIO files, you can "notch" out what appears to be the most offensive ringing "peak" (around 13k) with this 2 piece notch filter in series with the driver (the cap and coil in parallel w/ each other).

I'd use a Jantzen #18 0.05mH coil with a Dayton poly 3.0uF cap. This suppresses THAT peak by over 12dB. It accentuates a 2nd peak a little, that's higher up, (around roughly +8dB), but at up around 18kHz, it's past MY effective hearing range.

[Wolf]

I have NOT personally used this driver, as Wolf has.

using PE's CLIO files, you can "notch" out what appears to be the most offensive ringing "peak" (around 13k) with this 2 piece notch filter in series with the driver (the cap and coil in parallel w/ each other).

I'd use a Jantzen #18 0.05mH coil with a Dayton poly 3.0uF cap. This suppresses THAT peak by over 12dB. It accentuates a 2nd peak a little, that's higher up, (around roughly +8dB), but at up around 18kHz, it's past MY effective hearing range.

I modeled for running FR, and tilting, notching, etc only emphasized the dip I referred to prior, making it about -6dB or more in magnitude. I really do not believe it would sound very good in FR mode. You'd need a complex BSC circuit to either side of the dip to compensate, and in effect, lose most of the available sensitivity.
Later,
Wolf