Calculate Closed Enclosure (choose Qtc)

After figuring out which Qtc you want to hit for, you can find out the volume of the box. Take into consideration that after you calculated the net volume of the box, you should add the volume dislocated by the back of the driver (magnet assembly) , crossovers, bracing etc, so you get the gross volume of the box.
Also, if you add stuffing, this will effectively increase the volume of the box, so keep that in mind also.

  Fs :    Hz - Resonant frequency of the driver  
  Qts :    Total Q of the driver  
  Qes :    Electrical Q of the driver  
  Vas :    Liters - Volume of air with same compliance  
  Qtc :    total Q of the speaker in an enclosure including all system resistances.  

You can change the Qtc value and other TSP Parameters


  • EBP < 50 - use only for a sealed box
  • EBP 50 - 100 - can be used in either
  • EBP > 100 - vented box only
  • EBP > 130 - can be used for Horn Loudspeakers
  EBP :    
  Vb :  Liters - Net volume in liters of the box ( No filling with absorbent material ! )  
  Fc [Hz] :  Hz - Resonant frequency of the chassis in the housing  
  F3 [Hz] :  Hz - Frequency where the level has dropped by 3 dB  
  Fmax [Hz] :  Hz - maximum amplitude peak at Fmax (for QTc > 0.71)  
  Amax [dB] :  dB - Frequency of maximum amplitude enhancement (for Qtc > 0.71)  

  • Move the mouse over the Plot Line and you will see the Frequency and dB values at that position.
  • You can zoom in by selecting a range with the mouse.

Frequency Response

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