I've been playing bass for about 6 months I have a little 50w Rouge amp and it just isn't cutting it any more. I'm willing to spend about $500. The Ashdown MAG C115-300 or the C210 looks really nice for the price. I have two questions what would be the difference in the sound between one 15inch versus the two 10inch speakers? Also could any one suggest a better or better valued amp within my budget. Thanks! 