Stereo

A stereo is an object found in all four Sims games. Stereos range from inexpensive "boom box" units to expensive "audiophile" systems. A stereo provides fun for Sims, and Sims can dance with each other to meet their social needs. In all games, Sims will wake up if there is a stereo playing music in the same room, unless they have the heavy sleeper trait.

The Sims
Stereos in The Sims can only play four radio stations. Sims can change the station at any time and can dance to them, but otherwise they remained fairly basic. Sims must walk up to the stereo in order to turn it on or off, or to change stations. House Party introduced a jukebox and a DJ booth that can play five more radio stations; however, these stations were never made available to other stereos.

Speakers
In House Party and Superstar, speakers are 1x1 "stacks" which are placed on a floor or on level terrain. By default, they are turned off, and the player can click on each "stack" to turn it on or off. These speakers can be used to extend the range of an existing stereo in the same room, although Sims cannot dance to these speakers.

In Hot Date, two wall-mounted speakers were introduced that can only be placed on community lots. These speakers play a station unique to that type of speaker which can only be heard if the currently-selected Sim is in the same room as the speaker. Similar speakers playing different stations were also introduced in Unleashed and in Superstar.

The Sims 2
In The Sims 2, Sims can work out in front of stereos, which improves the body skill. Sims can "Listen to Music" while relaxing in bed, if a stereo is in the same room. Unlike The Sims, Sims will use a remote to control the stereo, but must still be in the same room as the stereo to control it.

A bug introduced in Bon Voyage causes Sims to start dancing on the spot when they are instructed to dance near a stereo, even if they are not in the same room as the stereo. A mod by Cyjon fixes this behavior.

Speakers
In The Sims 2, speakers are wall-mounted, and are always considered to be on. The Neukum System Wall Speaker functions like residential lot speakers from The Sims: House Party and will extend the range of stereos. They are available on both residential and community lots.

Most wall speakers are exclusive to community lots and play only one radio station. Players cannot change the station it plays and Sims cannot be told to dance near it. The station the speaker plays can be identified by the speaker's color and by its name.

In Bon Voyage, vacation locals can do the hula or slap dance near a community lot speaker autonomously.

The Sims 3
In The Sims 3, some stereos improve the athletic skill, but the Showtime stereos don't. Unlike previous games, Sims no longer need to walk near the stereo to turn it on or off, or to change stations; all such interactions occur instantaneously. In addition, players can now control the volume of stereos. A stereo provides the "Enjoying Music" moodlet; on normal stereos, this is +20 with a +10 bonus on certain Sims if it is playing their favorite music genre.

In The Sims 3, a Sim with high Handiness skill can perform the upgrade Wire House With Speakers, which causes the "Enjoying Music" moodlet to follow Sims around the house and likewise prevent them from sleeping (unless they have the Heavy Sleeper trait). Unlike the Buy mode speakers in earlier games, this upgrade affects the entire house; the player cannot choose which rooms will have speakers.