Audiopulse

Performance Parameters

• BL²/Re
  Most manufactures will not spec this number, however we feel it inappropriate to omit it.
   
  BL is the actual cross product of the magnet field B with the conductor length L. It is not a scalar, but rather a vector. Combine this vector with the current I and you’ll get exactly the force (up or down according to the DC or AC input). But with the way amplifiers are designed, the current I of the speaker is never constant, only the voltage is. It is also not entirely important to know what the force is because is changes so rapidly. In any event, the BL squared divided by the resistance of the voice coil Re in fact gives us a generic force factor in newtons squared per watt. This number is relative for all speakers and the higher the number, the more force a motor can invoke on a cone with the same input power.
   
  Its important to distinguish that BL and Re are related much like inductance and Re are. 32Tm over 8 ohms is identical to 16Tm over 2 ohms, namely 128 N²/W. All other things equal (moving mass and cone size in particualr), A higher BL²/Re will increase the sensitivity of the driver which is a generally a very good thing.
• TLS
  An Audiopulse exclusive parameter which goes beyond the diluted “xmax” standard. We define TLS to be the one way total linear stroke of less than 1% BL deviation. That is the threshold of virtually zero non-linear BL distortion. This parameter is often extremely low among the vast majority of drivers and it is important to know that a high TLS usually yields a very low distortion driver.

Theile Small Parameters

• BL
  The cross product of the magnetic gauss in the gap ‘B’ with the effective conductor length ‘L’. BL is measured in Tesla meters or Newtons per Ampere (same units)
• Cab
  Compliance of the driver inside the box.
• Cas
  Compliance (1/stiffness) of the driver’s suspension system measured in (same as Cms).
• Cms
  Compliance (1/stiffness) of the driver’s suspension system (same as Cas).
• Fc
  Resonance frequency of the driver in a closed box system.
• Fs
  Resonance frequency of the driver in free air.
• Lp
  Inductance in a parallel circuit model with the Rp resistor
• Ls
  Inductance in a series circuit model with the Rp resistor
• Q
  Ratio of reactance to resistance or vice versa. This terms can apply to mechanical, electrical or even pneumatics’s models. Its often used to describe drivers (Qts), filters or entire systems (Qb).
• Qes
  The Q of the driver at Fs as a function of electromotive damping factor.
• Qms
  The Q of the driver at Fs as a function of the mechanical damping factor.
• Qts
  The combine factor of Qes and Qms of the driver.
• Rp
  Resistor used in the inductance circuit model with either Ls or Lp
• Sd
  The effective surface area of the driver’s cone.
• Vab
  The volume of air which has the same compliance as driver inside an enclosure.
• Vas
  The volume of air which has the same compliance as the drivers suspension in free air.
• Vb
  Net volume of an enclosure.
• Vd
  Maximum linear displacement that the driver can do.