Looking at speaker options for a US made Red Stripe Peavey Envoy, which comes with a 6 ohm Blue Marvel. The amp is 40 watts, solid state. After inquiring with Peavey about ohm requirements, I received the following response, which I thought others might find useful as well: You can consider a 6 ohm speaker to be a 8 ohm one. The nominal impedance of some 8 ohm speakers is 6 ohms. Conversely a 3 ohm may be considered a 4 ohm. It's alright if the speaker has a higher power rating then the amount of power produced by the amplifier. In fact it is desirable. So, it should be at least equal to or greater. Classic guitar speakers are typically rated at 50 watts ( Celestion Greenback ), 60 watts ( Celestion Vintage 30 ) , 75 watts ( numerous Peavey speakers such as the one used in the latest Bandit 112 part # 30777410 ) &, 80 watts ( Peavey Vypyr 120 speaker # 30777451 ). Higher powered amps have to use special higher power rated speakers. Generally speaking the higher power rating a speaker has then the higher the sensitivity rating it has also. So, if the difference were great enough then the higher sensitivity may not be as loud as the lower one with a given amount of power ( bot possibly louder with maximum rated power ). But you should be able to use a 50- 80 watts speaker without a problem ).