Summary: I bought this receiver to replace an old Sony 5.1 that did not have HDMI. I choose the Pioneer VSX-520-K because it was reasonably priced and had the HDMI pass-through. When it arrived and I set up the system, the audio would not calibrate correctly. I can't explain it but the audio just seemed "Off". I read through the manual, made all the appropriate adjustments (entering distance of each speaker, the speaker size, etc.) and still it just didn't sound right.
Summary: I purchased my first of this receiver and found it had a problem sending any signal to the Subwoofer PreOut port on the rear panel. Pioneer tech support confirmed there was a short in that port. Receiver sent back to amazon for replacement. I got another a few days later and found that it not only had the same problem with the Sub out, inputs on the rear panel for dvd and tv did not pass audio signal so it wasn't possible to hear either of those.