Picked up this Yorkville xm100 last year cheap but never really did anything with it till recently. The thing is it sounds pretty awful and I'm not sure if it is a bad amp or a bad speaker or both. I ran the amp through another 4 ohm speaker and it sounds bad at low levels and gets worse as you turn it up. I hooked the speaker up to my musicmaster and that sounded bad too. I didn't see anything obviously wrong in the chassis but then I'm no electronics expert and don't know how to test components. The speaker is a 15" Eminence 7347 4 ohm 200W, 67-0310A 0095 I think that means it was built in 2003. Anyway if they are both bad I was thinking I could get a new 8 ohm speaker and use the combo case as a cab. Is that the best way to get something good out of this? I used the speaker out of this Gemini GX-450 to test the amp out. It turns out that if I run my bass through my little Mackie mixer and into the GX-450 it's a pretty good bass amp. Turn the volumes more than halfway and it is seriously loud. And it doesn't sound crappy. I am actively researching bass amps at the moment but this will get me by for now along with my musicmaster. Feedback?