Fostex FM4 4 Channel Portbale Mixer

As a 4-channel portable audio mixer designed specifically for EFP, broadcast, on-location TV and film applications, you would expect exceptional audio performance with flexible output options and the FM-4 does not disappoint. Each of the 4 balanced XLR inputs can accept mic or line level inputs and features 12T and 48V Phantom power, an ultra-low noise pre-amp design with high quality custom transformers and switchable Hi Shelving EQ and Mid Sweep EQ. Metering is taken care of by an easy to read, highly visible organic LED display with high resolution metering offering both VU and peak level indication, battery level and selectable stereo and mono modes.

There are multiple output options including sub outputs, a Tape output and 2 x AUX outputs with channel select. The main outputs (x2) and sub outputs (x2) also double as 1-4ch Direct Out (post-fader). In addition, a dedicated monitor return input is available for referencing audio from VTR or Camera feeds.

With their low-noise circuitry, exceptional audio fidelity and unique feature sets the new Fostex Portable Mixers are not only more than suitable for all professional broadcast and film applications, they set a new benchmark for portable on-location mixing devices.

Features

• Balanced 4ch inputs (Mic/Line) and 2ch main outputs with high quality custom transformers.
• Highly visible Organic LED display with high resolution metering to offer both VU and Peak level with selectable Stereo and Mono indication.
• Mixer's parameter setting status (mic/line, phantom on/off, etc) can be seen on the display.
• Wealth of outputs such as Sub outputs, Tape output, 2 x AUX outputs with channel select.
• A dedicated monitor return input to check the audio from VTR or Camera feeds.
• Main outputs (x2) and Sub outputs (x2) double as 1-4ch Direct Out  (post-fader).
• Hi Shelving EQ and Mid Parametric EQ for ch1/3 and 2/4 selectable.
• Seamless PAN control and Fader Link function (1-2ch & 3-4ch).
• Analog limiter on Main outputs with threshold and ratio adjustments.
• Phones outs on standard and mini plugs (in parallel) from multiple source selection and PFL.
• Light but robust aluminum body construction with exclusively-machined large aluminum fader knobs.
• Metal axis fader pots using conductive plastic for higher durability.
• Master, Trim, HPF and EQ knobs with pop up mechanism to avoid inadvertent operations.
• Internal 8 x AA batteries or DC12-24V external powering.  More than 6 hours operation with alkaline batteries (phantom off).
• Switchable level settings at +4/0/ -20/ -60 on Main and Sub outputs.
• AUX input can be merged to the Stereo bus for cascade connection.
• The remaining battery capacity can be displayed on both the display and LED indicator.
• DC output with Hirose connector for powering a wireless receiver.

Specifications

Analog Inputs

• INPUT 1 through INPUT 4: XLR-3-31 type (transformer balanced)

Mic input

• Input impedance: 2 k Ohm or more
• Nominal input level: -70 dBu to -30 dBu
• Phantom Power: P48V or T12V (selectable)

Line input

• Input impedance: 10 k Ohm or more
• Nominal input level: -20 dBu to +4 dBu

Aux Input

• Input impedance: 20 k Ohm or more
• Nominal input level: +4 dBu

Rtn In

• Connector: ø3.5mm stereo mini-phone jack (unbalanced)
• Input impedance: 10 k Ohm or more
• Nominal input level: -10 dBV

Analog Outputs

Main Out (L, R) / Direct Out (CH1-2)

• XLR-3-32 type (transformer balanced)
• Applicable load impedance: 600 Ohm or more
• Nominal output level: +4, 0, -10 or -60 dBu (FM-4) / +4, 0, -20 or -60 dBu (FM-3) (switchable)

FM-4 Sub out / Direct out (CH 3-4)

• XLR-5-52 type (electronically balanced)
• Applicable load impedance: 10 k Ohm or more
• Nominal output level: +4, 0, -20 or -60 dBu (switchable)

Tape Out

• Connector: ø 3.5mm stereo mini-phone jack (unbalanced)
• Applicable load impedance: 10 k Ohm or more
• Nominal output level: -10 dBV

Aux Out

• Connector: ø3.5mm stereo mini-phone jack (unbalanced)
• Applicable load impedance: 10 k Ohm or more
• Nominal output level: -10 dBV or -60 dBV (switchable)

Phones

• Connectors : 1/4” stereo phone jack and ø3.5mm stereo mini-phone jack
• Applicable load impedance: 8 Ohm or more

Limiter

• Attack time: approx 5 msec. Release time: approx 200 msec.
• Threshold level: +6, +9 or +12dBu (FM-4) / +6 or +12dBu (FM-3) output level
• Ratio: 3:1 or 5:1 (level and ratio can be selected using the status mode)
• DC IN: XLR-4-32 type (male). Input voltage: DC10V to DC 24V
• DC OUT: Hirose 4 pin (female). Applicable plug: Hirose HR10A-7P-4P. DC7.2V - 24

Performance

Frequency response

• LINE IN - MAIN OUT: 20Hz to 20kHz +/- 1dB (reference level)
• MIC IN - MAIN OUT: 40Hz to 20kHz +/- 1dB (reference level)
• HEADPHONES (32 Ohm load, 25mW output power): 20Hz to 20kHz +/- 3dB

S/N ratio (A-weighted)

• LINE (INPUT GAIN: +4 dBu): 80dB or better
• MIC (INPUT GAIN: -70dBu: 55dB or better (equivalent input noise: -125 dBu)

Total harmonic distortion:

• LINE: 0.1% or less at 1 kHz (Input Gain +4dBu)
• MIC: 0.1% or less at 1kHz (Input Gain -70dBu)

• Headphones residual noise: (PHONES level control at minimum) -72 dBV or less (A-weighted)
• Crosstalk: -70 dB or less at 1kHz
• HPF: 40Hz to 200Hz, -12dB/oct. The cutoff frequency is continuously sweepable.
• EQ: HI: 10kHz fixed, +/-12dB MID: 200-8kHz variable, +/-12dB

Physical

• External dimensions: 274 (W) x 57 (H) x 180 (D) mm (Including protrusions)
• Weight: Approximately 1.5kg (not including the internal batteries)  
• Internal batteries: Eight AA batteries (alkaline: 12V, nickel hydride: 9.6V)
• Power requirement: DC7.2 to 12V
• External power supply: Optional AC adaptor (AD15C / AD15-4300)