I have a SWR Triad 4 ohm and a Hartke 115XL 8ohm I'm thinking of using together. My Eden VT-300A amp only has a setting for 4-8 ohms. If I run them in parallel that would be 2.66 ohms and if I run them in series that would be 12 ohms. Which combination and setting would work the best, or is this just a bad idea???