Skip to product information
1 of 25

Joseph Crowe

3D CAD Model for Horn No.1155 —- Biradial for RAAL 7020XR

Regular price $30.00 CAD
Regular price Sale price $30.00 CAD
Sale Sold out
This product is the 3D CAD model of the No.1155 biradial horn for the RAAL 70-20XR true ribbon tweeter.  Once you complete the transaction on this product page you will automatically receive the 3D CAD Files via email as a zipped file.  This includes the adapter plate that mounts the driver and also provides a smooth throat transition for proper horn loading.  Please note this 3D CAD model is for personal use only.  For commercial licencing please inquire.  
The 1155 horn is a special horn designed to work with pure ribbon tweeters.   The 1155 Horn can be customized for other ribbon type tweeters including planar.  
Technical Drawing click HERE.
The original blog post featuring the first project can be found HERE


  • Funds in CAD Currency 
  • Plastic throat adapter to ensure smooth horn flare transition 
  • 1.2kHz Fc 
  • 3D CAD Files can used  for 3D printing or CNC Machining 
  • Support stand and rear foam

    Acoustical Measurements 

    The below measurement is a comparison between the 1155 Horn (Green) and the driver mounted to a regular speaker baffle (Red).  

    Off-Axis Performance 

    The 1155 horn drastically improves the off-axis performance providing much wider coverage in the upper treble and also controlling the coverage in the midrange so that it matches the power response into the room.  This drastically improves the natural sound of instruments giving them better musical timbrel accuracy.  Edge diffraction is completely eliminated with the 1155 horn which improves transient detail.  

    How it’s made video click here.