Speaker serial number locations vary depending on the brand and sometimes the model, but check the product itself or the packaging for stickers and labels, as these often bear the serial number. Most serial numbers are numeric, and number length can vary widely.
Locate the rubber strip on the bottom of your speaker to find the serial number on a Beats Pill speaker. If you have a Beats Pill XL, locate and pull back the rubber flap that covers the ports on the back of the speaker. Find the serial number that begins with the word RAVE and consists of both numbers and letters on the inside of the flap.
ION sound systems have a 17-digit serial number that begins with the number 21 in parenthesis. On some ION products, including the TTUSB, TTUSB10, TTUSBDC, LP Dock and LP 2 CD USB, the serial number is underneath the turntable platter. To access the serial, grab the platter using its two surface holes, and pull up. In most of ION's other products, locate the serial number at the rear or bottom of the speaker unit.
Most Bowers and Wilkins speakers have the serial number on the terminal tray where the speaker cables connect. Some other models have the serial number on the plinth or on the underside of the cabinet base.