General Characteristics
Nominal Overall Diameter 306 mm 12 in
Nominal Voice Coil Diameter 25 mm 0.98 in
Magnet Weight 270 g 10 oz
Overall Weight 1.4 kg 3.09 lbs
Flux Density 1 T
Voice Coil Winding Depth 8 mm 0.31 in
Magnetic Gap Depth 6 mm 0.24 in
Thiele-Small Parameters
Nominal Impedance
Voice Coil DC Resistance RE 6.7 Ω
Resonance Frequency ƒS 88.3 Hz
Mechanical Q Factor QMS 18.52
Electrical Q Factor QES 2.85
Total Q Factor QTS 2.47
Mechanical Moving Mass MMS 29.5 g
Mechanical Compliance CMS 110 µm/N
Force Factor BxL 6.24 Wb/m
Equivalent Acoustic Volume VAS 37.5 lt.
Maximum Linear Displacement XMAX ± 0.8 mm
Reference Efficiency nO 1.2 %
Diaphragm Area SD 490.9 cm2
Losses Electrical Resistance RES 67 Ω
Voice Coil Inductance @ 1kHz LE 0.49 mH
Constructive Characteristics
Magnet Ferrite
Voice Coil Winding Copper
Voice Coil Former Kapton
Cone Material Paper
Surround Material Integrated Paper
Dust Dome Material Felt
Basket Material Pressed Sheet Steel
Surround Treatment No
Electrical Characteristics
Nominal Impedance
Rated Power 25 W
Musical Power 50 W
Sensitivity@1W,1m 92.3 dB
25 watts
Available in 8Ω

Typically used in the lower powered 12” amps for studio or practice, the C12R is a clear sounding, sparkling speaker, very sensitive to the character of amplifier. When paired with a stout, rich and warm electronic design it can do wonders. Ampeg® Jets and Reverberockets are just some of the most revered amps that carried C12R as their factory choice.

Guitarist Description
Warm low and mid response with smooth/bright highs. When presented with overdrive distortion, it presents smooth crunch with low-end focus.
Specification Sheet
Product Dimensions
Note: all dimensions are in mm.
User Reviews

I used this in a 5E3 clone, and wow! What a great Tweed sound this speaker yields! With sparkling highs, authoritative mids, and tight lows, it makes my Strat spank and quack, and turns my ES-150 into a throaty monster archtop.


I just replaced the original C12R in my 1962 Gibson Falcon GA19RVT with a reissue C12R, after 46 years the original was a little tired. Good move! This reissue is the ticket!!

Gabby in Hopewell VA

I re-cabbed a Gibson GA15 into a custom made Mather cab modeled on Fender Deluxe 212. I used 2 C12R speakers and the sound is gigantic! The class A 15 watts from the Gibson through these speakers is beyond belief. I did use 2 Weber Beam Blockers to smooth the highs. These are fantastic speakers.

Ed Byrnes