Engadget
Bluetooth and Wi-Fi make different compromises, and a wired connection alone doesn't guarantee better sound.
Wireless speakers are often treated as the option, while wired systems get cast as the choice for better sound. The connection alone doesn't settle this question, though. Speaker design, amplification, source material and room acoustics all affect what you hear.
Traditional passive speakers need a separate amplifier, which sends the amplified signal through speaker wire. Powered, or active, speakers have amplification built in. A wireless speaker receives audio over Bluetooth, Wi-Fi or another wireless connection, but that doesn't necessarily make it cable-free.
Many home models still plug into an outlet, while portable speakers run on batteries.
One advantage of passive wired systems is modularity. Because the amplifier and speakers are separate, you can replace or upgrade one without rebuilding the whole setup.
A wired connection also removes Bluetooth transmission from the latency chain. Bluetooth can introduce a delay between the source and the sound reaching the speaker, with the amount varying between devices. The Bluetooth Special Interest Group's explanation of LE Audio describes buffering in Bluetooth Classic Audio as one source of that lag and explains how LE Audio can reduce it.
The quality of the speaker, amplifier and recording still matters, as does the room you're listening in.
Wireless speakers are easier to place when you don't want to run audio cables across a room.
Passive models give you more freedom to replace the amplifier or speakers later, and the wired connection avoids Bluetooth latency.