MBL toned things down for its MBL Corona Line (www.mbl-northamerica.com) of audio equipment. The components are designed to power or complement the German company’s more compact Radialstrahlers—loudspeakers that radiate sound 360 degrees—not its power-hungry flagship Radialstrahler MBL 101 X-treme. The Corona Line includes mono, stereo, and integrated amps; a tuner; a preamplifier; and a CD player. The components are priced from about $8,800 to $12,500. The C15 monoblock amplifier delivers a relatively mild though still sufficient 500 watts at 4 ohms. Its power supply and transformers are magnetically shielded and electronically isolated to ensure the 360-degree audio from a speaker such as the Radialstrahler MBL 120 reaches listeners in its purest possible form.