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Joseph Crowe

3D CAD Model -- RCF ND850 Rear Cover No.2089-02

Regular price $30.00 USD
Regular price Sale price $30.00 USD
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By purchasing these plans you will automatically receive the 3D CAD File via email to 3D print the rear cover. 


This rear cover replaces the existing rear cover on the RCF ND850 compression driver. The purpose of the cover is to enlarge the rear air volume thereby lowering the driver's fundamental resonance. This reduces the driver's maximum power handling capacity but extends the lower frequency bandwidth for home use. Distortion is lowered as well when operating at output levels below 105dB at 1m, (well below typical listening levels for concert PA applications). 

For full technical details visit the related blog post HERE


Simply remove the existing cover and re-install the new 3D printed cover using the existing screws.  Fasten the screws thumb tight and then tighten each screw 1/4 turn each until snug. Do not over-tighten. 


No damping is required, although you can experiment with automotive undelay glued to the rear wall of the chamber. Do no allow the damping material to touch the diaphragm. 


Files are provided in .STL and .iges format 


Please contact for custom design work.

3D Printing 

We offer 3D printing services as well as custom CNC machining in various hardwoods, plastics, and soft metals. Please contact for a quote.