biggest difference...speaker cable or IC's?

when considering changing cables will there be a better sonic difference replacing the balanced IC's from the pre and source or by bi-wiring the speaker cable? looking to mellow the highs, but retain the detail and imaging. using horns with mcintosh in a very large room. any opinions appreciated.
for horns: a networked-type speaker cable has worked out very well for me: MIT paired with classic Belle Klipsch.

Regarding conversion to biwire: although my MH750 Magnum's are biwire, I wouldn't necessarily expect a significant improvement in going from single to biwire with the same model of cable. Sometimes a switch to biwire is better, sometimes indifferent, sometimes even a degradation; you just have to try it.

So in this situation I guess I'd probably try some different interconnects, although not knowing about your equipment or present cabling leaves significant info. unknown (in terms of offering a worthwhile opinion).
A lot depends on which is longer. In my experience, where I have long speaker cables (25') and short ICs, the speaker cable has made bigger differences. Also, the purpose of balanced ICs is to cancel out the effect of the cable, so the balanced IC is probably pretty good, and not as likely to yield as much improvement.
Unless your current cables are somehow pretty deficient I don't know that you'll hear much real difference. For starters, I'll cast another vote for leaving the balanced ICs as-is - unless they're actually coathangers you're unlikely to find significant improvement there.

Bi-wiring? Well, if you're not going whole-hog and actually bi-amping, then that's probably not the answer you might think it is (unless you just wanna buy more wire ;~). And please don't take my opinion - you can read a fairly plain and pointed "what cables" page from a fairly popular purveyor of decent wire and see what they say at: Cobalt Cables. No, I'm not associated w/ 'em in any way - I just find it refreshing when a cable manufacturer tells the unadorned truth.

And buying cables to tame your highs? That's realy using wire to be a tone control, and that's the proper job of the electronics. If your pre-amp isn't doing the job for you there, then maybe it's time for a full-fledged equalizer - and you can get one heck of a higher-end equalizer for less that the price of a pair of MIT Magnum bi-wires. I have nothing against MIT or buying good wire, but I just think it isn't the job of speaker cables to color or change the signal - exactly the opposite. And maybe an equalizer isn't even needed here - maybe just tuning/tweaking your speaker placement and the room (treatments, etc.) could be a better place to start to fix those highs? Good luck!
thank you for the responses. i have an equalizer on the mc c42 and use van den hul speaker cable(17ft run) room is large and irregularly shaped(about 700 sq. ft.) lots of glass and also soft surfaces. my grado rs2 headphones have good sound with no harshness, but my horns do set up some harshness to my ears. the cdp is mc mcd 205 and the amp is mc mc202. i have equalized the output somewhat to little effort. i use the 40hm taps. it is not a huge problem, but on certain recordings a harsh resonance sets up in my inner ear that can be annoying. i listen to c-jazz mainly and find the problem occurs with trumpets and a voice like dianna krall. when i changed to vdh cable it helped alot and repositioning the speakers and adding spikes helped somewhat. it is very close to being correct so i am looking for that last piece of the puzzle. i do not wish to replace the electronics so maybe the speakers are a place to look. finances dictated the speaker(klipsch rf-7) and also room size. they are used for HT as well and seemed to be a good combo for both(although not perfect) most speakers were not able to fill the room. tried sonus faber,jm labs chorus, def tech, and maggies. i think i can be pleased with the set up with one last tweak if i can find it. thank again for the excellent responses.
Hello Knorman,

For me the biggest difference (read improvement) resulted from installing better speaker wires. There is something to be said for sticking with one brand and model of wire throughout your system. Mixing brands and models is usually going to screw up the time domain while it "fixes" another problem (like "it's too bright sounding").
When I installed the same brand and model (Purist Audio Design Proteus IC and Speaker Cable) my system told me right away that I it liked the new speaker wires. I have since changed some of the pieces and no longer use the Proteus speaker cables, but I have heard it more than once where keeping it all in the family makes it sound better.

Horns can be brutal because they are so efficient relative to other drivers. You should definitely look into the room treatments...but before you invest in an equalizer, you should look at the crossovers in you speakers. Odds are that they would benefit from an upgrade of the coils, especially on the woofers. New coils (the bigger the better) from North Creek Music Systems will not cost you anywhere near what a set of speaker cables (good ones) will. You might want to think about bypassing the caps with some high quality capacitors on the horns while you are at it (go to for a real good assortment; click on capacitors and then look on the bottom of the page for all the different brands). That might be the best approach to start with.

One more tidbit and then I'll let the real experts come to your aid. Try to find out what kind of wire the speakers are wired with. As Apogee fans know, the Symo works better than just about anything out there on Divas, because they are internally wired with it. If you can buy the same brand and model of wire made up as speaker cables, then it will be hard to improve on.
Kimber 8TC or other braided teflon-coated speaker wire is best for long speaker runs. How is your van den hul shielded from RFI?