ART USBMIX4 Project Series User's Manual
FOUR CHANNEL MIXER WITH USB INTERFACE
Important Safety Instructions
[Warning Symbol] This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltages inside the enclosure that may be sufficient to constitute a risk of shock.
[Alert Symbol] This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the accompanying literature. Please read the manual.
Read Instructions
Retain these safety and operating instructions for future reference. Heed all warnings printed here and on the equipment. Follow the operating instructions printed in this user guide.
Do Not Open
There are no user serviceable parts inside. Refer any service work to qualified technical personnel only.
Power Sources
Only connect the unit to mains power of the type described in this user guide or marked on the rear panel. The power source must provide a good ground connection.
Power Supply
Use the external power supply for your local mains supply as provided with the equipment. If the provided external supply does not fit into your outlet, consult your service agent. Route the external power cord so that it is not likely to be walked on, stretched, or pinched by items placed upon or against it.
Grounding
Do not defeat the grounding and polarization means of the external power supply.
Moisture
To reduce the risk of fire or electrical shock, do not expose the unit to rain, moisture, or use in damp or wet conditions. Do not place containers of liquid on it, which may spill into any openings.
Heat
Do not locate the unit in a place close to excessive heat or direct sunlight, as this could be a fire hazard. Locate the unit away from any equipment that produces heat, such as power supplies, power amplifiers, and heaters.
Environment
Protect from excessive dirt, dust, heat, and vibration when operating and storing. Avoid tobacco ash, drink spillage, and smoke, especially that associated with smoke machines.
Handling
Protect the controls from damage during transit. Use adequate padding if you need to ship the unit. To avoid injury to yourself or damage to the equipment, take care when lifting, moving, or carrying the unit.
Servicing
Switch off the equipment and unplug the power cord immediately if it is exposed to moisture, spilled liquid, or if the power cord or plug becomes damaged during a lightning storm, or if smoke odor or noise is noted. Refer servicing to qualified technical personnel only.
Installation
Install the unit in accordance with the instructions printed in the user manual.
Introduction
The ART USBMIX4 Microphone, Instrument, and Line Mixer/Computer Interface is a compact, versatile audio interface for your computer that converts analog signals from a variety of audio sources to a digital signal that your computer recognizes. It can also be used as a stand-alone mixer through the main mix outputs. The USBMIX4 provides a great starting point for personal home studio recording or for anyone who wants to do mobile location recording. Use the USBMIX4 to record podcasts, capture your latest idea for a song, make voiceovers for your home movies, or record a jam with a friend – whenever and wherever your creativity takes you!
Features
- Powered by USB from your computer or via USB power adapter (included).
- CH1 and CH2 Microphone (balanced XLR) inputs or instrument (unbalanced 1/4-inch TS) inputs with switchable impedances.
- Switchable low noise +48V phantom power for microphones.
- Balanced 1/4-inch TRS inputs for stereo or mono line-level sources on CH3.
- 1/4-inch TRS output jacks work with balanced or unbalanced lines.
- 1/8-inch TRS stereo Aux/MP3 input.
- Stereo output, independent from the PC interface switch.
- Stereo 1/4-inch TRS headphone jack with independent level control for output monitoring.
- Independent controls for both sets of inputs, main output, and headphone monitor.
- Red LED signal/clip indicator for Ch1-2.
- No special drivers are needed with most modern versions of Windows, Mac OS, and Linux.
- USB cable, USB power adapter, and Audacity recording software included.
- Rugged steel chassis.
Installation
Prior to power up or power down, the output controls PHONES MONITOR and MAIN MIX should be turned back to "0".
- As audio sources, microphones and/or audio sources with line signal level (e.g., effect units, musical instruments, players) can be connected to the four input channels.
- Mono channels CH1 and CH2: Combined XLR/1/4-inch jack are available as inputs.
- Connect microphones to the balanced XLR jack.
- For phantom-powered microphones, engage the 48V phantom power switch for the CH-1 XLR jack. When the switch is engaged (switch position [ON] = ON), the Phantom power LED is illuminated to indicate that phantom power is being used.
- Caution! Do not connect a microphone with an unbalanced output via an XLR plug; it may be damaged by the phantom power function. To prevent switching noise, only activate or deactivate the phantom power when the mixer is switched off or the output controls are set to "0".
- Connect mono sources with line level to the unbalanced 1/4-inch jacks. It is also possible to directly connect musical instruments of high impedances (electric guitar, electric bass) to Stereo channels CH3/4.
- Stereo sources with a line level may be connected to the 1/4-inch jack of channel CH3/4 (L=left channel, R=right channel). The jacks of channel CH3/4 are balanced; however, it is also possible to connect units with unbalanced output via two-pole plugs. For connecting a mono unit to channel CH3/4, use the Left jack only. The mono signal is internally sent to the left channel and the right channel.
- Connect stereo headphones (impedance 8 ohms) to the 1/4-inch jack PHONES MONITOR or the 1/8-inch jack HEADSET [headphones] output jack.
- The sum signal adjusted with the control MAIN MIX is present at the stereo output MAIN MIX OUT.
- An amplifier or a second mixer may be connected. The 1/4-inch jacks are unbalanced.
- To switch on the mixer, set the POWER switch to position ON. The power indication POWER lights up.
Controls and Indicators
The front panel of the ART USBMIX4 features various controls and indicators for managing audio input, output, and overall mixing. Key components include:
- Input Channels (CH1, CH2, CH3-CH4): Dedicated sections for each input channel with controls for GAIN, EQ (HIGH/LOW), PAN, and LEVEL.
- Input Jacks: Combo XLR/1/4-inch jacks for CH1 and CH2, and 1/4-inch jacks for CH3-CH4.
- Phantom Power (+48V): Switchable +48V phantom power for CH1 XLR input. A corresponding LED indicates when phantom power is active.
- PAD Switches: Attenuate input signal for CH1 and CH2 to prevent distortion.
- INST-HI-Z Switch: For CH2, allows connection of high-impedance instruments like electric guitars or basses.
- POWER Switch: Turns the unit on/off. A POWER LED indicates the power status.
- RECORD SOURCE Switch: Selects the audio routing to the computer (DRY CH1-2, INPUT MIX, LOOPBACK).
- MONITOR MUTE Switch: Mutes channels 1 and 2 from main outputs and headphone outputs.
- LEVEL Controls: For CH1, CH2, CH3-CH4, COMPUTER, PHONES MONITOR, and MAIN MIX.
- PHONES MONITOR Output: 1/4-inch jack for connecting headphones.
- MAIN MIX Output: 1/4-inch jacks for main stereo output.
- STEREO OUT: Additional stereo output.
- AUX-MP3 IN: 1/8-inch stereo auxiliary input.
- USB TO PC: USB Type B port for computer connection.
- 5V DC IN: Micro USB port for external power.
- USB Recording Level Meter: LEDs indicating audio levels sent to the computer.
Operation with a Computer
- When operating the mixer with a computer, use audio software supplied with the operating system or install additional software. Various programs for audio reproduction/recording are available on the Internet free of charge.
- Boot up the computer and connect the USB jack to a USB port on the computer via the provided USB cable. The USB interface of the mixer is recognized by the computer as an external unit for audio input and audio output, often as "USB Audio CODEC". Required drivers (standard drivers of the operating system) are usually available on the computer.
- Note: If not all required drivers are available on the computer, install them, for example, via the original CD of the operating system. If necessary, restart the computer after installation.
- Activate the audio program used and make the necessary adjustments for audio reproduction via the mixer or audio recording from the mixer.
- If no audio recording or reproduction is possible, check the system settings of the computer to ensure the USB interface has been selected for audio input or output.
- Hint: If the mixer is connected both to a computer and to other units that are earth-grounded via their mains cables (e.g., amplifiers), ground loops may occur due to hum interference. To eliminate them, the mixer can be connected to the respective unit via a ground isolator.
Mixing Audio Sources
The following steps serve as a guide for basic setup; other methods are also possible.
Basic Setting First:
- Set all GAIN, EQ, and PAN controls to the mid-position.
- Turn all LEVEL controls back to the left stop.
- To adjust a mono channel to an optimum level, feed an audio signal to the channel and turn up its LEVEL control approximately to mid-position. Adjust the GAIN control of the channel so that the clip light activates on peak levels. Then adjust the sound with the EQ controls: HIGH for high frequencies, LOW for bass frequencies. As sound adjustments affect the channel level, readjust the GAIN adjustment if necessary.
- Turn the LEVEL control back to the stop and make the same adjustments for the second mono channel.
- For sound adjustment of a stereo channel, turn the LEVEL controls of the remaining channels back to the stop and turn up the LEVEL control of the stereo channel so that the sound can be optimized.
- For the mono channels, place the mono signals in the stereo field using the PAN controls.
- Adjust the desired overall volume with the MAIN MIX control. However, if the output level of the mixer is too high for the following unit, the sum signal must be adjusted to a correspondingly lower level.
Applications
This compact 4-channel audio mixer with USB interface is suited for universal applications, e.g., for audio recording on the computer. The mono input channel allows connecting a (phantom-powered) microphone; the stereo input channel allows connecting an audio source with line signal level. In addition, the mixer is provided with connections for a recorder and headphones. The mixed signal is sent to the output via 1/4-inch jacks and the USB port. It is also possible to use the USB port as an input to transfer audio data from the computer to the mixer. When connecting the mixer to a computer, power is supplied via the USB connection. When operating the mixer without a computer, use a suitable power supply unit with USB connection to operate the mixer.
Warranty Information
Limited Warranty
Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants: Applied Research and Technology (ART) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of three years from the date of purchase. Applied Research and Technology will, without charge, repair or replace, at its option, defective product or component parts upon prepaid delivery to the factory service department or authorized service center, accompanied by proof of purchase date in the form of a valid sales receipt.
Exclusions
This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs. This warranty is void if the serial number is altered, defaced, or removed. ART reserves the right to make changes in design or make additions to or improvements upon this product without any obligation to install the same on products previously manufactured. ART shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitations of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific rights and you may have other rights, which vary from state to state. For units purchased outside the United States, an authorized distributor of Applied Research and Technology will provide service.
Service
The following information is provided in the unlikely event that your unit requires service.
- Be sure that the unit is the cause of the problem. Check to make sure the unit has power, all cables are connected correctly, and the cables themselves are in working condition. You may want to consult with your dealer for assistance in troubleshooting or testing your particular configuration.
- If you believe that the ART unit is at fault, go to www.artproaudio.com.
- Select "Support", then "Return Authorization Request" to request a return authorization number.
- If you are returning the unit for service, pack the unit in its original carton or a reasonable substitute. The original packaging may not be suitable as a shipping carton, so consider putting the packaged unit in another box for shipping. Print the RA number clearly on the outside of the shipping box. Print your return shipping address on the outside of the box.
- Include, with your unit, a note with the RA number and your contact information, including a return shipping address (we cannot ship to a P.O. box) and a daytime phone number, and a description of the problem, preferably attached to the top of the unit. Also include a copy of your purchase receipt.
Please fill in the following information for your reference:
Date of purchase: ___________________________________________
Purchased from: ___________________________________________
Serial Number: ___________________________________________
Specifications
| Parameter | Details |
|---|---|
| Input Connections | XLR balanced / 1/4-inch balanced “Combo” jack (Ch1 input) XLR balanced / 1/4-inch unbalanced “Combo” jack (Ch2 input) 1/4-inch balanced or unbalanced (Ch3-Ch4 inputs) 1/8-inch (Aux/MP3), 1/8-inch (Headset microphone) |
| Output Connections | 1/4-inch TRS balanced (Main Mix outputs) 1/4-inch TRS stereo (Stereo output) 1/8 + 1/8-inch TRS stereo (Phones/Monitor output) |
| Input Impedance | 240k Ohms (Inst-HiZ), 20k Ohms (Line) (Ch1-Ch2, Ch3-Ch4 1/4-inch inputs) >4k Ohms (Ch1-Ch2 XLR input) |
| Output Impedance | 440 Ohms (balanced 1/4"), 220 Ohms (unbalanced 1/4-inch) (Main Mix) 100 Ohms (Monitor output) 2k Ohms (Stereo output) |
| Frequency Response | 20 Hz – 20 kHz (+0, -1 dB) |
| THD | <0.02% @ 1 kHz |
| CMRR | >52dB typical |
| Phase Response | All connections are phase coherent |
| Signal to Noise Ratio | >90dB typical (Ref 0dBu) |
| Equivalent Input Noise | -120dBu typical (XLR balanced, max gain), -95dBu typical (1/4-inch) |
| Maximum Input Level | +8dBu (XLR input), +16dBu (1/4-inch input) |
| Maximum Output Level | +15dBu (Main Mix outputs), +15dBu (Monitor output), +12dB(Stereo output) |
| Maximum Gain (In to Main Out) | +60dB (XLR), +47dB (1/4-inch) (Ch1 input) +55dB (XLR), +37dB 1/4-inch (INSTR.-HIZ) (Ch2 input) +5dB (1/4-inch) (Ch3-Ch4) inputs |
| Maximum Gain (In to USB) | +46dB CH1 (XLR) balanced, +40dB CH2 (XLR) balanced +32dB CH1 (1/4-inch input balanced), +17dB CH2 (1/4-inch input balanced) +33dB CH1 (1/4-inch unbalanced), +23dB CH2dB (1/4-inch unbalanced) +46dB (1/8-inch) (MIC to CH1) -8dB (1/4-inch) (CH3-CH4) -8dB (1/8-inch) (AUX INPUT) |
| Maximum Gain (USB to Out) | +18dB (Main Mix outputs), +18dB (Monitor output) |
| Phantom Power | Switch selectable, +48V DC, filtered, current limited |
| A/D-D/A | 16 Bit, 44.1 kHz or 48 kHz, USB selectable from computer 0.4 ms A/D latency @ 44.1 kHz |
| Computer Interface | USB Class compliant plug-and-play Mac and PC interface |
| Chassis Type | All steel black finish |
| Power Requirements | Via USB port (5V/500mA) of the computer or via USB power adaptor provided and connected to AC100-240V 50/60Hz |
| Dimensions (HWD) | 1.75-inch x 5.1-inch x 7.5-inch (45mm x 130mm x 191mm) |
| Weight | 1.56 lbs. (0.71 kg) |
Note: 0 dBu = 0.775Vrms
ART maintains a policy of constant product improvement. Therefore, specifications are subject to change without notice. Go to www.artproaudio.com for the latest information and support.
