Amazon.com: CQRobot Speaker 3 Watt 8 Ohm Compatible with Arduino Motherboard, JST-PH2.0 Interface. It is Ideal for a Variety of Small Electronic Projects. : Everything Else
Speaker - 3 Diameter - 8 Ohm 1 Watt : ID 1313 : $1.95 : Adafruit Industries, Unique & fun DIY electronics and kits
MESA/Boogie Speaker Impedance Matching and Hook-up ~ Part 1 | MESA/Boogie®
8 ohm LS an 4 ohm verstärker?!, Lautsprecher - HIFI-FORUM