When setting up the sound in any hall or room, you eventually come to the complicated dance of on-stage mixing: someone is at the board (usually in the back of the hall) while someone else listens to the sound on stage and telegraphs a series of gestures to try and communicate the necessary adjustments to the monitors. Once the monitors are set (if there are monitors), the engineer will then often try and walk around the room and hear if the sound changes drastically from their station to where the listeners are. Mixing sound from the back of the hall is a conundrum: great sound setups require the engineers to be at the most sonically-ideal location in the room, which means that the listeners (and performers) will have a very different experience from their locations. Furthermore, if you don’t have a dedicated sound crew or are trying to set the board up yourself before the concert, you may end up as I have many times in my career: leaving warm-ups or some pre-concert routine to run to the back of the room and make a quick board adjustment. Mobile-friendly mixers offer to simplify the process by letting users control the board using an iPad (or in some cases a laptop) from around the room.
The premise is simple: an app shows a virtual interface which looks like the full mixer, and any adjustments made in the app are executed on the board itself. This allows the engineer to walk around the room or on stage and make adjustments from anywhere. The biggest commercial applications are in large concerts with multiple monitor setups, where an engineer can stand on stage and listen and configure individual monitors (often with the musician standing alongside). This is also a huge benefit for ensembles or organizations that don’t have a full sound staff, though, as one person can easily configure and adjust the sound setup in an unfamiliar room without having to rely on assistance from other people. Furthermore, when the conductor or accompanist (or a singer) is also the sound person, adjustments can be made in real-time without having to leave the stage. Finally, this can also eliminate the need for a snake or laying messy extension cables through the audience, since the board can be placed anywhere, including on-stage if necessary. Mixers like the Yamaha LS9 function without the iPad, making it an accessory through use of a separate app. The LS9 looks and feels like a normal board, and can be operated without the iPad. The Mackie DL-series, though, replaces much of the traditional mixing console with the iPad interface, meaning all control is through the tablet. This saves some space and results in a smaller overall board, although controlling a high number of channels (beyond 8) becomes a bit slower since you have to either sub-group channels together or swipe between different screens of channels.
It’s important to note that many of these styles of mixers are not ready for mobile mixing “out of the box.” Rather than using Bluetooth, which could be built-in but has a much smaller usable range, these styles of boards use wi-fi. Actually, it would be more appropriate to say that they support being connected via wi-fi– you have to buy (and power) an external wi-fi router to connect the mixer to the iPad. This router doesn’t have to be connected to a live Internet connection, though, so you don’t have to worry about whether your performance gym will have an Ethernet cable. Connect the router to the board, and connect your iPad to that router’s network, and the devices will be linked up through the appropriate app.
While the Mackie DL and the Yamaha LS9 are probably the two most widespread examples of this style of mixer, there are others: Behringer has one with built-in wi-fi (no need for an external router) for example, and several other consumer-level manufacturers make mixers for the iPad with a much lower number of inputs. For a robust, professional-grade level of live sound, though, the Mackie and Yamaha boards function like a traditional mixer. If you (or your sound person) find yourself on stage, looking wistfully at the board in the back of the room and wondering if you really have to make one more trip back there, a tablet-compatible mixer may help you manage the mix.