Most multimeters measure only 50Hz and 60Hz accurately. Sometimes only your sub-woofer plays those frequencies. Other channels on your 5.1 amplifier produce those frequencies at very low levels (10mV).
ew, thought so....time for scoping. I do have subwoofer, bought it just because my speakers didn't output enought bass for my liking, even they are car speakers in custom made boxes, 6x9'' 4 way, sony xplod, only they were bought used and it sounds like coil or something is hitting something (not bottoming thought) at left front channel. Haven't seen anything that would cause that noise during bass-based music, but i'm planning to buy new pair, probadly similar because sound is good so makes buying easier with these specs (unless these specs are false of course....)
Bit off-topic there perhaps
My "VU bar graph" does not connect to my amplifier because its input is a microphone. It displays the loudness of the TV, the stereo and talking.
ah, clever. That was in my mind too but have absolutely no clue what sort of microphones do their job for such application, and the there's placing ''problem'' too
is that veroboard in that enclosure double sided? nice build & schematic!
i do understand that peak-detector section somewhat, but, what function is with those q1 & q3? and i suppose for mic-amp section, non-inverting output has dc-offset made with those 100k & 47k resistors. C1 is at lest so dc won't go from power rails to that non-inverting output yes?
Just trying understand topology in that circuit, i see less point using circuit unless knowing what's happening there...