This is the problem:

I have dug out a set of Ozaki 4.1 speakers (carefully all kept
together in a plastic bag).. but not with their power adapter.

I have a collection of power adapters, and they are never marked up
with the device they came from.... I also have a multi-settings power
adapter that I can use to test these speakers.

There is nothing on the speakers to indicate what the power adapter
should provide. Though I have another set of older twin speakers
(Creative) and they require 9v.

I was wondering what settings I could try to see if I can get the
Ozaki set tested.

The Ozaki pdf manual that I have managed to locate does not go into
these details.

Thanks