I bought an Ashdown Blue 180-15. I am thinking about getting an add-on cabinet, maybe a 2-10 or a 4-10. Thats the easy part. Knowledge is the trick....and I'm runnin a tad short. In the specs, it states that minimum output ohms for an extension cabinet is 4 ohms. Could someone look at the specs, at http://www.musiciansfriend.com/product/Bass/Amps?sku=485037, and tell me if I should get something like THIS? Its 8 ohms. Thats more than 4 ohms. Is that in line with "a minimum of 4 ohms?" I'm a tad in the dark here. The 180-15 has two 1/4 jacks in the back. One has the cord from the internal speaker plugged into it, the other is for an extension. It says 'external speaker minimum 4 ohms. How many ohms is this amp? Will any cabinet with more than 4 ohms work? 8? 16? What would the difference in the sound be. depending on putting a 4 or an 8 ohm cab? An yone with patience, and a basic knowledge of electric circuitry.......help. Gimme a twenty words or less (just kidding) tutorial on this PLEASE... orrrr, should I get a higher watt amp w/ 4/10's, and use the 180-15 as an external cab?