Lately I have been looking into buying a new Eden D410XLT cab for my Eden WT550. My current set up is a Fender P-bass (passive) into the WT550 into a D210XLT and a D115XLT. The 210 says that it has an impedance of 8 ohms with an RMS of 350 watts. The 115 has an impedance of 8 ohms with RMS 400 watts. The head says it puts out RMS 300/500/750 with a load of 8/4/2 ohms, respectively. My problem is this: the 210 speakers crease and "fart" when my gain and master are each at only 50% on many notes on the E or A string, and I keep the low end EQ at a reasonable level. It sometimes occurs with the 115 as well but not very often. I want to be able to achieve the louder volumes that my amp can provide, but the cabs seem to be limiting this. When I play into both cabs, the total load on the amp would be 4 ohms (right?), so each would be experiencing 500 watts, or is this incorrect? If this is the case, neither cab is rated to handle 500 watts. However when I play with just the 210, the load should be 8 ohms, resulting in only 300 watts, which should fit in the 350 watt limit, however the same creasing and farting occurs at about half gain. If I were to get single D410XLT cabinet rated at an RMS 700 watts, would using a 4 ohm or 8 ohm model solve this problem and allow me to get louder volumes?