Hi R...
if the sound signal is running thru the sub and then from the sub into your speakers...then the sub is [partly] operating otherwise the signal would not carry thru the sub to your speakers.
However, i think you may need to check that the sub itself is playing bass. To keep life simple...
...focus on making sure the RCA-outs from your integrated (OR the speaker outs from your integrated) are correctly connected to the sub.
....Crank the sub and see if ANY bass comes out of it. Play with sub volume (turn it up)...and play with crossover...does any bass or music come thru at all?
if the sound signal is running thru the sub and then from the sub into your speakers...then the sub is [partly] operating otherwise the signal would not carry thru the sub to your speakers.
However, i think you may need to check that the sub itself is playing bass. To keep life simple...
...focus on making sure the RCA-outs from your integrated (OR the speaker outs from your integrated) are correctly connected to the sub.
....Crank the sub and see if ANY bass comes out of it. Play with sub volume (turn it up)...and play with crossover...does any bass or music come thru at all?