Help with first cable upgrade.

If your on a tight budget and your system is a little bright the Canare bi-wire could work well. 10 foot speaker wire would run $20, make some interconnects out of there microphone wire and switchcraft rca's for $2 a piece from B and H photo for dirt cheap. Make power cables out of there speaker wire just use 4 conductors or 1 or 2 cables for each run and higher gauge for the ground and some cheap watt gate ends. There is a 8 meter pair of Grover Huffman FX plus balanced interconnects on Audio Circle for $100 buy it and cut it up you could make a power cord and a few interconnects. 

Performance Audio is the cheapest on Canare 4s11 bi-wire speaker wire I've seen at $1.16 a foot with free shipping UPS with a $20 purchase, don't know how they can do that and make a profit. 

If your speakers are a little bright put some felt double taped around your tweeters. Cymbal felt for cymbal stands from a drum shop work well cut into 4 pieces, may look funky but can break up aggressive beaming  highs and it's cheap.

OP if you can solder great, if you can't you might have fun if you learn how. Google " silver signal tape interconnects. You can build a interconnect for under $20. I ran across this article  20 years ago and this is what made me buy a soldering iron and learn to solder. These packing tape interconnects sound very good for what they are. I started out with using copper magnet wire for a $10 an interconnect pair, then bought some silver wire and cost went to maybe less than $20 per pair. I would guess they can sound as good as $200-$300 cables. From there I built much more exotic cables but it's a good place to start. The cables in my system are all store bought but are just stupid money but on a budget you can't beat diy interconnect and power cables.