Summary - Ear Effects and Tuning Features


  • Putting an ear into the front volume of the closed backed headphone increases the low frequency efficiency.  This is due to the overall decrease in volume what was previously observed to increase SPL.
  • When the ear model was applied, the pressure sampling point was changed from a flat baffle enclosing the volume to the bottom of the ear canal that was included in the ear's geometrical definition.  As a result of this, a distinct magnification in SPL was observed at ~3kHz, and to a lesser extent 10kHz, corresponding with the ear canal resonances.  This magnification could be "tuned" in terms of damping to better correspond to experimental results of the same.
  • Short circuiting the front and rear enclosures is another degree of freedom in the design of closed backed headphones.  This had the effect of controlling the low bass by varying the amount of resistance applied to the short circuiting apertures.  This, in combination with other tuning features can be used to design the frequency response such that a known target is reached