With the Asus Z97-AR that has Realtek ALC 892 + Crystal Sound 2, can I use recent Realtek Audio drivers, or do they have to be from the ASUS website to support Crystal Sound 2?
Asus' Crystal Sound 2 and ASRock's Purity Sound 2 are just marketing gimmicks. You can use the reference Realtek drivers on any motherboard that has onboard Realtek audio.
just download your drivers from the Asus website.
I wasn't sure if they had to be specific drivers to use the features of the amp, but the problem is when I put Amplifier to Front Panel rather than Auto Switch (I'm using the rear audio ports), my sound is extremely low pitched and sounds muffled. With the newest Realtek HD Audio Drivers (R 2.78), it sounds like how I described when my amp isn't being used, even though I set it correctly. The Asus site only lists 2 drivers for Realtek HD Audio under my motherboard, both over a year old. I think there may be a few other Asus motherboards that have Realtek ALC892 + Crystal Sound 2, should I look if those motherboards have more recent drivers?