1st post, made an account since i noticed this topic. GR isn't really new as there have been guys doing this sort of thing since at least the 70s. my mentor {glenn phillips} was one of them who ran a business out of his house in the 80s creating speaker kits, crossover design etc then later went on to work at klipsch and phoenix gold. maybe 10-15 years ago another guy everyone called zaph was doing speaker kits and selling online and at madisound. i had the chance to demo one and it was terrible. others may be decent and this is the nature of kits and speaker building. you guys may notice a theme with GR and that is no matter the speaker it always needs upgraded caps, coils and resistors, naturally he sells all the above along with the design work. another thing worth mentioning is his measurements are, near as i can tell probably 1w1m unless stated otherwise? how a speaker behaves at 1w is night and day different than at 100w. room size, material, it all plays a part. in the GR videos everything supposedly benefits because of how he measures it. it some cases it certainly might but it's not a universal equation. like many of you i'm sure i have tried various brands of caps in speakers and some do improve the sound, others do not. crossover redesigns are even harder because doing so often trades one issue for another. on some lower cost speakers the biggest benefit for your dollar imo is moving to a better cap in the tweeter circuit. what's "better" that's for you to figure out by listening. what really got me was when he wrapped on the dynaudio special 40. that's just an outstanding bookshelf. could it be improved? perhaps but dyn tests a lot more than 1w1m response curves so i really have to wonder what this speaker is doing playing music at 100w with his crossover. the guys at dyn are such fanatics they actually listen to how different glues sound before a speaker is green lit for production. however the GR reply was the same as all the other videos. we will make you a new crossover with these here parts and at 1w and a signal tone it will measure flatter. will it sound better? who knows but that isn't his business. selling you parts is.