Which component upgrade will produce more BASS?

Agree with audiofeil. 8" woofers won't move enough air to reproduce lower octaves with aplomb. If this is what you're after, go for at least a 10 if not 12" woofer. I don't know what kind of midbass driver this speaker has but 8" is also too big to reproduce midbass optimally if it's pulling double duty.

I had a pair of Mirage OM7 speakers for a short period of time and I couldn't believe the amount of bass they produced. Too much for me. From what I hear, sounds like most Mirage speakers produce this kind of bass.

Agree also with Audiofeil.

This recommendation is not found in the usuall realm of tweaks but works : Replacing all the steel screws/bolts on your speakers with solid brass using a torque driver to deliver precise hand pounds of pressure to tighten up the brass. Virtual Dynamics , a Hi-End cable Co. from Canada , has a series entitiled "The Oddophile" running on AG, w/ Episodes detailing the "how to" to this tweak, as well as other speaker tweaks. The brass tweak cost about a hundred bucks, but that was because I purchased several types of hi-quality brass from a commerical distributor that only sold in bulk. The Wheeler Torque Wrench only cost $45.15 via the internet delivered.

The difference is night & day in terms of bass & resolution. Check out the video's on Audiogon. You just might try their tweaks for speakers as I have. Best money that I've spent on speakers in quite a while. This tweak may resolve your bass problem at its source - the speaker itself. All the best.