So a while ago I paid GR to “upgrade” the crossover in an SVS Ultra center I was using for a bit. I asked him for before and after measurements and nothing ever came of it, once I got the speaker back the crossover was definitely modded but it’s response was identical to its OEM performance. Before I did the crossover upgrade, I was 99% sure it wasn’t going to make an audible difference and in terms of his videos of course the guy who runs the company is going to push the products he’s selling. But I’ve never seen any sort of tangible evidence his upgrade kits do anything other than continue to fund his campaign of nonsense. I believe GR was the OEM source for AV123 before they went under and years ago I went to audition a pair of their towers and that giant RS something center channel they made, however for the price they just didn’t cut it. You have to figure most of us on here are here because we want to increase and/or share our knowledge of home theater and loudspeaker setup, design, tweaks, etc but the majority of the users on here require quantifiable proof of any sort of mods or upgrades as should any consumer involved in the A/V world. Unfortunately there’s so many uneducated buyers out there that I believe we’re actually the minority. I’ve got the REW graphs and pics of the SVS before and after somewhere and if I can find them I’ll upload them, still working on making some graphs up for the MultiEQ-X & Audyssey App/Rat Buddy app comparison.