Denmark’s legendary Green Concerts (Grønne Koncerter) broke all records this year, welcoming over 190,000 people to eight open-air shows across eight Danish cities in eight days. Now in its 26th year, Grøn Koncert is a charity event sponsored by Tuborg’s Green Label beer (hence the name) that traditionally showcases Danish talent with all profits going to Denmark’s foundation for Muscular Dystrophy. As can be seen from the attendance figures, Grøn Koncert is a hugely popular event nationwide and demands the same levels of professional sound reinforcement as the internationally famous Roskilde festival. In fact, DPA Soundco, the main provider for sound reinforcement at Roskilde for several years, also handled Grøn Koncert this year, and supplied their brand new PA fresh from Roskilde’s main ‘Orange’ stage, which is powered by Lab.gruppen’s new flagship Powered Loudspeaker Management system, the PLM 10000Q.
DPA opted for a very similar configuration to the Roskilde system, based on JBL Vertec cabinets handling the mid-high frequencies powered exclusively by a total of 34 Lab.gruppen PLM 10000Q devices, running two Vertec loudspeakers each. All of the PLMs were run on AES for the main signal and on analogue for redundancy. The bass frequencies were handled by 18 Nexo CD 18s per side powered by 9 Lab.gruppen fP Series fP 6400 power amplifiers.
DPA Soundco’s technical guru, Gorm Jakobsen, is already a fan of the new units. “We’ve always had Lab.gruppen amplifiers in the warehouse at DPA, but the new PLMs definitely take amplifier and processor technology to a new level,” he noted. “We tested them extensively on other festivals before putting them on Roskilde and then on Grøn Koncert, and the results were astonishing. We asked everyone who used them to drive them as hard as possible, and we adjusted the settings accordingly, trimming them back each time so that by the time we arrived at Roskilde we had the perfect settings. Our Vertec system has never sounded so good, and yet the PLMs were only running at 50% of their maximum temperature. We didn’t have to touch a thing for Grøn Koncert, and it worked like a dream.”
“Technically speaking, the PLMs are wonderful to work with out in the field,” he continued, citing their performance monitoring and load verification capabilities as being particularly noteworthy. “You know exactly how each unit is performing at any given time,” he said. “I particularly like the limiter settings found in the ISVPL (Inter-Sample Voltage Peak Limiter) which allows you to tailor each power output to the load connected to it, and then control it. What’s more, it automatically detects any voltage peaks in the signal and reduces the gain accordingly – very clever!”
“I also like the fact that the PLM can be any type of amplifier you want it to be, and in fact, several amplifiers at once. You simply configure each channel to handle whatever load is dictated by the loudspeaker and away you go,” stated Jakobsen. “Another big plus is the LoadSmart load verification test. Once your system is set up and tuned, you can run this quick test which will tell you instantly if the reality of your system corresponds with what you’ve told the PLM. For instance, any wiring problems, like unconnected or mis-connected speaker cables will show up instantly because the PLM will register “no load” instead of what you’ve told it to expect. This is a really useful tool that helps both system performance and maintenance.”
Jakobsen added a final word on sound quality: “The PLM’s performance as an amplifier is irreproachable, but there is no doubt that the marriage between Dolby Lake and Lab.gruppen has produced a sound quality that really is a cut above everything else. We mustn’t forget that PLM isn’t just an amplifier, it’s a networkable loudspeaker processor. The Dolby Lake crossover that is part of the processing package is an extremely high quality crossover, and the difference it makes to the system is audible. It sounds noticeably better than other industry standard outboard crossovers that we have used in the past.”
“It’s fair to say that as a result of all the advances in technology offered by PLM, you spend more time in the warehouse for the initial system set-up than you would using a traditional amplifier,” remarked Jakobesen in conclusion, “but the recompense is that you gain a huge amount of time on site, not to mention the savings in rack space, weight and the improvements in sound quality. In my opinion, PLM is a perfect live sound tool, and I’m sure I’ve only just scratched the surface of its true capacity – I’m looking forward to learning what else it has to offer.”