The cheapest option would be to get a simple 'USB audio adaptor' like this one: (usb-stick)-pc-mac The fundamental problem is that the computer can't both record and play back sounds through the one audio socket, so at best you would be continually swapping the plugs between your Casio keyboard to record, and your headphones or speakers when checking the recording you made with Audacity. This is not really intended for what you want to do. Like many laptops, according to this page your ASUS UX51 has a 'combo audio socket'. The 'headset' option should let you record sound, but.

I would have expected you had three options, not the two that you mentioned: 'headset', 'headphones', and 'speaker out'. When you are done, just export the audio as an MP3 file and return your Mac’s sound settings to the original state (set Output as Internal Speakers or Line Out).Windows asks if what I am plugging in is a headphone or 'speaker out'. Play the audio inside any app, switch to Audacity and hit the record button. You are now all set to record system audio on your Mac. You will then be able to listen to the audio while it’s getting recorded inside Audacity. Next switch to the Recording tab and select Software playthrough. Open Audacity Preferences, switch to the devices tab and select Soundflower (2ch) as the Recording device. Click the flower and set Built-in Output for Soundflower 2ch. Open the Soundflowerbed app (you can find it through Spotlight) and it will add a Flower item to your menu bar. Step 2: Configure SoundflowerĬlick the Apple menu to Open System Preferences on your Mac, select Sounds, switch to the Output tab and set Soundflower (2ch) as the device for sound output. Both are free software, Audacity allows you to record and edit audio while Soundflower helps you route sounds to any other Mac app instead of the default speakers. Install Audacity and Soundflower on your Mac. The technique doesn’t require the line-in port and thus works on newer Apple iMac and Macbooks.

You can record music from any Internet radio station playing in your browser, system audio or even sounds coming from an application open on your Mac. This step-by-step tutorial explains how you can capture any sounds coming out of the speakers or your Mac.

Audacity record computer audio