Editing Macintosh IIsi (section)

== Audio ==

The Macintosh IIsi was the first Macintosh with built-in audio input.<ref>{{cite web |url=https://lowendmac.com/1990/mac-iisi/ |title=Mac IIsi |publisher=Low End Mac |access-date=2026-02-09}}</ref>

* '''Audio Output''': 8-bit stereo, 22 kHz
* '''Audio Input''': 8-bit mono, omnidirectional microphone input
* '''Output Jack''': 3.5 mm stereo headphone jack
* '''Input Jack''': 3.5 mm microphone input
* '''Internal Speaker''': Mono speaker on daughterboard

The IIsi develops sound issues over time due to its modular construction. The internal speaker mounts on a daughterboard with spring contacts that connect to the logic board. Speaker vibrations cause fretting of the contact surfaces, resulting in intermittent audio dropouts. Cleaning the contacts with a pencil eraser fixes this.<ref>{{cite web |url=https://en.wikipedia.org/wiki/Macintosh_IIsi |title=Macintosh IIsi |publisher=Wikipedia |access-date=2026-02-09}}</ref>