Those drivers came from Parts Express, both the midwoofs and tweeters. I think they still have some. Check in their specials listing. They're shielded Chinese drivers; some batches have Pioneer logo. The tweeters are Onkyo auto sound, they have a post for coaxial mounting on an auto driver that you chop off. I used 8 midwoofs per side as I can run 4 ohms no problem, and the 38" TL length is fine for the Fc of 100 Hz. If you need 8 ohms you can go with 16 drivers, but with an Fs of 105Hz you still won't get below 80 Hz, so you'll need a sub in either case. I use three homebuilt stereo amps for the mains and surrounds and a plate amp on my sub.