I recorded this right before Christmas and finally sat down to show you how I’m using the Topping DX5II as a “mix/master” monitoring hub—both for headphone EQ and basic in-room speaker tuning with REW. The goal here isn’t to chase a perfect target curve just because the graph looks pretty. For headphones, I keep it simple: I pull up my headphone measurement on Squiglink (in this case the Audio-Technica R70xa) and I only nudge things until the response sits inside the “preferred bounds.” Conservative moves, minimal surgical stuff, and then I check references—tracks I know by heart—before I commit. For speakers, I walk through the practical REW workflow (measurement mic, interface with a mic pre, mic stand, REW software), and I point you to Julian Krause’s guide because he explains the full process super clearly. The DX5II gives you 10 PEQ filters, so I show you how I limit REW correction to fit that, then manually copy the filters into the Topping app. After calibration, the Focal Shape 40s came alive—more jump, more confidence in translation. My long-term take: it’s a killer price-to-performance DAC/amp with DIY-style calibration, but the software controller (especially on Mac) can be the weakest link, so keep your setup simple and don’t overcomplicate custom modes.