rtrinidad

My stock premium sound system on my GS 350 F Sport seems to be losing bass. The woofer(s) seem to be working but the thump seems to be lessening. It appears that the volume to the woofer drops and raises while a song plays. Anyone have this issue? If so, any idea what it might be? Sometimes it sounds (feels) fine. Other times it's like reduced the bass on the controls. It does not abruptly cut on and off. It's a gradual change.