How high end must your system be...

...for you to be able to notice the differences different cables will make. I've always said that I have ears of tin until a friend of mine came to my house and said that my system was just not high end enough to be able to hear the differences different cable will make. My system isn't the newest but it wasn't that cheap. My system is valued at several thousand dollars and I don't think I have anything in my system that you can find at just any audio store.

So, how high?
Rather than tilt at windmills, it may be better to list the items that comprise your system and go from there.

In general, well designed power supplies and an overall low system noise floor will reveal differences in wire.
My first system that lasted cost about 4k(1990 dollars, some were demos), a Conrad-Johnson MV-52 amp, Pv 11 preamp, B&W matrix 804 speakers and a Sonograph SG3 turntable, arm and cart all included plus cables. On it, differences in cables was easily heard. Was this high end? It made music for me and improvements have followed. As more than one person has said on this forum, if you can't hear the difference it may not be there. So, maybe you have just lucked out and have a room and system that match well enough e but one that just works. What more can one ask?
I think your friend probably reads way too many audio magazines, and was trying to impress you with some foolishness he just read. Why not try this instead, invite your neighbor or the kid next door over to listen to the rig using their favorite CD's or LP's, all the while switching cables back and forth to elicit a comment. I think you'll receive a much fairer and objective answer to your question, IMHO.
If you spend enough money on cables ($1000's) then you WILL hear a difference - it is quite simple - that is how it works. Doctors call this a placebo effect. You can look up the "expectancy effect" on wiki.

Another explanation is that some systems are faulty enough that simply unplugging a cable or disconnecting same can cause a change in response. The ground loop is a common example of this - many systems suffer from ground loops and disconnecting a cable and connecting another may have marked differences.

Finally, some cables are designed to act as filters and may have active components in a box that forms part of the cable - these will indeed make a significant difference to the sound - so would an EQ.
Gee, I can tell differences between wires I don't even want to tell in systems that cost as little as $1K or so. For example, I find some cheap cables sound much better or at least as good as some expensive ones I have already bought. And sometimes some expensive cables I have not bought yet (or actually could not buy) sound better to me in demos than the less expensive ones (I can buy). Furthermore, reviewers will often remark about how they have set such and such a budget piece up with wire that costs as much or more than the gear itself, and that it makes a noticeable difference. And its not just wire that can make a difference in these more modest systems, physical set up, room configuration and treatments and component isolation can all contribute to improving sound of lower to mid fi gear.

I say give different cables a try in your system if you want to with demo wires from The Cable Company and see for yourself if your "tin" ear resonates differently with a different piece of wire connecting your gear together. I like the idea of inviting the teenager from next door to see if they hear a difference, but you might also want to invite one of their parents too so folks don't start to wonder whats up with Mr. HiFi and the neighbor kids. LOL.
So, what is your system?
Despite this most recent critique of your equipment, I’d ask, “Do you feel it’s important for you to hear differences in various cabling?” OR “Do you feel you already can hear the desparities between different brands/models of cabling?”

Or is it you want to begin checking out other wires now but haven’t?

I’d recommend you simply borrow or buy some and see for yourself if you havn’t done so yet. If you have and aren’t able to discern much if any changes from one set of Ics to another, but feel all is well enough, let sleeping dogs lay.

There are folks around here who can and do spend tremendous amounts of money on equipment. Yay them. Some routinely chase something they’ll never ever find, and that’s satisfaction, for they seek something that can’t be provided…. Perfection…. Or they’re satisfaction lays on some future horizon… so the actual chase is as close as they’ll ever get to being happy with things indefinitely. And their treadmills continue to roll. Yay them too.

Then too there’s just plain audio snobbery at times or ego’s unrestrained in play now and then

Wether it’s true or not should not matter as much as if you feel otherwise..

I’d not let someone else’s ideas on how my system should sound affect me negatively. Each and everyone here who get’s involved to whatever extent they do, remains sole judge and jury on the product they’ll derive from the system they amass. INO it’s about pleasing yourself.

The answer though has to be a very relative one… a system is resolving enough when upstream or downstream component exchanges elicit marked results. Noticeable effects. Clearly. No guessing involved. No maybe’s. Straight ahead “Hey! That’s ???? than it was before”

What’s something like that gonna run? I’ve no clue. There’s a bunch of variables. A bunch. Like Tvad said initially, the noise floor is a big part of it. The degree to which your individual items are resolving and capable of rendering the signal accurately. Your room. Your own hearing! Just how revealing are the loudspeakers?

I’d concentrate on putting together something that I like the sound of for me…. And be less concerned of what some other’s might think about it.

I’m not being callous or telling how to do things I’d not do myself. It’s just that there’s a whole bunch of very good equipment available to us these days and for not tons of dough, it’s not hard to create a rig which does right by music. I’d bet too your’s is pretty good already and you enjoy it frequently.

Always let your own ears decide. It’s a simple matter to find out too… simply try some other cables now and then at your liesure. Enjoy.
Three variables that haven't been mentioned but I think are significant:

1)Recording quality -- the greater the realism of the recording, the easier it will be to perceive differences in cables, as well as differences between other components in the system.

2)Cable length -- the greater the length the more likely it is that differences will be heard.

3)Component output impedance -- for interconnect cables, higher output impedance of the component driving the cable will increase some cable effects.

-- Al
Using Zu Wax Biwire cable ($1000+ new, bought used at $400) on sub $5000 systems did not reveal notiecable difference from $100 single wire from Signal cable.
My current system (amp, preamp, cdp, turntable, speaker) is a bit over $15,000 (if bought new ;-), and I start feeling some differences. The biggest difference was with ClearDay shotgun silver speaker cable ($240 new). Brighter and more detailed sound. (Some may not like it though.)
However, I still havebn't noticed any significant differences, if any, among several sub $200 cables (power, IC, speaker) I've tried.
A fourth factor that I should have included in my previous post:

4)Speaker impedance characteristics and sensitivity -- everything else being equal, speaker cable differences will be increased if the speaker impedance and/or the speaker sensitivity are low, and/or if the variations of speaker impedance as a function of frequency are greater.

Some speakers are more "revealing" of differences in speaker cables not because they are necessarily better, but because they have these characteristics.

-- Al
Lots of factors that high end the system is is probably not a determining factor in of itself, though better systems will probably reveal more differences in general.

Try it yourself and see. You do not have to spend a lot to experiment. Start with vanilla stock RCA ICs and basic copper zip cord speaker wire from Radio Shack. Then try a few low cost alternatives that might make a difference. I'd switch ICs first before speaker wires. Try a used pair of MIT Terminator ICs. These should cost less than $50 and the difference has a good chance of being audible. If you want to go a bit higher, try DNM reson ICs, probably less than $100 used. I'm you can search other threads here on Agon and find lots of other recommendations to consider as well if you like
Speaker cables would make a difference on mid-fi systems and up, with proper equipment set-up. In my experience, more likely changing the sound signature and adding a flavor, similar to equlization. The biggest difference I've discovered though, was in power cords, primarily with tightening bass frequencies and adding (or detracting) music body weight
Don't be suckered into the 'high price better system'. Read some of the 'audio critic' stuff as putting sanity into the hobby.
Gee, i just blew the cost of a nice new car on my new rig..
...and speaker cable: Hmmm $2.50 YES TWO DOLLARS and FIFTY cents. eBay MIL SPEC silver plated 12 guage Teflon insulation wire (From Grumman.. prolly for a F-22!)
Anyway i bought a LOT of this just to have around for those "wire moments" and decided to wire my Maggy 3.6 with it. @ $0.25 foot times 2.5ft stereo pair that's $2.50.. of course I can SPLURGE and biwire.. Whew!! That's five bucks.
And it sounds really super fine.
(On the other hand I bought a new Kimber 7 meter Hero for the pre to amp for $750.00)
Above all else.. you gotta use your ears... AND what's BETWEEN your ears.
Match - Like knownothing, I readily perceive an upgrade in cabling on my mid-fi second rig. The answer to your question is yes. If you are using OEM interconnects, by the way, spending $50-75 on a lower-grade name-brand ic will probably be the best $50-75 audio purchase you'll ever make. That first step up is dramatic.
While you are at Radio Shack picking up the zip cord Mapman suggested, also buy a set of their Auvio interconnects. Very nice sounding for under $20, compare favorably in my experience to wires from usual suspects that cost more.
I changed the interconnects and speaker cables in my midfi system that I have in my office and I can hear a difference. The system has captured power cables, so they remain. In all, this setup costs about $1,000 - $1,200, so I don't think a system has to be "high end" to hear differences in cabling.
The first set of upscale cables I bought were here were Cardas Neutral refs. About $270 or so. Like their name indicates, they are pretty neutral. A good thing to have as a main IC when stepping up things elsewhere. I then bought one more set.

Thereafter, it was power cords.

It was when I bought a set of pretty good speaker cables though, that everything began to get squared away. I still have the SR Sig 10s running my main speakers. From what I’ve seen so far, it’s going to be a pricey affair to improve upon them, but I will at some point.

Once neutral signal cables are in place, power cords are key.

At that point, you should be able to discern readily other changes in your system… given the parameters Al pointed out.

A reference is a prerequisite in order to step up. Crazy $$$ doesn’t have to be spent all the time either in order to achieve such a situation.
Usually super-bright systems will be more revealing of cable. Then the stereo mags brag about how the speaker is EXTREMELY sensitive to cables, amps, etc.

Disclaimer: This is a generalization.