The Eminence 4015LF fared well regarding distortion, the dB figures are about 4 dB low due to a calibration error.

30 Hz 108 dB 70% distortion (below box tuning, Fb)

35 Hz 114 dB 18% (below Fb)

HP filters are important!

40 Hz 114 dB 2%

45 Hz 118 dB 11%

50 Hz 120 dB 13% (over Xmax)

55 Hz 121 dB 11% (over Xmax)

60 Hz 121 dB 2%

70 Hz 121 dB 8%

80 Hz 119 dB 11% (at Xmax)

Excluding 30 & 35 Hz, an average of 8.29 % distortion.

The 6 ohm Eminence Lab 12 is rated at 400 watts, 13mm Xmax. Tests were done at 200 watts (34.6 volts) and 400 watts (49 volts), the lower trace is 200 watts.

The 50 Hz Lab 12 picture also has a third excursion figure with 655 watts (62.7 v).

30 Hz 100 dB 5% distortion (200 watt figure, 400w was missed in test)

35 Hz 105 dB 3%

40 Hz 107 dB 3%

45 Hz 112 dB 6%

50 Hz 114 dB 7% 116 dB at 655 watts 8% (over Xmax)

60 Hz 113 dB 8%

70 Hz 113 dB 4%

80 Hz 112 dB 5%

An average of 5.13 % distortion.

Phil tested the JBL SRX 718 at 85 volts (903 watts, a bit above the 800 watt rating) at 10 meters, add 20 dB for a one meter level:

45 Hz 102 dB 9%

50 Hz 106 dB 18%

55 Hz 107 dB 8%

60 Hz 111 dB 5%

70 Hz 110 dB 5%

80 Hz 109 dB 10%

An average of 9.17% distortion.

The Eminence Lab 12 has about half the distortion of the JBL SRX 718, the Eminence 4015LF has slightly less distortion than the JBL.

Both Eminence speakers showed some power compression, which would increase the percentage of distortion compared to a cool speaker.

All three speakers are remarkably low in distortion, many commonly used speakers have distortion far greater at one tenth the input power than these have at full rated power.

Art Welter