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Joseph Crowe

Horn Lens No.2474 for Fostex T90A

$680.00 CAD
$680.00 CAD
Sale Sold out

Introduction 

Horn lens No.2474 is an assembly designed to replace the existing front half of the Fostex T90A tweeter. The horn lens alters the horn flare geometry to alter the sound quality. 

Sound Character Changes

  1. The 2474 lens improves soundstage depth at the expense of soundstage width. Other attributes are improved overall clarity, detail, and smoothness. 
  2. Steeper slope at Fc which simplifies the passive high pass filter (LR4 reduced to LR2 or first order electric slope) This reduces the number of components in the signal path. 
  3. 2.5dB higher sensitivity 

Horn Lens Assembly No.2474 includes:

  • 2258 Wood Horn Lens (Can also be used with Fostex T900A)
  • 3D Printed clamp bracket No.2474-01-002 
  • M4 screws x3 with nylock nuts 
  • Solid walnut 
  • x2 coats of wax 
  • Sold individually 
  • Select x2 at checkout for one pair 

Technical drawing click HERE.

For comparison test data click HERE.

 

Belo
Below is the stock frequency response (red) with the 2474 response (blue) both using a 3.3uF capacitor. The 2474 horn lens provides a textbook slope for easier integration with the midrange horn. Slope symmetry is maintained which provides improved soundstage depth and coherency. The smoother response indicates less coloration and diffraction artifacts in the time domain. 
Below is the stock CSD plot for the T90A tweeter.
Below is the CSD plot for the 2474/T90A combo.