suggestons on speaker cable that boost mid and upper bass

Bigdish, you didn’t mention what your budget is, however Siltech Royal Signature series cables have good bass. Wojciech Pacula noted in his review of the Siltech Ruby Double Crown power cable for Enjoy the Music that they "slightly highlighting the frequency band around 100 Hz". From my experience, the same should be true of the Royal Sig series speaker cables.

Also, the Royal Signature series cables sound warm, harmonically rich, quiet, resolving and very smooth. Tonal color is just right and not over-saturated. Plenty of meat on the bones if you’re missing that with your current wire. Build quality is also superb, though make sure you buy from an authorized Dealer as there are plenty of cheap Chinese knock offs on Ebay. There are a million other cables out there, but I can give them a qualified recommendation.

Thank you melbguy1 for your kind suggestions. Sorry I forgot to mention my budget. I have no experience in Siltech cables, but my budget is only about 6000 dollars, but I would rather not to spend so much if possible, The Royal Signature is just too much for me. I have heard many many good things about Siltech cables. 

YW. Within yur budget, you could pick up a pair of either single wire or biwire Cardas Audio Clear Beyond cables around $4500. Those cables won Stereo Mojo’s ’Maximum Mojo’ award & should give you the qualities you’re after. This biwire pair are new and the guy is also offering free insured shipping in the US & will carry the Paypal fee - https://app.audiogon.com/listings/speaker-cardas-audio-clear-beyond-2-5m-speaker-cable-bi-wire-new-w... I did see another pair of single wire versions in mint condition with free shipping also.

Since you are happy with the highs and design of the Connex, I suggest you research ICs that have the characteristics you seek. Don't dismiss what a change in IC's can add. It could fill in the mid and bass.
Possibly the Cardas Clear Reflection.