The Betsy
Betsy Fullrange Driver


The Betsy-k
Betsy-K Fullrange Driver


Wild Burro's speakers

Betsy was my first Burro (she lives happily on my father's farm in Nebraska). She's also the first speaker from Wild Burro Audio Labs. BetsyK is short for Betsy with-a-kick (she's got a bigger motor). That doesn't make her a better speaker, it just means she's ideal for different situations.

The Betsy

$100/pair Betsy is made for open baffles. I use the baffle outlined on the projects page. You might try a JE Labs style OB. Or a big sheet of ply with a hole cut in it. Or you might want to get fancy with some helper woofers. Or an H-frame sub. Betsy is worth the effort.

The Betsy-k

$110/pair BetsyK was designed for resonant enclosures. Given her high compliance, the best options are big. My pair lives in a pair of 6'6", 13.25x20" BIB cabinets. They should also work well in Metronome's or BVR's. The easiest option is a one or two cu. ft. sealed box. The former will give you warmer bass, the latter, a bit more damped response. You can use a two or three cu. ft. ported enclosure, if you tune it low. You'll probably want either some baffle step compensation and/or wide baffles close to room boundaries (not needed with BIB's).

Features

Cone: The cone is the key to Betsy's great mids and extended frequency response. It is special natural fiber kraft paper augmented with a couple of space age materials (carbon fiber and Kevlar). It is rigid, well-damped, and ultra-light (less than 10 grams!).

Suspension: Old fashioned, good sounding cloth accordion surround and a nice big spider contribute to linear excursion. Betsy's awesome cone just doesn't need a big roll of rubber to tame it.

Whizzer: Betsy has a small, super stiff (due to the curve) whizzer. To my ear, it stays out of the cones way better than a larger one. I think the Seas Exotica folks agree.

Excursion: Betsy has about 2mm. I listen to the OB's near field, and they get plenty loud. 2mm is more than enough for the BetsyK in BIB's. Sure, we could use a longer voice coil. But it would weigh more. And the inductance (thus distortion) would be higher. If you want to hook a big solid-state amp up and pound your little 8" fullranger in a box, Pioneer makes nice speaker. Or, you can buy the Seas Exotica. I get by fine. And I do listen to some heavy stuff with a 50-watt chip amp.

Basket: Good ol' steel. Maybe a cast basket would sound a tiny bit better, but it would cost much more. Of course, you can glue stuff to the basket to your hearts content. I find she sounds incredible as she comes out of the box.

Motor: Ceramic. Betsy's 10 oz. motor has a bumped and vented back plate. BetsyK's is a basic 20 oz. slug. Maybe someday Betsy'll go all fancy and get some Alnico. Ya' never know.

Specs: V2 (red line) is the Betsy. V1 (blue line) is the BetsyK. VAS is given in liters.

BETSY:
Re 5.9 ohms
Fs 49.630Hz
Sd 22.966
BL 4.166
Qms 4.567
Qes .945
Qts .783
Spl 92.4db
Vas 86.387L
Mms 8.916g

BETSY -K:
Re 5.7 ohms
Fs 49.959Hz
Sd 22.966
BL 5.471
Qms 2.798
Qes .548
Qts .458
Spl 94.6
Vas 82.914L
Mms 9.167g