In future, please put crash reports in spoiler tags, placing [spoiler] before the crash report and [/spoiler ] after it. I've fixed this particular crash report for you.
You've got a problem with LWJGL/OpenAL, the software that controls how audio works in Minecraft. Here's what I'd try doing in order of what I'd try:
- Run FTB as an administrator (right-click on the launcher, click Run as administrator)
- Turn your sound off while in-game
- Open up the FTB launcher and find your install directory (Options --> Install Directory); go there in Windows Explorer, right-click the folder and click Properties, then un-check the Read-only box
- Follow the instructions below to update LWJGL/OpenAL
Head to http://www.lwjgl.org/download.php and download the newest version of LWJGL (lwjgl-2.9.0.zip once you click on the link to Sourceforge.) Once you've done that, you'll need to determine where FTB is installed on your computer. This can be done by going to the FTB launcher's Options tab, where it should list your install directory. Open up the ZIP archive that you downloaded, preferably using 7zip or similar, and also go to your FTB install directory.
Below, ZIPARCHIVE refers to the ZIP archive of LWJGL you downloaded from the LWJGL site. INSTALLDIR refers to wherever FTB is installed to on your computer.
Open up ZIPARCHIVE/lwjgl-2.9.0/jar and copy-paste lwjgl.jar, jinput.jar and lwjgl_util.jar into INSTALLDIR/ultimate/minecraft/bin. Then, open up ZIPARCHIVE/lwjgl-2.9.0/native/windows and copy-paste everything there into INSTALLDIR/ultimate/minecraft/bin/natives.