Hi All! I use Mackie SWA1801 with SA1521 for 3 months, I'm about 20 indoor and collection outdoor concerts and I've never had a problem! I always had one fucking her. We have a big performance in BF, you good filters. There is a limiter Intgr the box, I saw lights in a festival with both groups of metal. Personally I have nothing to say about this hardware, Mackie is really reliable, I even a pair of HR824, the Butcher!