New to recording with DR-40X

[Barak]

Hi. I had to record sound from a laptop that was connected through Bluetooth to a big standing speaker. I connected my 3.5 red & white cables from my Tascam to the Line-Out red & white RCA on the speaker. But the Tascam didn't recieve the sound from the speaker, it just recorded the overall sound from the Tascam's microphones.
What could be the problem? Maybe needed to click some buttons on the speakers? Maybe I need to turn the Tascam's microphones off?

 

[Arjan P]

What speaker is that? And are you sure they are Line Outs? Could also be that you did not set the recording input Source to Line In on the DR-40X