The 20.7s can do base very well, however, it takes an amp with a really good power supply. I have experimented with many amps & configurations over the years and every upgrade paid off, some of them surprising. You mention that you have a 150 hybrid amplifier (integrated), unfortunately, that is not going to be enough to push the 20.7 base panels. When I first got my 20.7s (replacing 3.7s) I had a Mcintosh 452 and thought that would be plenty of power, it wasn't. I next tried 2 MC601's which were pretty much the same as the 452. While I had the 601s I ordered a Sanders Magtech and set it up to compare. The difference was unbelievable! There was the base I had been looking for along with everything else, the Magtech completely blew the Mc's out of the water in every way. I have another friend who also has 20.7s and loved the Mactech on my system so much he got one too. Give Roger a call and try one for 30 days, you won't be disappointed.
Brett
Brett