General Characteristics
Nominal Overall Diameter 307 mm 12 in
Nominal Voice Coil Diameter 50 mm 2 in
Magnet Weight 1450 g 51 oz
Overall Weight 4.3 kg 9.48 lbs
Flux Density 1.15 T
Voice Coil Winding Depth 10 mm 0.39 in
Magnetic Gap Depth 8 mm 0.31 in
Thiele-Small Parameters
Nominal Impedance 16Ω
Voice Coil DC Resistance RE 6.7 Ω 12 Ω
Resonance Frequency ƒS 79 Hz 85 Hz
Mechanical Q Factor QMS 12.07 12.07
Electrical Q Factor QES 0.62
Total Q Factor QTS 0.47 0.59
Mechanical Moving Mass MMS 32.2 g 28.5 g
Mechanical Compliance CMS 126 µm/N 123 µm/N
Force Factor BxL 14.73 Wb/m 17.19 Wb/m
Equivalent Acoustic Volume VAS 43.1 lt. 42.1 lt.
Diaphragm Area SD 490.9 cm2 490.9 cm2
Voice Coil Inductance @ 1kHz LE 0.84 mH 1.21 mH
Constructive Characteristics
Magnet Ferrite
Voice Coil Winding Copper
Voice Coil Former Nomex
Cone Material Paper
Surround Material Integrated Paper
Dust Dome Material Non-treated Cloth
Basket Material Pressed Sheet Steel
Surround Treatment Yes
Electrical Characteristics
Nominal Impedance 16Ω
Rated Power 100 W 100 W
Musical Power 200 W 200 W
Sensitivity@1W,1m 99.5 dB 99.5 dB
100 watts
Available in 8Ω, 16Ω

The C12K-2 is a step forward from the C12K.  It has a different cone membrane which grants a more extended treble response to increase the detail and the shimmer of the tone, yet retains a well contoured smoothness. Equally at home with clean and mid-gain crunch tones, the C12K-2 offers an outstanding response to the player’s touch. When used with higher gain tones, it offers a powerful, rounded, organic tone that delivers a full-bodied thickness to single note lead runs.

Guitarist Description
Fat, smooth and warm. Presented with overdrive distortion, it exhibits a silky, smooth, lead fuzz.
Specification Sheet
Product Dimensions
Note: all dimensions are in mm.
User Reviews

I installed two of these C12K-2 speakers into an Orange PPC212 closed-back cabinet to use with my Orange Dual Dark 50 amplifier. They are a perfect match for both heavy metal and hard rock guitar riffs, but can turn around quickly and be equally adept at clean, intricate tones that work well with jazz and country styles as well. Tone descriptions aren't always accurate, but the ones Jensen provides for these speakers are very accurate. These speakers provide tight (not flubby at all) bass, mids that are present, but not overbearing, highs that are very smooth and not piercing, and overdrive tones that are not fizzy or harsh, but smooth and, as stated, creamy.

In my opinion, this is like the missing link between a Celestion Vintage 30 and Celestion G12H Anniversary. No ice pick / ear fatigue issues like with a Vintage 30, but plenty of lows and low mids, like a G12H. The price for these speakers is very reasonable, too. I highly recommend them for closed-back 2x12 cabinets with British-style amplifiers. I imagine they would also provide a very nice tonal alternative in Fender-style amps as well, toning down the piercing highs that sometimes result from those circuits. The Jensen C12K-2 is a contender in the field of British-style speakers, providing a very versatile tonal combination unique from other companies' speaker offerings.

Eric R.