EDIT: OP, I'm not a speaker cab designer, but if I were in your situation I'd look at an Eminence 15" which is more sensitive (>96 db), handles 300 watts RMS (at least), and has comparable lows & better highs (>2,500 Hz) than your blown speaker.
Since I don't know which Eminence 15" would best suit a Hartke Transporter cab, I'd go for:
- louder sensitivity
- higher power handling
- better frequency range
- and a large Xmax (4 mm or greater) (the amount a speaker cone can travel back & forth and remain in control/sound good when reproducing bass frequencies)
at the lowest price and live with any minor mid-bass hump which may be the result of a less than optimal speaker & cabinet match. I could always compensate somewhat with the amp's EQ (if need be).
In short, I'd invest in reliability and loudness over a tonal unknown.
Eminence 15" drivers from US Speaker
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115TP - 1x15 Transporter Cabinet
Hartke for working bass players. Built tough like our world-class XL Series, each features rugged, roadworthy cabinets with metal grills and our versatile TP aluminum-cone drivers for great sound and coverage.
More bass for less. A duct-vented cabinet design combines with low range 15" aluminum-cone bass driver. Power handling of 150 watts at 8 ohms. Wide frequency response of 40 Hz to 2.5 kHz.
Features:
* Special Dual Ported Cabinet Design
* Hartke 15" TP Aluminum-Cone Bass Driver
* Power Handling: 150 Watts at 8 Ohms
* Frequency Response: 40 Hz To 2.5 kHz
* Sensitivity: 96 dB at 1 W/1 M
* Voice Coil: 2"
* Magnet Weight: 60 Oz.
* Single 1/4" Input
* Dimensions: 24"(H) X 24"(W) X 15"(D)
* Weight: 51 lb.