by Versilaryan » 09 May 2012 01:14
Find your sound driver's audio settings and increase the buffer. If that doesn't work, disable your audio driver and re-enable it. (If you're using Windows, right-click that little volume icon, click "Playback Devices", click in the window and make sure "Show Disabled Devices" is checked, then right-click your audio driver to disable/enable it.)
The reason it's probably working for Audacity is that Audacity defaults to your most basic audio drivers, while REAPER will default to your fanciest one. Assuming you have ASIO4ALL or something similar, if your buffer size isn't large enough, you'll get those crackles. Even if you aren't using fancy drivers (in which case, you really should download ASIO4ALL), REAPER probably lets you set things more precisely than Audacity, which might be causing the problems.
The biggest difference between an external and an internal sound card is that the external ones have far less interference from electronic activity happening inside your computer. And if you're using a laptop, chances are that an external sound card will be higher quality than the one that came with your computer. If you got a gaming laptop or something with a good sound card, then there's really no audible difference in sound quality as far as playback goes, unless you're an audiophile with really good speakers/headphones.
The trade-off is that internal sound cards use your computer's PCI connection, which is much faster than a USB or FireWire. I have heard of external sound cards that use PCI, though, so if that's a concern (and you're using a desktop), there's that option.