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Joseph Crowe

3D CAD files --- ES450 Biradial for TAD TD-4002

Regular price $200.00 USD
Regular price Sale price $200.00 USD
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The horn achieves a 450Hz cutoff frequency (Fc). We recommend a crossover point in the 600Hz-800Hz region so that a standard 2nd order crossover slope can be achieved to match slopes with the low frequency driver's low pass function. 

This horn is custom designed for the TAD TD-4002 and requires the removal the stock throat adapter. This eliminates the conical throat transition and and allows an optimal throat horn flare curvature for proper exponential loading. The driver is mounted to the horn using the same holes used to mount the throat adapter. For reference, the holes are M7 x 87.5mm spacing. This unique hole pattern means the horn can only accommodate this driver.  The existing M7 hex bolts can be re-used to mount the driver to the horn. 

Please custom design please contact


  • 3D CAD files of upper and lower halves of horn (.iges and .STL format)
  • Designed for ease of CNC machine with draft angles for CNC cutter clearance 
  • 39mm (1.54") throat diameter 
  • Matched physical transition between horn and driver for smooth frequency response
  • Designed to minimize even and odd order acoustical reflections which smear time domain performance
  • Even off-axis coverage 
  • Good coverage in upper treble allow for 2-way applications 
  • Works with TAD TD-4002
  • Accommodates M7 diameter bolts x2 spaced 87.5mm apart 

Below are the files included in the zipped folder which is emailed after ordering. 

The below assembly drawing is shown as an example system comprised of the 1939 horn along with the 1838 bass cabinet which is a 200L cabinet using the Altec 416 woofer. This configuration represents a reasonable setup where the off-axis coverage is perfectly matched at the crossover point. This creates an even power response into the room. 



Below is the sectional view of the 288 compression driver (as an example) transitioning into a smooth horn flare curvature for low edge diffraction. The ES Biradial technology has virtually zero acoustical resonances which makes it devoid of any horn coloration. This unlocks the true sound quality potential of your compression driver, providing audiophile sound quality that is free from honkiness, shout, and harshness. 


Please see our guide on finding a CNC shop for local manufacture.