When using the highest grade cables out there, For resolutions near 4K, it’s recommended to use an HDMI cable that is no longer than 3 meters (10 feet). After that distance, the signal can start to degrade. For lower resolutions, the reliable distance is much longer, with the most common being 15 meters (50 feet). If using 4K video, that length is just not feasible. Even the audio may suffer from line resistance, impedance, and EMF noise. You would be better off with a different solution, below. Possibly using a LNA, (Low Noise Amplifier) at half the distance, as well as top grade low impedance cables. This is not going to be cheap.
Instead,send the audio down OFHC Monster cable from the output of a stereo amplifier. (Standard analog audio). It will be cheaper and more reliable, as well as cleaner audio. Put more simply, in your current plan, your recieveris on the wrong end.