Subjective
The 12RD performed well during our subjective evaluation. It doesn’t seem to have that excess of energy in the upper octave of its range that so many boomer woofers do. While transient response in this octave did seem a bit soft, tonal accuracy through this range was good. A tuned enclosure might be a better choice for the severely addicted, but I don’t think that my preference for the good old sealed box is any secret.

The 12RD did a fine job of reproducing everything in our library of CDs, but seemed most at home on anything with a heavy kick drum and an electric bass. It also fared quite well in our string bass and pipe organ torture tests. With a tuned or poorly designed sealed enclosure, one or two notes in a string bass riff will inevitably stick out like a sore thumb. As tested, the 12RD is thankfully devoid of this trait, although the definition of each note in the riff was lacking just a bit. The 12RD also did an admirable job on the dreaded pipe organ. Near the Xmax, it compresses gracefully without a lot of extraneous noises. This is probably due in part to the woofer’s stiff suspension. Cone control is a good thing — the stiffer the suspension, the more power you’ll need. The 12RD does seem a little power hungry, but if that were a crime most of the woofers intended for automotive use would be upstate doing hard time. Power is cheap, so throw some at the 12RD. It could be the best woofer for your current or next system.

Objective
With the coils in parallel, impedance measurements for this unit show a maximum of 16 ohms at 66 Hz and a minimum of 2.2 ohms at 20 Hz. Average impedance measured 4.8 ohms. Out-of-car measurements show a smooth rise in response of about 2 dB below 100 Hz, followed by a 12 dB-per-octave roll off below system resonance. In our test vehicle, this system shows a 1-watt sensitivity that averages 95.8 dB between 20 Hz and 50 Hz and a maximum SPL of 121.5 dB at 50 Hz. In-car measurements also show smooth, extended response with about 4 dB of power compression on the 300 watt (top) trace.