Hey everyone. I've just finished building an EBS allignment shiva and while im generally pleased with the results, there are a few things I would like to ask. It seems that the bass is a little muddy, or boomy. Im using an AVA250 plate amp with the crossover set to just over 60H. The signal im feeding it is not coming from a sub out on the receiver, but instead from the pre outs on 2 channel stereo as im using this sub purely for music. Im wondering if this could be the main cause? The box turned out extremely sturdy as ive made it out of MDF and glued/screwed together the final product. The thing im worried about, is I lined the walls with polyfill sheets and wondering if that could the degrade the quality of the sound. On a related topic, I tried wiring the sub voice coils in parallel for a net result of 4Ohms, but found that simply hooking up one voice coil for 8 Ohms seems to yield better results. Not in terms of loudness, but in quality. Again, is it just me, or could there be a reason for this? Any thoughts are welcome.