APL1LS – half rack unit of APL1 family


APL1LS is a FIR based 2 channel equalizer with 4096 coefficient FIR filters per channel allowing curve resolution of up to 6Hz. It is capable of creating any arbitrary Amplitude Frequency Response (AFR), Phase Frequency Response (PFR) or Delay Frequency Response (DFR) suitable for very detailed and accurate corrections and equalization in critical applications such as studio monitors, headphones and car audio systems.

USB connection allows the upload of correction filter files to APL1LS unit even in the middle of a live performance without any disturbances in sound. The unit has a 16 preset memory accessible trough a rotary switch.




  • Number of processing channels: 2
  • Resolution: 48kHz/24bits (up to 56 bit custom FPGA processing)
  • Frequency resolution of correction curve: 6 Hz, 4096 coefficients at 24 kHz bandwidth
  • Frequency response (20Hz - 20kHz) +0.0/-0.3 dB
  • Inputs: 2 analog balanced, digital - SPDIF coaxial and TOSLINK optical, AES/EBU
  • Outputs - 2 analog (XLR balanced), digital - SPDIF coaxial and TOSLINK optical, AES/EBU
  • Input/output analog signal max levels: +10dBu (can be changed on order)
  • Analog input/output connection types: XLR
  • Analog input impedance: 10 kOhm
  • Analog output impedance: 150 Ohm
  • Common mode signal rejection (CMSR) of analog input – 90 dB
  • Dynamic range (analog input/output):104 dBA.
  • THD (analog input/output): 0,07%
  • Signal delay: 1.6 ms (analog input/output), 2.4 ms (digital input/output)
  • 16 preset internal memory selectable by the rotary switch on the front panel of the unit
  • Control and upload interface: USB
  • Interface computer system: Microsoft Windows
  • Power: 6.5 to 16 V DC, 3.5 W
  • Dimensions 222x41x170 mm
  • Weight: 990 g



Images of APL1LS        Click on the image to enlarge it!