Panasonic SC-HTB10P Service Manual page 23

Step 6 : Ensure Subwoofer Speaker Front (SP3) wire is properly dressed into the Front Panel Assembly rib.
Step 7 : Ensure Subwoofer Speaker Front (SP3) wire is properly dressed into the Front Panel Assembly between rib and boss.
Step 8 : Ensure Subwoofer Speaker Rear (SP4) wire is properly dressed into the Front Panel Assembly ribs.
23