Signed Version for macOS Big Sur (11.1) and earlier

M1 chip-based Macs are NOT YET SUPPORTED

PLEASE READ BEFORE ATTEMPTING TO INTALL!

Note that the even though this Soundflower extension is signed, but the installer is not! You will have to hold the control key down to open the Soundflower.pkg installer for the first time.

Apple makes you jump through a few hoops. The first time you run the installer (Soundflower.pkg), it will ask for your admin password, and will FAIL! A security alert will appear, with a button to take you to System Preferences "Security & Privacy - General" pane. Once there, there should be an "Allow" button (**) that you will need to click on to give permission to use Soundflower (developer: MATT INGALLS). Then, RUN THE INSTALLER AGAIN. It should inform you installation was successful. If the "Allow" button is disabled, you may need to click the lock icon in the bottom lower left corner first.

(**) If you see an "Open Anyway" button in the Security Preferences, this is something different!!! Most likely because you tried (and failed) opening the installer by double clicking without holding down the control key. If so, click the "Open Anyway" button which will display another window. Then click the "Open" button in that window to launch the installer. Now you can follow the instructions above to get the "Allow" button to appear in the Security Preferences.

NOTE: This is only the Soundflower kernel extension. The SoundflowerBed app is retired. A new replacement is in the works. In the meantime, you can take your chances with an older version of Soundflowerbed, but you can do a lot with a Multi-Output Aggregate Device. Here's an example:

Say i want to play some audio in iTunes, but record it in Quicktime while listening to it out of the built-in speakers. Here is how i would set it up:

*in iTunes:

start playing audio

Open Audio MIDI Setup: (found in /Applications/Utilities)

hit the '+' button in the bottom left corner and select "Create Multi Output Device"
in the the panel that appears on the right, select "Built-in Output" AND "Soundflower (2ch)"
then hit the button with the gear icon bottom left and select "use this device for sound output" (you should still be hearing your iTunes output -- it is now going to both Soundflower and the built-in speakers)

Then In Quicktime:

create a new audio recording
in the popup menu next to record button select "Soundflower (2ch)" as the input
(you should now see record levels changing)
hit record!

Signed Version for Yosemite/Mavericks

Beta version of a signed, 128-channel version of Soundflower.
(as required by Apple, this version of Soundflower.kext will be
installed in the /Library/Extensions folder,
not in /System/Library/Extensions as previous versions were).

FIRST try the downloading the Soundflower-2.0b1.dmg installer.
After downloading, control-click on Soundflower.pkg and select "open"
(then click "Open" in the "unidentified developer" alert window)

IF THE INSTALLER FAILS

look in System Preferences:Sound and see if the old Soundflower devices are still loaded.
if so, open a terminal and type:

sudo kextunload /System/Library/Extensions/Soundflower.kext
sudo rm /System/Library/Extensions/Soundflower.kext

confirm the old Soundflower devices are unloaded,
then try running the .pkg installer again

AND IF YOU ARE STILL HAVING TROUBLE

you can try installing manually:

Download the Soundflower.kext.zip file.
Assuming it is automatically unzipped in side your Downloads folder,
Open a terminal and type:

sudo mv ~/Downloads/Soundflower.kext /Library/Extensions
sudo chown -R root:wheel /Library/Extensions/Soundflower.kext
sudo kextload /Library/Extensions/Soundflower.kext

if that all works then you can remove the old version:

sudo rm /System/Library/Extensions/Soundflower.kext