Archive for: ‘January 2015’

ScanSpeak 18W/4531 Measurements!

January 25, 2015 Posted by gornir


This time on the test bench we have the ScanSpeak 18W/4531 mid-woofer from the ”Revelator” series.

The two tested driver units are the 18W/4531-00 and the 18W/4531-01.

Measurement details for the two different mid-woofer versions can be found here:




(click on picture to zoom)

Left: 18W/4531-00

Right: 18W/4531-01

What’s the difference between the -00 and the -01 version?


These two mid-woofers are very similar and the main difference is the cone material used. The -00 version uses a sliced paper cone and where the slices are filled with damping glue. The -01 version uses a similar sliced paper cone, but the paper cone is also mixed with wood fibers, hence the slightly grayer color of the cone.

Both versions have a 38mm voice-coil, but the -01 version has a slightly taller (0.5mm) voice-coil compared to the -00 version. In all other aspects e.g. magnet size etc. they are identical and even though the official specification indicates that the -01 version has a slightly larger cone area of the two (157cm2 v.s. 150cm2), it has the same cone area as the -00 version.




18W4531G Imp 00 vs 01

(click on picture to zoom)

Blue: 18W/4531-00

Green: 18W/4531-01

The impedance wrinkle around 800Hz is a bit more pronounced for the -01 version compared to the -00 version. Besides that the impedance plot is virtually identical between the two versions.




18W4531G Freq 0deg 00 vs 0118W4531G Freq 15deg 00 vs 01

(click on picture to zoom)

Left: Frequency response on-axis (Blue= -00 version, Red= -01 version).
Right: Frequency response 15deg off-axis (Blue= -00 version, Red= -01 version).

Both versions have an extended frequency response and a very smooth frequency roll-off without any nasty cone break-ups.

The -00 version has a smoother frequency response around 800Hz (where the impedance wrinkle is) compared to the -01 version. It also has a slightly more extended frequency response.

The -01 version on the other hand has a slightly smoother frequency response in the 2-6kHz range compared to the -00 version.

They are both outstanding frequency response performers compared to just about any 7” mid-woofers in the market.




18W4531G-00_56880-29-2R--15cm 95db18W4531G-01_58032-15-2R--15cm 95db

(click on picture to zoom)

Left: 18W/4531-00

Right: 18W/4531-01

Both versions have a very low odd-order distortion profile, but both also have an elevated second-order distortion profile in the 0,4-1,2kHz area.



Both the -00 and the -01 version are top performers and any of them can be chosen from a performance perspective. Most likely they can also be a drop in replacement to each other in many designs and it’s more a matter of price and availability, which one to choose. I personally think the less common -01 version with its wood fiber cone looks interesting.