Hi there,
The SWA-W510 Wireless Subwoofer is not compatible with the HW-Q750C Soundbar.
The HW-Q750C Soundbar is only compatible with the included wireless subwoofer. If you would like to increase the bass levels of the subwoofer, press the TONE CONTROL button on your Soundbar to adjust both the Treble and Bass levels. Also you can adjust the 7-Band EQ by pressing and hold the Soundbar Control button for roughly 5 seconds.
~Samsung Solutions