Need advice on how to sound insulate my room

Need advice on how to insulate my stereo room. My rig is is in the finished basement of my home. Problem is that the house is old'ish and the sound reverberates throughout the house - probably through the basement drywall and ceiling.

The upstairs floors are hardwood, with throw rugs. The walls are plaster on lathe.

The basement ceiling is drywall. However, the ceiling height is only about 8 feet, so a drop ceiling is not an option.

Not sure there's much I can do, but any suggestions have to be aesthetically nice or my wife will object.

Adding drywall and green glue (or liquid nails) may help with some of the problem, but the deeper bass will probably continue passing through the walls and travelling to the upstairs via studs, etc. You just can't practically add enough mass to attenuate those frequencies. If you're willing and able to do it you might look into resilient channels that act like shock absorbers between the drywall and studs, beams, etc. Again, the Geddes book I mentioned earlier does a good job of explaining this stuff.
Green glue plus the extra drywall will really help with everything but the low base. The "glue" name is misleading. It really does work. Resilient channel is an option, but more work, plus you loss a little height. I don't believe that the resilient channel will give much better results than a green glue/drywall solution for the ceiling. You might give Ted White at Sound Proofing Company a call. He knows the details of both solutions.
Just to clarify Soix's comment - Green Glue is not the same as liquid nails. Green Glue is designed to attenuate vibration and sound by remaining in a permanent semi-viscous state unlike liquid nails which hardens (cures) completely. The difference is substantial.