How to Play Music on One Computer Through Another Computer's Speakers
Playing audio on your laptop through another computer solves several problems. The obvious issue is volume, since laptop speakers are rarely very big. But it's also common for laptop sound to fail. Sound drivers develop errors. Speakers overheat or blow out. Sometimes you can't even tell whether it's a software or hardware issue. Connecting to another computer bypasses the problem completely, and the only equipment you'll need is available at most electronics stores.
2). Locate the line out-jack on your laptop. You can also use the headphone jack. If your computer does not have either of these, or if they are broken, you will need a USB audio interface in addition to the audio cable.
3). Attach the 3.5" to 3.5" audio cable to your computer's line-out or headphone jack. If you're using a USB interface, attach the interface to a USB port on your computer and attach the audio cable to the line-out jack on the interface.
4). Locate the line-in or microphone jack on the computer with functional sound. Plug the other end of the audio cable into this jack. If the functional computer doesn't have either jack, you'll need another USB audio interface.
5). Turn the volume on the sending laptop all the way up. Open your media player and turn it to its maximum volume as well.
6). Open the receiving computer. Right-click the volume icon in the system tray and click "Recording Devices”. The attached audio cable or interface should show up on the menu as a microphone. Right-click its icon and click "properties" on the drop down menu.
7). Click the "Listen" tab and check the box labeled "Listen to this device". Click the drop-down menu labeled "Playback through this device" and select the computer's default speakers. Click the '"Levels" tab and raise the microphone level up to 100.
8). Play your audio on the sending computer. You should hear your audio through the speakers of the second computer.