I am preparing to order a SVS sub 25-31PCi or 20-39PCi and need a little advice. My setup is as follows: Marantz SR-19 Paradigm Monitor 7s,cc-350,ADP-170s,ps-1000 I do not have an external crossover and have read here that ALL Marantz receivers's crossover internally at 100hz. My SR-19 manual doesn't show this specification but it mentions that setting the speakers to SMALL routes bass lower than 80hz to the sub. This leads me to belive its set at 80hz but I don't know.... This is where I need to decide which size sub to get. I read that the 25-31 will sound better at above 80hz than the other. I know my ps-1000 even sounds really boomy at 100hz. So I'm leaning towards the 25-31PCi. But, after hearing the phantom menance on some subs much better than mine, I want to go lower than 25hz. So, should I choose the 20-39? Now, what about getting the 25-31 tuned to 22hz. How has this worked for some people?