NHT Evolution System - Manual (Page 45)

10.0 Maintaining your system
Your NHT Evolution speakers and electronics
require minimal maintenance under normal use.
The cabinet may be cleaned using a soft cloth.
There is usually no need to use fluids such as
cleaners or wax to clean the surface of the
speakers. The durable lacquer finish is designed
for minimal maintenance. To clean the grille, first
remove it from the speaker, then brush lightly
with a soft brush or use a vacuum on its lowest
setting. Do not attempt to clean the actual dri-
vers. To remove dust, you may use a feather
duster. Do not expose the speakers to direct
sunlight, high temperatures, or moisture.
Electronic components should be wiped with a
dry, soft cloth to remove dust. Do not use any
liquid near or on the electronics as it may cause
electrical shock.