Dimensions

• The Alpine CDA-9857 is a standard DIN-sized head unit. Width measures 7 inches, with depth and height at 6.4 and 2 inches, respectively. Weight is a standard 3.5 pounds.
  
  

Power Ratings

• The 9857's internal amplifier is rated at 50 watts maximum. Continuous power is rated at 18 watts per channel at 4 ohms, with a nominal distortion rating of 1 percent.
  
  

Equalization and Tone Controls

• Sound customization is achieved via a 2-band parametric equalizer. Center frequencies for this equalizer are at 60, 80, 100, 120 hertz for bass. Midrange frequencies offer adjustment at 7,500 and 10,000 hertz. Treble is fine-tuned by using frequency adjustments at 12,500 and 15,000 hertz. The CDA-9857 is equipped with standard bass and treble controls as well.
  
  

Special Processing and Features

• The Alpine head unit is equipped with Barcus-Berry Electronics (BBE) sonic restoration. Increasingly important with the prevalence of compressed audio formats, BBE attempts to restore the dynamics and clarity found in sources that are less compressed. Additionally, the 9857 is HD radio-ready, meaning that a standard car antenna connection allows access to clearer FM and AM sound.