Actually the Roksan Caspian has great low end. I have owned two units and the bass definition was certainly a strength as was it's authority. I compared it to a Plinius 8150i and SimAudio I-5. To even make a comparison with an amp quite a bit cheaper is a compliment to the Caspian. It's weakness is a lack of insight and transparency. It's not quite as rich or open as the better integrateds. You will do well to get a speaker that can also reproduce that bass. The Monitor Audio S1 has the best low end I have heard near the price and is fast as well. I use a set with an Exposure 2010 and they fill in the low end very well even when my sub is not on line.
Best of luck!
Best of luck!