The desire to be able to organize large scale, public events as safely as possible despite adverse circumstances has been driving numerous creative minds since the beginning of the covid-19 pandemic. One such person is Tobi Hoff, who, among other things is known as Deep Purple’s FOH audio engineer and Rea Garvey’s monitor engineer.
Since the summer of 2020, Tobi and his company LAC Labs have been developing a 19“ rack mounted disinfection device (3 U, depth 39 cm), a welcome disinfection and hygiene aid for events of all kinds. Li.LAC is a rack mounted drawer which disinfects microphones, headsets and other small items through ultraviolet light (UV-C). The effectiveness of the method and the product has been approved by independent institutes including the University Medical Center Groningen (UMCG). Since the spring of 2021 the first Li.LAC units have been on sale.
Safe. Simple. Fast.
As an experienced live sound engineer, Tobi knows about the stresses and strains equipment can be exposed to on the road. Li.LAC has a correspondingly robust design: “Safe. Simple. Fast.” is the claim that LAC Labs assigns to the disinfection device in its advertising.
The operation of Li.LAC is self-explanatory: The disinfection is activated by pressing the rotary encoder wheel on the front panel. The cycle takes five or ten minutes. At the end of the disinfection process, the easy-to-read countdown display lights up in green – the visual feedback is useful to provide reliable information about a successful disinfection.
Irradiation without tanning streaks …
The intensity of the UV-C light is deliberately distributed heterogeneously within the irradiation chamber: The head of hand-held microphones and hand-held transmitters are irradiated with significantly more energy (800 – 4,000 μW/cm²) than the shaft (350 to 600 μW/cm²).
Up to three microphones can be placed onto the metal grille inside Li.LAC. The purpose of the grille construction, which is reminiscent of a wine bottle rack, is to create as little shadow as possible, as the latter could impair the effectiveness of the disinfection. Headsets, clip-on microphones and other small items can be secured with an optional spiral spring and a cable tray.
The two UV-C tubes (wavelength 254 nanometers) inside Li.LAC are sufficiently robust for everyday touring and events: They sit firmly in their sockets and are additionally secured with two metal clips. LAC Labs recommends replacing the lamps after 4000 disinfection cycles.
Of course, special attention was paid to the operational safety of Li.LAC: The UV-C radiation, which is harmful to humans, is automatically switched off as soon as the drawer is opened. The chamber is light-tight so that radiation cannot be emitted to the outside. LAC Labs GmbH grants a 24-month guarantee on the devices.
No effect without side effects
“Where there is a lot of light, there is always shadow,” is a phrase that seems appropriate in connection with Li.LAC. The remarkable disinfection effect cannot be achieved without a certain impairment of the material, and it is obvious that the high UV-C intensity causes plastics and foams to age faster than it would be the case with normal stage lighting. Last year, LAC Labs conducted extensive UV-C long-term exposure tests and documented the effects of thousands of disinfection cycles on various microphones from well-known manufacturers. Detailed results can be found here. Such “side effects” are not objectionable, as disinfectant sprays or alcohol wipes are also known to attack the material and the smell they cause is not necessarily everyone’s cup of tea.
Unrivaled professional product
The Li.LAC microphone disinfector can be ordered from selected resellers. Among the enthusiastic users are well-known audio professionals such as Tim Ehrenfried (currently on tour in Germany with Li.LAC as Jan Delay’s monitor engineer), who says that this innovative product is exactly what they were looking for to establish hygiene and disinfection standards for their production.
Tobi Hoff looks optimistically into the future with regard to Li.LAC: “There is currently no competing product!” states the graduate engineer and reports consistently positive feedback from satisfied users. “It’s great that Li.LAC is so well received – but of course I’m also looking forward to the time when I can be behind the mixing console again at live concerts in sold out arenas but also with a Li.LAC disinfection unit by my side.”