ART ProMIX 3-Channel Portable Mono Microphone Mixer Battery or AC Powered

ART ProMIX: Three Microphones Into One Input

The ART ProMIX is a three-channel portable mono microphone mixer with balanced XLR inputs, individual level controls and a balanced mic-level XLR output. It exists to solve a very specific and very common problem: a camera, a field recorder or a larger console has one microphone input left and three microphones that all need to be heard. Rather than choosing between them or carrying a full mixing desk, this unit sums all three into a single balanced feed that the destination treats as one microphone. Small enough to sit on a lectern shelf or in a shoulder bag, it turns a hard limitation into a non-issue.

Independent Control on Every Channel

Each of the three channels has its own level control, its own switchable phantom power and its own switchable high-pass filter. Independent phantom switching matters because mixing microphone types is normal in the real world: a condenser lectern microphone needs powering while a dynamic handheld beside it does not, and sending phantom where it is not wanted is at best pointless. The high-pass filter, set at -3 dB at 100 Hz, rolls away the low-frequency energy that handling noise, air conditioning and stage rumble push into a microphone before it reaches the summing stage. A moderator running two panel microphones and one audience microphone can therefore set each one correctly instead of compromising across all three.

Understanding the Mic-Level Output

The main output is a balanced XLR carrying microphone-level signal rather than line level. That distinction decides where the cable goes at the other end: a mic-level output belongs in a microphone input on a camera, recorder or console, where it will receive the gain it expects, and plugging it into a line input would leave the signal sounding weak and noisy. Keeping the output at mic level is deliberate, because it means the destination's own preamplifier stays in charge of final gain and the whole rig behaves exactly as it did with a single microphone plugged in. A 1/4 in output sits alongside for headphone monitoring or a second feed, so an operator can hear what is being sent.

Phantom Power at 12 Volts

Phantom power here is supplied at 12 V DC per channel, rising to 18 V when the unit runs on batteries. Most condenser microphones are specified for 48 V but a great many will operate on lower voltages, typically with reduced headroom before the capsule's internal electronics distort, which is why the figure is worth knowing before a session rather than after. For electret lavalier and small-diaphragm microphones commonly used in interviews and conferences, 12 V is usually ample. Checking a microphone's minimum phantom voltage takes a moment and prevents the one surprise this mixer can spring on a user.

Powering It in the Field

Operation is possible either from the included 12 V adapter or from two 9 V alkaline batteries. Battery operation is what makes the unit genuinely portable, because a documentary crew shooting in a warehouse, a field reporter on a street corner or a wedding videographer at an outdoor ceremony simply has no mains outlet to work from. Running on batteries also removes any possibility of mains-borne hum entering the signal path, which is occasionally a reason to choose batteries even where power is available. A clip LED warns when any channel is being driven too hard, which is the one indicator an operator really needs when there is no time to watch meters.

Where the ProMIX Gets Used

Broadcast crews, houses of worship, conference facilities and independent video producers all keep a small microphone submixer within reach. A church with a lectern microphone, an altar microphone and a handheld can feed them all into one input on an existing system without buying a bigger console. A documentary team can put three lavaliers on a panel and hand the camera operator a single cable. With 60 dB of available gain, 0.0002 percent distortion and 600 ohm balanced input and output impedance, the summing stage stays clean enough that nobody downstream can tell three microphones went in where one came out.