Actually, it should only matter if you are going to connect more than 1 pair of speakers to the amp. Usually ... each pair of speakers that you will add will half the total overall resistance of the line and when you get below 2 ohms, it begins to get risky (blowing fuses, etc.). For example, if you have 2 pair of 8 ohm speakers connected to your amp, the line would check in at 4 ohms, which is OK. Now, a lot of speakers rated at 8 ohms are usually operating nominally at 6 ohms, so your line is really at 3 ohms, still OK. Try this with 2 pair of speakers rated at 4 ohms and you can see where you will get closer to the 2 ohms limit. Now, there are also amplifiers that can safely operate at 2 ohms. So ... if you are planning to run more than 1 pair of speakers, you have to be aware of the math. Regards, Rich