Are you buying the right interconnects ?

In the late 90's I purchased a pair of Paradigm Active 20 speakers from Definitive Audio. Prior to buying I purchased a 3 meter pair of MIT interconnects from Audio Advisor. Regular retail price was $700 and they were on sale for 50% off. 
Hooked every thing up and waited a month for a full burn in. Wasn't satisfied. I thought, whats going on here? So I decided to try the Paradigm stock interconnects that came with the speakers. They were twenty feet long and looked really, really cheap like you find in a department store. They cost $20 a pair. I switched them out and was blown away.
The sound from those 20's suddenly sounded, rich, full, very sweet top end and the bass sharpened up to complete focus. I called Paradigm and spoke to an engineer and asked why the sound difference? He said the MIT's are not a match since they are a high impedance/capacitance cable and it has nothing to with the price. He mentioned the impedance/capacitance value numbers vary with different brands. He said you should always talk to the engineers at the amp/preamp companies, and ask which cable values would best match their components. Once you get the specs, go to a local electronic supply house, the one's that sell cables to TV station's and radio station's. Give the measurements to the salesperson to find a match and your good to go.