I've used Radio Shack cables all my life. The better ones, the thicker copper ones I believe they are. I was quite happy with them really. I didn't really believe in all the cable hype. Cable is basically cable.
Then I found a used, but in 'excellent ' shape, pair of 'very rare' Sansui, 1980, 'special order' only, "High-Efficiency Cable", thick black jacketed with shielding and 'all that stuff', for my vintage speakers. Later on I found out they were designed like professional 'broadcasting' type cable of the period. Cost me $10 plus $25 shipping for 2 each/23 foot long cables from Ireland. Took 5 weeks & 6 days to get. British Royal Mail is beyond slow, international mail anyway. I though they were lost or stolen, I entered into a controlled 'freak-out'...I really did! I really wanted these specific cables!! Then they finally arrived. Total Relief. (Lesson Learned: Never ' Ever ' be in a hurry with Royal International Mail!!!!!!!!

)
I hooked them up and it was like an immediate 'WOW'! Substantial difference in sound quality. Easily heard and very noticeable (for the better)...no going back now. I was totally wrong.
** As
Steve Hoffman (professional mastering and sound engineer) stated: Use quality vintage cables for vintage stereos because that's the cable the speakers were designed to use. ** I took his advice and it sure worked for me! Perfectly. I was amazed, really, from the moment I connected them and turned the stereo on. Maybe it is 75% mental. haha. Who cares, these new cables sounded GREAT!!!!!!
So I searched "Hi and Low" for another 'same exact' pair, in 6 different countries... d a i l y (USA, Japan, England, Germany, Italy, and Argentina / sometimes Singapore and Taiwan too.). It was like "Mission Impossible"...for 5 years. Then a Brand New NOS/NIB pair 'popped up' on USA eBay (of all places - Never expected THAT to happen - I don't believe that they were ever sold in USA). I just couldn't believe it. I totally freaked, I was shaking!!! I went into the Panic Mode. I bid $375 on them, and held my breath, just to make sure I got them, and got them for $130 plus $25 shipping. (A military veteran bought them new in Japan back in 1980, brought them back to the states, and never used them or even took them out of the box.)
Happiness is having a pair of speaker cables you really LOVE the sound of !! That's an ABSOLUTE.
So I guess quality interconnects would make a big difference in sound too. I CERTAINLY would imagine so. Speaker cables sure do!
Anyway...that's my cable story.