Did you try Peavey first?
http://www.peavey.com/support/techno...blackwidow.cfm
And I quote:
15" SPEAKERS
Sound Reinforcement and PA Applications
1505DT-8 Black Widow
The 1505DT is an 8 ohm, 15" Black Widow/Super Structure speaker with a curvilinear cone for extended bandwidth. Offering a rare combination of usable frequency response into the mid-range with a smooth powerful low end, the 1505DT, Kevlar cone and long voice coil provide excellent linearity at high drive levels. Excellent as a woofer in multi-way enclosures or as the bottom end in a two-way system.
1505KADT-8 Black Widow
The "KA" version of the 1505 has a medium length voice coil for higher efficiency and even greater bandwidth than the 1505DT-8.
Musical Instrument Applications
1501DT-4 Black Widow
The 1501DT is a 4 ohm, 15" Black Widow/Super Structure speaker specifically voiced for musical instrument use. A "classic" sound is achieved by using a specially developed high density curvilinear paper cone, and incorporating a one-piece aluminum dust cap and voice coil former. Sustain is enhanced while retaining control of the overall tone. Obvious applications include lead guitar and steel guitar.
1502DT-4 and 8 Black Widows
The 1502DT is a 15" Black Widow/Super Structure speaker with a straight-sided, ribbed, Kevlar impregnated cone for the strength required to handle pounding bass lines. Primarily a bass guitar speaker, the 1502 is versatile enough to be used for lead guitar, keyboard, and general purpose low frequency sound reinforcement. The 1502DT-4 is equipped with medium length voice coils for efficiency and high output and is available in 4 and 8 ohm versions.
1505DT-4 Black Widow
The 1505DT-4 is a 4 ohm, 15" Black Widow/Super Structure speaker with a curvilinear Kevlar impregnated cone for extended smooth response. While used as a bass guitar speaker, the high frequencies have a little extra "bite." Long voice coil maintains linearity at high drive levels.
Special Applications
1504DT-4 Black Widow
The 1504DT is a 4 ohm 15" Black Widow/Super Structure speaker designed specifically for use in horn loaded enclosures. Utilizing a straight-sided, ribbed, Kevlar impregnated cone for maximum rigidity, the suspension is more compliant (softer) for higher linearity when driving a horn loaded cabinet.