Spare change on a speaker cabinet

My guess is that if it has any effect at all it comes from a metal object vibrating in sympathy with certain musical notes, addin g a sense of high frequency sparkle. There is a company that makes little bells (they call them "resonators") out of precious metals attached to exotic wood blocks. You are supposed to put these in various places around your room to improve imaging. They may very well produce a pleasant effect (never heard a controlled demo, although the manufacturer was going to do one before he got distracted). Maybe a similar effect.
There is no way a couple coins could shift the resonant frequency of a hundred pound cabinet enough to change its damping / ringing properties.

Be sure to use Euros, if the speakers were made in the E.U. but Pounds Sterling for British speakers :-)

10cents 25cents 10cents placed at the front of the speaker.
Apparently Canadian coins work better.
E-mail me and I will sell you some.

The .90c tweak thought that was hella funny way back in the day, maybe folks will bring this back, old school baby..

Hahnzie - Have you heard the one about little battery powered clocks that do all sorts of mystical things?

Only $50 for a $5 POS. It makes the change tweak look smart. Just don't let the wife throw it out when you're not looking or else all those epiphanies will be shown to be nonsense.

Couldn't have that could we?