So, a few weeks back, I posted a thread about my loud HDD, it was a Seagate, and since I've heard so many terrible things about that certain model, I decided to go down to the Apple Store and have my computer checked out. So, after about a week, they finished working on it, and they even put a new HDD in! Now, it's a Hitachi HDD 1TB. So, I went online, and to me it looks like people have been having these grumbling noise issues with their iMacs on all sorts of HDD, Seagates, WD, Hitachi, etc. So basically, it's not the HDDs themselves, it's the iMacs. And I'm sure that this whole noise 'problem' could be fixed with a simple firmware update, or if Apple put some sort of padding around the iMac itself, because Al doesn't eliminate much noise. Anyway, post in this thread if your iMac is making grumbling noise.