| Test | 12FM6 12V 33 | 12FM6 13.5V 33 | 12FM6 15V 33 | 12FM6 16.5V 33 |
| Frequency response (from 40 Hz to 15 kHz), dB: | +0.04, -0.12 | +0.04, -0.11 | +0.04, -0.12 | +0.04, -0.11 |
| Noise level, dB (A): | -94.3 | -94.6 | -94.7 | -94.9 |
| Dynamic range, dB (A): | 93.6 | 93.9 | 94.1 | 94.1 |
| THD, %: | 0.925 | 1.131 | 1.116 | 1.093 |
| IMD + Noise, %: | 0.843 | 1.101 | 1.043 | 1.065 |
| Stereo crosstalk, dB: | -68.0 | -68.2 | -67.8 | -67.7 |