Yamaha DXS18XLF

Record the full-range speaker models and the inputs and filters on every subwoofer and speaker. Follow the preset and diagram for that exact system. Check the THRU/DSP OUT selection and the signal sent by each output; an XLR connector alone does not establish that the required filtering is applied. During the check, confirm a clean signal in both paths and the intended filtering. If one path is missing, check the output selection, cable and destination input before increasing gain. Listen to the subwoofer and full-range speakers separately, then together, starting at a low level. Save the settings and identify who is responsible for alignment. Speakers from another generation require their own documentation.

Mark the listening points, the position and orientation of each subwoofer and the signal feeding it. Compare the same reference on stage and in the audience; weak bass at one point may result from interactions and room effects rather than a lack of power. Have the technician assess positions and a documented arrangement, including cardioid mode where appropriate. Do not turn cabinets or reverse polarity at random. Check the result in every required listening area.