Features

Overview: The JBL CSM 28 is an 8-channel mixer capable of a wide range of applications, such as background music, security, and paging for commercial installations ranging from schools and hospitals to restaurants and fitness centers. It features 8 input channels and 2 outputs for passing audio signals to an outboard amplifier (sold separately).

Inputs: All of the CSM 28's eight input channels features a Euroblock connector that can accept either Line- or Mic-level signals. Inputs 2, 3, 4, 6, 7, and 8 include a pair of RCA jacks for running consumer-level audio signals, such as a CD or media player. Inputs1 & 5 include connections for a paging microphone along with an audio source. Each input includes a 2-way switch for selecting the signal type with selections for either Mic or Line.

Output: Two 3-pin Euroblock connectors provide a Line Level output signal, up to 5.0Vrms, for running to an outboard amplifier or set of powered speakers.

VOX Function: Voice-activated ducking, or the VOX function, is available on input channels 1 & 5. This function causes attenuation of the overall output level of the amplifier when the input level on channel 1 or 5 reaches a set threshold. A designated VOX trim pot is provided for setting the audio input level required to activate ducking. Typical usage of the VOX function is to automatically lower the background music in a room while making announcements over the audio system. After the announcement is made, the background music returns to its previously set level.

DIP Switches: Two 6-switch DIP panels let you easily make input/output assignments along with activating phantom power and high-pass filtering.

• Matrix: Eight DIP switches can be used to route each of the 8 inputs to either of the 2 outputs.
• Phantom Power: A single DIP switch lets you apply +27VDC of phantom power to all of the inputs when using condenser microphones requiring external power.
• High-Pass Filter: Two DIP switches let you apply a 70Hz high-pass filter to input channels 1-4 and 5-8.

Bass/Treble: Two recessed front-panel dials can provide +/- 10dB of adjustment @ 100Hz and 10kHz for the output signal.

Signal&Clip Indication: Each of the 8 input channels has its own front-panel Level Control with an illuminated ring around each. The rings will light Green when signal is present and will change to Red when the signal has reached the threshold of audible distortion (clipping). The Power button also has an illuminated ring that lights Green when the unit is in standby and Blue when in a normal operating mode.

CSR-V Remote Volume: Two rear-panel RJ-45 jacks are provided for connecting optional CSR-V remote volume controls (sold separately) - one for each output channel. The remotes get wired to the mixer with CAT-5 cable (sold separately) and allow you to remotely select the source and control the volume on the mixer from up to 1000 feet away. The CSR-V is available in black or white.

Mounting: The CSM 28 can used in a table- or shelf-mount orientation with 4 rubber stick-on feet provided. Rack-ears and mounting hardware are provided for mounting the mixer in a standard 19" equipment rack.

Specifications:

• Input Channels: 8 (8 Euroblock & 6 pairs of RCAs)
• Input Sensitivity (for a 5V output):
  • Mic: 3mVrms
  • Line: 775mVrms
  • RCA: 300mVrms
• Output Channels: 2 (3-pin Euroblock)
• Output Level (Line): 5.0Vrms into a 10kΩ load
• Frequency Response: 20Hz - 20kHz (+/- 1dB)
• THD: 0.05% Typical
• S/N Ratio: >90dB
• Input Impedance:
  • Mic: 400 ohm
  • Line: 20 kilo-ohm
  • RCA: 50 kilo-ohm
• Phantom Power: +27VDC
• Crosstalk: >70dB
• Tone Controls:
  • Bass: +/- 10dB @ 100Hz
  • Treble: +/- 10dB @ 10kHz
• Nominal AC Line Voltages: 100V - 240V, 50/60Hz
• Dimensions: Width = 17.188" (19" w/ rack-ears), Height = 1.75", Depth = 15.375" (incl. power cord)
• Net Weight: 7.5 lbs.