I found this old Kenwood sub in my basement that i want to sell. The only problem is, I have no idea if it works. However, i also have a monoblock Kenwood amp set up in my car. If i touch the connectors just to see if the sub works, will that blow anything?
The type of amplifier used for testing should not matter,
but something else might.
Before attempting to test it, you need to know
which of the two main types of subwoofer you have.
If the sub has a built-in amplifier, very little power needs to be applied
to its input to test it, and if it has line-level inputs, it can be tested
by being connected to a preamp output (one that is affected
by a volume or level control) on a receiver or other component,
without any need for a speaker amplifier.
If it is passive, then an external amplifier is needed.
If you are not sure and/or can't figure it out,
have a local audio repair shop check it for you.
Some will test things at no charge; others charge a nominal fee.