Tests of Viawave GRT-145W-8
Copyright 2019 © Troels Gravesen

Opening the Viawave GRT-145W-8 box immediately oozes quality. The 110 mm large and 8.5 mm thick aluminum face-plate/waveguide and the weight of 1.4 kgs each adds to this impression.
This is a ribbon tweeter similar to the one tested a couple of years ago: http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm, only this one is fitted with a short waveguide increasing response towards lower frequencies allowing a wider operating range and easier implementation.
Nothing surprised me during the test cycle. Everything as expected and in accordance with the data promised in the data sheet.
I can't wait implementing these drivers in future construction.

Download spec here: GRT-145W-8

Click images to view large.

SPL of two ribbons measured at 0.5 m distance normalised for 2.8V/1 meter.
Ribbons flush mounted on 80 x 100 cm baffle.

Impedance of driver.

Step response.

Horizontal dispersion at 0, 10, 20, 30 and 40 deg. off-axis.

Vertical dispersion measured at 0, 10, 20 and 30 deg. off-axis.

DISTORTION 

Unit #1: Distortion measured with signal equivalent for 99 dB/1 meter.

Unit #1: Distortion measured with signal equivalent for 93 dB/1 meter.

Unit #1: Distortion measured with signal equivalent for 87 dB/1 meter.

Unit #1: Distortion measured with signal equivalent for 81 dB/1 meter.

Unit #2: Distortion measured with signal equivalent for 99 dB/1 meter.

Unit #2: Distortion measured with signal equivalent for 93 dB/1 meter.

Unit #2: Distortion measured with signal equivalent for 87 dB/1 meter.

Unit #2: Distortion measured with signal equivalent for 81 dB/1 meter.

Unit #1: 2nd harm. distortion @ four levels.
A bit unusual to see higher levels of distortion at lower levels, but this is below 2 kHz, so nothing that worries me.

Unit #2: 2nd harm. distortion @ four levels.

CSD with 25 dB scaling.

CSD with 35 dB scaling.