airplayairport
I have an airport express connected to basic (but not crappy) speakers. When I run audio directly to them it plays fine, but when I run audio from either my iPhone or Mac to the speakers via AirPlay, I get crackly distorted sound if the volume slider is above about 75%.
Does anyone know why this could be? I have the airport set to extend my current network; could that affect it?
It depends on the rev of Airport Express. The older Airport Express' only extended the 2.4GHz band.
The last Airport Express (before the change that makes it look like a white AppleTV) could extend either band.
The latest rev (looks like white AppleTV) will also extend either band. From what I understand, if your 2.4 & 5GHz band have the same network name, it will extend the band that has the strongest signal (since there isn't a way to select it in the Airport Setup).
If you have separately named 2.4 and 5GHz network names, then it will extend the network you specify.
Funny story.
Switching B from "Join a wireless network" to "Extend a wireless network" seemed to fix the problem instantly, despite the caveat in that Apple KB doc.
Two days later, the problem has returned. It seems that I can deliberately exacerbate the problem by using extra bandwidth, such as by running a speed test (over WiFi, of course).
Best Answer
Network issues only ever result in the audio cutting out, they can't really change the content.
Distortion means your speakers get overloaded. Turning down the volume is your only option.
The reason your speakers are fine on the Mac is that after the slider in iTunes the sound gets further attenuated by the system volume buttons on your keyboard. If you turn those up far enough you'll get distortion as well.