Loudspeaker wire does make a big difference.
I remember when I purchased my first set of "SMOG LIFTERS" speaker cables back in the late 1970s. They were a revelation, like getting a new amplifier. They really were not that expensive at the time, maybe $30 or so. They were a thick, fairly flat braided speaker cable with silver on the connecting ends.
Later I used thick braided flat cables from IBM which I used used for longer runs in a different house. They sounded great as well. IBM used them to connect some type of high tech equipment. A friend got them for me when IBM gave away some equipment to employees.
The speaker wires on the market today range from the reasonable to the insane. I like the thick, flat braided speaker cables just because they are what I have used in the past and they do help allot. Other wires I see I do not understand. I think spending thousands of dollars on a 10' speaker wire run is over-the-top. I would rather spend that money on a vacation.
Here you can find a picture of SMOG LIFTERS available on Craig's List.http://dallas.craigslist.org/ftw/ele/2891197780.html
"For sale is one pair of Discwasher Smog Lifter speaker cables from the late 1970s. These are somewhere between 5 meters and 20ft. in length. They are constructed of high-speed computer cable - high capacitance, 24 gauge stranded wire. Many wires are woven into the cable (sort of forms a tube) to minimize outside interference. Here's something I found on the Internet: "The flat braided design reduced inductance, so the top end was not attenuated, making the sound with some amps and speakers clearer and more open. But only with some combinations! The price you paid for the lower inductance was about 10x higher capacitance. As mentioned, some amps objected strenuously to that, so it's a try it and see proposition. However, if the amp goes unstable, you may risk blowing the outputs."http://www.roger-russell.com/wire/wire.htm
- Speaker Wire - A History by Roger Russell