I might be buying a pair of bookshelf speakers and was wondering if I'm going to be with the Yamaha RX-V383BL or should I go for the Yamaha RX-A670BL. I want 4k pass-through, HDR, and a subwoofer output in case I want to add a subwoofer in the future. The entry level Yamaha does all that and I'm wondering if I will benefit from the RX-A670BL if I'm going to use it for just stereo sound. I'm not looking for a surround sound experience, I'm just looking for better quality sound than my TV speakers and a sound bar/subwoofer combo. The speakers I want to buy are either the Sony SSCS5 or the Polk T15.