The PT2522 is a high Quality speaker chassis at a modest price of around 50 € per piece currently. To preserve maximum flexibility, it however comes without a front plate which is required as a mounting frame. Moreover, when used as replacement a custimized front plate is necessary to match the dimensions of the old speaker chassis.

Planar tweetersare known to exhibit a very narrow listening sweet spot in the perpendicular position to the listener that can be improved by a waveguide. My design therefore includes a basic waveguide that is inspired by measurements found on the web. Note: I have no means of measuring the frequency behavior myself.

The included STL-file can be used to replace old tweeters from a BRAUN M90 speaker with the GRS PT2522-4 (adjustments to the cross over are necessary to adjust for the typical high efficiency of planar speakers, you can consult a large language model of your choice to get help if required).

The Open Scad file can be used to adjust the face plate design to basically any other replacement situation.

Printed in PLA-CF, no support necessary. Two walls, 15% infill.