Full CAD/CAM plans for ES-290 Biradial Horn -- 1.50" Throat

Sale price Price $285.00 Regular price

By purchasing these plans you'll automatically receive the 3D CAD files and CNC program to make the ES-290 Biradial Horn.  


  • 3D CAD Files for horn assembly and CNC nested layout (.iges file format) 
  • CNC program files (.nc format) using standard G-Code 
  • CNC Setup Sheet and Instructions 

ES-290 Biradial Technology 

The ES-290 is an exclusive product from Joseph Crowe which utilizes modern horn theory to produce a world class sounding horn for audiophile applications.  The ES horn flare curvature virtually eliminates any reflections or resonances in the horn throat and off the horn mouth.  By gently allowing the acoustical wave front to propagate away from the horn with no physically abrupt edges any edge diffraction is eliminated resulting in a very clean step response, burst decay, frequency response, and off-axis response.  


  • Low frequency cut-off 290Hz
  • Throat diameter 1.50" 
  • Throat Exit Half Angle: 3.8 degrees 
  • Overal Physical Size:  642mm Wide x 300mm High x 335mm Deep (25.26" x 11.81" x 13.20") 
  • Driver Mounting Hole Pattern:  Two holes 4.00" apart using 1/4" diameter threaded studs with nuts. 


The ES-290 Biradial is designed for applications that demand the highest sound quality possible such as recording studios and audiophile systems.  The biradial shape allows closer driver spacing to the low frequency driver and helps reduce first order reflections such as those found with circular horns.  

ES Curvature 

The ES Curvature (Exponential Spiral) is an algorithm found in nature (ie. Logarithmic Spiral) and has been found to perform exceptionally well in acoustical applications.   Joseph Crowe has adapted this geometry into a biradial format...a first for any horn technology.   

DIY and Commercial Licencing 

The technology included in this package is for DIY use only.  Commercial reproduction is strictly prohibited however special licencing agreements can be accommodated.  Please contact for more information. 

What's Provided 

Once purchased you be provided with the CNC G-Code files.  The G-Code files are text based files that are loaded into a CNC machine to instruct the CNC machine on the required cutter path.   Most CNC machines accept what is known as 'ISO G-Code' which is a standard text based language that is read by the CNC machine's control software.  This is often the technical hurdle that many face when attempting to CNC machine components.  Joseph Crowe has done the hard part by completing all of the CNC programming for you.  

Typical Workflow to build your horns...

Typically you would contact your local shop and inquire about having the horns built.  You would inform the shop that you already have the 3D CAD files and CAM programming already completed in G-Code format.  Many shops would welcome the fact that you already have the G-Code completed.  Simply email the zipped files to the shop and allow them to quote you on manufacturing the horns for you.  You will want to look up your local kitchen cabinet shops or sign shops to see if they are willing to quote.