I have owed a pair of Spendor SP-1s since the mid 1980's. I love their midrange, midrange, midrange. I am considering changing. I want an enhanced low end, and more holographic soundstaging. Any suggestions? I am driving them with a PrimaLuna Dialogue II Integrated amp. Source is a Qsonix Q 110 music server through a Benchmark Media DAC 1. My budget for new speakers would be around $4,000 USD. I like buying used equipment. I would LOVE to hear REG's opinion.