Before Apple introduces an easy airplay management directly into osX with Mavericks, Rogue Amoeba Airfoil was the most convenient solution to stream your music on your airplay compatible speakers. However, Airfoil still proposes several interesting improvements compared to the Apple build-in solution. In particular, it allows to stream a specific audio source from your mac ( whereas Apple solution stream either the entire system sounds or iTunes music) and manage multiple Airplay output in the same time.
Airfoil is clearly a very convenient solution but it has a major drawback compare to the native Airplay support : it introduces a notable audio delay during streaming ( ~2 seconds ). This does not sounds as a big deal but it is clearly a bit frustrating days after days, and it prevent to use it in cases where latency is a bottleneck e.g. using Airplay speakers as Garageband output for instance.
Airfoil users, I’ve a good news : there is a workaround to get rid with this delay !
Just before the explanation I would precise the common tagline of every hack method :
Please note that I do not take any responsibility if something goes wrong with my method, you do it at your own risk for your software and hardware parts !
Okay, now it’s done here is the trick :
1- Launch Airfoil by double clicking the icon and maintaining the left option/alt key. This will launch Airfoil debugging mode.
2- Check the “Realtime local playback ” option and set the speaker delay in seconds to “0.0”
3 – click Done and that’s it !
Airfoil now streams your audio outputs with a very low latency !
It is not clear what is the impact of this hack on the stability/performances of the Mac but I didn’t notice any differences.
[Edit june 2016]
Airfoil v5.x has a native setting for latency !
You can set the latency for each speaker in :
Speaker => Advanced Speaker Option