Hello happy Tesla owners (will join in June - can't wait). I know there are already many threads about Premium Sound VS Standard Sound. This is why, in this thread I would like to focus on Premium Sound only. Not debating whether it is worth upgrading or not. I would say I have a fairly good experience about what hi-fi sound can be. I am a long-time Hi-Fi enthusiast, have a deep-in-the-5-digits-range set-up at home and owned several cars with high end sound. For most Hi-Fi enthusiasts (including me), premium sound is not about booming sound but immersive and true-live sound. The absolute set-up would be the one where you cannot tell anymore if the band is playing for real around you, or if it is just your set-up playing. It is also very important that you cannot tell anymore where the speakers are - they have to completely blend away. With closed eyes it should become impossible to tell where the speakers are with a true hi-fi set-up, when you are in the sweet spot. Well, now, back to the Tesla hi-fi premium sound, using uncompressed hi-res flac audio files on USB key. Of course, I understand a car hi-fi set-up can not beat a premium home set-up, nor can a 2.500 € car set-up beat a 10.000 € car set-up. But still... To my ears, the Tesla premium sound is not immersive enough. I hear way to much the sound coming from the driver side speaker, and from the front in general. For testing purpose, I played pushing the sound into each corner of the car. When the sound is fully pushed to the back speakers the problem seems quite obvious. The sound is very weak back there, even when pushed to max volume. Again, I am not talking about booming sound, but all-range sound. And I am not talking about lound sound neither but good balanced sound. This is to the point where I am wondering if the back speakers are working or are defective, or are they massively underpowered ? I feel a very obvious Front/Back Balance problem. Is it just me, or was it a bad car (I did this test in a demo car - my S85D will be delivered (with hi-fi sound) in early June (in Europe)). Have I not played enough with the settings (I have played quite some time though). Have I not found the child protection back sound security switch level ? Is this better in more recently built cars (some components changed in stealth mode) ? Will the new Codecs change something (I guess not, since it was a stereo recording so the codecs are not involved in front / back distribution) ? I hope it was just a defective car. Do you experience the same thing (Try maxing rear volume, compared to front).Or not ? Thanks a lot. Of course, I am still very enthusiast about the car in general - and the wait becomes exponentially painful. But obviously... this sound thing bothers me somehow.