The DBR-15 are active stage loudspeakers. 450W RMS, 1000W peak. VOR amplifiers with ideally XLR signal output are suitable for control. On stage, this is often a mixing console. - Due to the active amplifiers, these powerful speakers have 4 fans for cooling. In very quiet environments, depending on the location of the speakers and the power required, these can also become audible in quiet passages or pauses. Especially if the speakers are set up in rather dusty places, as dust and cigarette smoke will cover the fan blades after a while. It may be helpful to consult a specialist for professional audio.