I recently bought a pair of XR-824s for my home studio, for mixing mainly, and lightweight finalization (mastering) of my own tracks and collaborations with other artists. I couldn't be more satisfied, Mackie have delivered once again.
Bass response is extended and controlled. Vocals, guitars, and synths sound crystal clear and well-placed in the stereo field. These speakers are almost transparent in the mid-range to my ears, which renders mixing easy and swift. Transients in the upper mid and high-frequency band are served quickly without causing any fatigue for a considerable extent, at least compared to my Adam A7Xs.
I prefer mixing with the XR-824s instead of the Adams, for me the former employ better a balance between clarity and warmth. The A7Xs might sound more flat to some people, but that doesn't mean that the Mackies are not suited for subtle or surgical moves that require accuracy.
Build quality is excellent overall, and difficult to beat at this price range. I wish they had placed an easy to reach on-off switch or button at the front, although I can understand why they opted for a minimal front face look instead. The speakers look, feel and sound amazing. Let these babies burn-in and after a few days of getting used to them, you'll forget they are even there, especially if you plan to upgrade from a budget model.
Once again, kudos to Mackie R&D.
Pros: Premium looks, amazing sound, more than fair price.
Cons: Lack of front facing on-off switch, which can be remedied by the auto turn on-off feature in some situations.
Disclaimer:
Different speakers sound different to different ears and rooms. The XR-824's response and clarity might be the best fit for my ears and work-space, and may not sound exactly the same to you. To be sure, give them a try before buying them if possible, at your local demo room.