Midrange test data

The following midranges were tested--

    Seas W15

    Seas M15

    Seas MCA15

    Focal 5W

    GR Research M130

The following data are shown

Impedance-standard curves and enlarged views

Nearfield frequency response, done at 1"

Nearfield linear burst distortion at 600 hz, 1k, 1.4k, 1.8k

Nonlinear distortion at 0.25m-triplets centered at 150 hz, 400hz, and 850 hz.

Impedance data

From 20 Hz to 10k

A closer look at the region from 100 to 5k.

Frequency response

Linear distortion

Nonlinear distortion data

At 150 Hz

At 400 Hz

At 850 Hz

Comments

I'm not going to tell you exactly which is best.  It depends on your application. The M15 and MCA15 are pure mids and struggle with nonlinear distortion at 150 Hz. On the other hand, they have good nonlinear distortion at 400 and 850 Hz, and have the smoothest FR/best linear distortion numbers above 1k. As a pure mid, the MCA15 is probably the best value. The M15 may be marginally better, but not by much and is very expensive.  The W15, RS150, and 5W are more midwoofers. In terms of nonlinear distortion, I think overall the rankings would be W15, RS150, M130, and 5W. The W15 also has very good linear distortion/FR up to 1400. Crossed low, the W15 would be an excellent driver.

Let me say, though, that NONE of these drivers really does an adequate job reproducing low bass. While the W15 nonlinear plot looks great above, increasing the drive level just one more dB caused the driver to start audibly distorting with some rub/buzz type noise. While the W15 would be great in a 2 way at low volumes, you're kidding yourself that you can get any realistic bass output out of it. Likely you'll just be faked out by the 2nd and 3rd order products as you increase the volume.