In Super Smash Bros. Melee, the monaural/stereo option has stayed. A new option, however, adds a music and sound effects slider; depending on which way the slider is set, the game will either make the sound effects or music louder, with setting it all the way to one side completely removing one of the options.
The Sound options page in Super Smash Bros. Brawl has the slider mechanism from Melee, but the monaural and stereo option has been removed, as these settings are modified in the Wii's internal options. Additionally, a link to the Sound test has been added.
In Smash for 3DS / Wii U, the Sound options menu returns, but is revamped from its previous incarnation. The slider for sound effects and music has been removed, and instead, Music, Sound Effects, and Voices have three separate sliders, allowing the player to decide how loud they wish each option to be, tested by "Battlefield", the Mario coin sound used in Mario's Super Jump Punch, and Mario's voice clips respectively. A button can also send players to the Sound Test. Once again, the player is unable to decide on the output configuration of sound, as such settings are determined by the Nintendo 3DS' and Wii U's settings - and in the Wii U's case, the GamePad's sound has no settings options.