It's a stereo speaker but you can add another one to make a stereo pair.

The resulting vibrations are similar to those produced by a stereo speaker.

The sound waves are generated by a sound source, such as the vibrating diaphragm of a stereo speaker.

Key to its success has been front-facing stereo speakers that give it the best sound of any phone.

The legal high was discovered stuffed in bottles hidden in stereo speakers.