Solved! Why when I connect my subwoofer Yamaha YST SW215 with my speakers to my external soundcard, all I get is a low bass sound with no speaker sound

Oct 8, 2020
Hi guys and girls. My name is Jim and I have an audio system, amplifier NEC, two speakers and a subwoofer Yamaha YST SW215. First I connected my sub to my amp, the speakers to the sub and the amplifier to my external sound card on my pc. Due to the fact that the amp has a problem with the volume knob and you have to adjust it just the right way to have sound from both speakers and for fear of short-circuituing the whole system, I decided to exclude the amp from the audio system. So now, I have my subwoofer which has a built in amp and has its own power supply connected to my speakers and then to the sound card. But when I tried to play some music all I could hear was the bass of the subwoofer and no sound from the speakers. Why is this happening and how can I fix it???
It is happening because the mono amp built into the subwoofer is just for the subwoofer.
When you connected the sub to your amp you were using that amp to drive the satellites not the sub amp.
You would need powered speakers or another amp to get it working without the NEC