Since KDE 4.7, always on my favorite Arch Linux, I’m facing an annoying issue at start-up. The KDE environment freezes until a sound is emitted and I have to wait for almost 20 seconds before I can use my desktop.

It seems that KMix sound system is too slow to start and the session manager has to wait for it before playing the start up sound. The simpler workaround is to disable this sound, you just have to follow these steps:

1. Open “System Settings” application,
2. Go to “Application and System notifications“,
3. In “Applications” tab, choose “KDE Workspace” in the list view,
4. Click on “Login” and un-check “Play a sound” checkbox,
5. Click on “Apply” button.

It should solve the problem. I made this article from the following one:  http://krisko210.blogspot.fr/2012/02/kde-freezes-for-few-seconds-after-login.html but I did not reuse the driver modifications because it did not seemed necessary.

Hope it helps 😉