Pioneer PD-200S on ES800 Biradial

Pioneer PD-200S on Horn No.1603 (ES-800 Biradial) 

In this blog post I feature a recent build for a customer who commissioned me to build a Biradial horn for his vintage Pioneer PD-200S compression drivers. 

Driver Features 

  • Circa.1974 (almost 50 years old) 
  • Highest class series for Pioneer at the time 
  • Pioneer referred to it as the “Super Sound Series”
  • 500Hz-13kHz 
  • 34mm Diameter External Thread (1.5mm pitch) 
  • 19mm Throat Diameter 
  • 16ohm 

Horn No.1603 Features 

  • 800Hz Fc
  • Cherry hardwood 
  • Throat adapter (19mm to 25.4mm)
  • Driver cradle 
  • Side mounted Autoformer with NL4 connector
  • Rubber feet 

Impedance Sweep (see below)

  • FS at 480Hz.  
  • 16ohm at 3kHz.  
  • Resonance at 1100Hz which we can see in future graphs. 
  • Diaphragm breakup occurs starting at 11kHz.

Frequency Response

Shown below, we see the resonant peak coming in at 1100Hz. This is followed by a -4dB drop at 2.5kHz. The response then slowly and gently rises to 11kHz where is falls off sharply at the diaphragm breakup mode. 

Burst Decay 



Harmonic Distortion 

I set the test tone to 90dB SPL at 1 meter and measured the harmonic distortion. 2nd order is -45dB down at 2kHz along with 3rd at -56dB, and 4th at -70dB.  The distortion profile across the frequency spectrum is relatively consistent. 


Environmental Noise is shown below for Reference. I set the 12 bad per octave multitone test signal to 90dB and monitored the noise spectra generated by the driver. We see IMD products -50dB down at 2kHz increasing to -42dB at 10kHz. Adding a 4kHz 4th order high pass filter sees this figure improve to -60dB at 10kHz. 

The customer has indicated that these drivers hold sentimental value. Mounting them to the ES-800 Biradial means musical enjoyment for many more years to come. 



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