Kiwifruta:
Just realised that so I know where the fault is, I'll need a multimeter too.
Jaycar have a good range. You want silicon wires (ie very flexi) on the probes
Or Trademe . MM's are dirt cheap & worth nothing to sell , so bargains galore .
Ive a bit of a collection from when I was an electronic hobbiest, they arnt worth selling :-)
Could possibly send you one for free , if in NI .
To test a bass speaker, just connect a 1.5v AA batt across it . Easiest way without a meter .
Replacing a speaker, in theory they need to be matched to the xover design & box design.
In practise it doesnt matter too much if not too fussy.