The Classic X-LS parts kit as well as all the other AV123 parts kits that Danny is presently offering perform extremely well. They sound great in stock form, but if you really want to take the performance up to a higher level, just swap out the stock crossover mylar capacitors with Sonicaps and install No-Rez on the cabinet interior walls. With the upgrades, the performance level is not quite as detailed as the GR Research N series kits, but is very close, especially with the Encore series Peerless India tweeter. I don't know of any other speaker kits presently available anywhere that offer as much performance for the buck as these. A truely fantastic bargin in audio.