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 1.1 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 3.25 Ω 6.75 Ω 12 Ω
Resonance Frequency ƒS 102 Hz 115 Hz 113.3 Hz
Mechanical Q Factor QMS 19.8 16.4 17.41
Electrical Q Factor QES 0.90
Total Q Factor QTS 0.52 0.82 0.86
Mechanical Moving Mass MMS 34.9 g 33.4 g 35.6 g
Mechanical Compliance CMS 70 µm/N 57 µm/N 55 µm/N
Force Factor BxL 11.65 Wb/m 13.7 Wb/m 18.3 Wb/m
Equivalent Acoustic Volume VAS 23.6 lt. 19.6 lt. 19 lt.
Maximum Linear Displacement XMAX ± 1 mm ± 1 mm ± 1 mm
Reference Efficiency nO 4.47 % 4.43 % 3.89 %
Diaphragm Area SD 490.9 cm2 490.9 cm2 490.9 cm2
Losses Electrical Resistance RES 120 Ω 210 Ω 360 Ω
Voice Coil Inductance @ 1kHz LE 0.61 mH 0.84 mH 1.36 mH
Constructive Characteristics
Magnet Ferrite
Voice Coil Winding Copper
Voice Coil Former Kapton
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 100 W
Musical Power 200 W 200 W 200 W
Sensitivity@1W,1m 99.4 dB 99 dB 99 dB
100 watts
Available in 4Ω, 8Ω, 16Ω

While not strictly a vintage reissue, the C12K is the first design that Jensen developed in the early ‘90s. It is tonally inspired by the classic vintage ceramic Jensen, but with a substantially stronger voice, full bass and smooth top end. The C12K became one of the speakers of choice for Fender®, used in a myriad of world-selling models. Vintage tone with modern power handling and dynamics are the key virtues of the C12K.

Guitarist Description
A real workhorse, heavy on the mids with a solid, straightforward tone. Presented with overdrive distortion it powers through with lows that are bold and heavy.
Specification Sheet
Product Dimensions
Note: all dimensions are in mm.
User Reviews

We have used them with high gain sounds in our 2x12 Magma Xaman cabs, the tone is what we were looking for! Deep bass, warm mids and sweet highs, very balanced!


I actually ended up purchasing a pair of C12K's. I installed them in my Fender Twin and absolutely love the sound. I was looking for speakers that wouldn't break up quickly because I like to have a lot of headroom in order to get some jazz tone and also make good use of my effects pedals. These speakers fit the bill and if I ever need to replace them I'm sure I'd just buy another pair as long as they're available


I totally rebuilt a '72 Fender Twin and added a little lower end to it by installing some C12K's. Mostly I play a new Benedetto Benny and/or a '71 Les Paul thru it, and it rocks the house. Even the other "players" in the audience have to comment on the great "tone" I get. I love it, and being in 4 groups I use it 3 - 5 times a week.

Ed in Hobe Sound, FL