Long ICs - A'gon versus Audiocircle

Tony, it depends on the output impedance of the source. You will have roll-off issues only with high impedance output drivers.
There are other issues with long wires, which have mainly to do with noise pickup, as you know... The noise issues are much less severe with speaker cables. That is because noise in interconnects gets amplified and noise in speaker cables just loads the speakers, possibly interacting with the amp, but in general it does not get amplified by the electronics.
Short interconnects rarely need shielding for noise/hum reduction. Long ones rarely get away without proper shielding. So, lots of reasons to go with a "traditional" short IC/long SC.
BTW 12-16 pF/ft is not typical. Check specs more carefuly!

Yes, I know that is on the low side for ICs, but that is consistent with types that I've tried. The issue I have with long speaker cables is when do you go so far as to have to consider the use of a Zobel network? And doesn't that have its own shortcomings?

The MAIN reason for going with shorter speaker cables (under 10 feet) and longer ICs, is that amplifiers have a hard time excercising control over the woofer (providing good transient response/clean bass) when their damping ability is diminished by longer speaker cables. This is especially true for tube amps with output transformers (and therefore inherently limited damping ability)

ICs on the other hand can be quite long before their per-foot (possibly detrimental) electrical characteristics add up to anything significant. Using balanced ICs (XLR) pretty much elimninates the noise/hum pickup problems.

If you need proof of the above two principles, you need look no further than the pro sound world (theatres, concerts, recording studios, rtc) where these methods have been standard operating procedure for decades now.

You may use a Zobel on short speaker cables too. In theory it is a circuit that only terminates RF energy, way above 20 KHz.
Nsgarch: I don't agree with the argument about damping factor with tube amps. Most of these amps have a high output impedance to begin with and the great majority has long thin wire in their output transformer. A more reasonable statement is that long speaker cables should be made of thick (effective) gauge. BTW, that concept is also debateable, given the crossover components in some speakers.

As for balanced vs. unbalanced, not all pro audio gear is great. The requiremets in a production facility is first of all reliable operation. A "rat's nest" in a studio would be Hell to resolve without balanced wires, so sacrifices are acceptable.
That is not the same for the home system, which in many cases is much more refined than pro audio setups. That's because the home user can afford down time and fiddling with the setup with endless upgrades and tweaks and the studio engineer can't.
While touching on this subject, many people mistakenly assume that studio equipment is great for the home. The requirements of a mixing session are not to enjoy the music but to tell the miniscule details in a near field environment. There might be more rigid need for low distortion at very high SPL, which means nothing to the home user. As we all know, there is no free lunch in engineering.
The home user would do much better buying equipment designed and optimized for home listening, not for pro audio applications, IMHO.
You may have to deal with all sorts of hassles, like hum and other noise and compatibility between devices and cables, but in the end you could reach an optimal "point solution", that is really the best one can dream about in an audio system.
It's sort of like buying a Honda Civic vs. building a tuner Civic... The basic car has great performance and a warranty - it's a safe design. The tuner car may be uncomfortable and quirky. It might die at stop signs and idle rough on hot days, but in the end it will be better on what it was optimized to do - go fast or race...
The same with an audio system. You can play it safe and have a pretty decent performance, but to reach the summit you really have to work harder... With enough will and preseverence, you will eventually make it...
My very subjective opinion, of course.

Serus
Was suprised to read in Mappleshade catalog same thing that you said was "traditional" thinking that folks should use short IC paths (less distorion) and longer speaker cables.Still have a hard time undertsanding on why a 12ft run of same wire with speakers should be than 6 ft.I just assumed more wire for heat and friction to build up there as with interconnects.Me I am helping a freind set up his Magnepans and I told him that even if we went with a very cheap wire (somebody sugested Blue jeans wire and their stuff is very cheap/inexpensive depending on how you see it) .Want to use it so we can move his 2 gear racks from in between his speakers and big 40" CD storage "spinners" (set a bit back and to sides).I told him that even though one should go balanced/unbalanced/balanced to often (think I read that in /Stereophile's Hartley's book) that going RCA as ins the 30 ft or more of wire would require XLR wires-so we can open up the area around his speakers.But his amp I thought could sit on rack and I thought short run would make sense but you and others say no and I just can't wrap my head around it.I have also been told by some my idea that without some testing software or newer adjustable pre like the DEQX don't assume I'll get benefits from removing stuff but I still think it's worth the try.But again even if we use very cheap wires to do it.But why the length and how long?Are there specs I should ask from Maggie or Bryston which we are trying to buy?
Thanks
Chazz