Maker Pro
Maker Pro

Anyone else use a medical stethoscope ?


N Cook

Jan 1, 1970
I've previously only used one with the diaphragm replaced with a length of
polythene tube to discover where squeels or squeaks were coming from in
mechanical equipment.
This time a bass speaker that was making rattling/scratchy noises when
driven with sub-100Hz feed.
Nothing wrong with cone/gluing/skirt/spider etc and fingering the driven
cone (wearing ear defenders) made no real difference to the random rattle.
Could only summon it to order by placing the cab on its side, otherwise in
band use it would appear intermittently.
Decided to listen with the stethoscope , with diaphragm attached , while
driving with 60Hz, not deafening as presumably because not tuned for
Rattley/scratchy noise was then noticeably prominent in one area of the
speaker frame mounting.
Removing again from the cab , there was a length of unglued and uncompressed
foam, about 4mm at widest, around the mounting flange that must have been
resonating and flapping against the frame.