And on that count, let me ask, from the link, sufficient enough cables?
I looked at the link, and they strike me as a reasonable choice, at least to use initially and perhaps over the long term. I’m somewhat puzzled, though, by the references in the description to a conductor diameter of 7 mm, and an outer diameter of 17 mm. The description also states that the conductors are 12 gauge. A 12 gauge copper conductor has a diameter of approximately 2 mm, as can be seen in this
wire gauge table. Also, looking at the illustration the outer diameter looks to be a lot smaller than 17 mm, as the diameter of the tips of the banana plugs shown on the cable is probably about 4 mm, and as best as I can tell the outer diameter does not appear to be more than perhaps 2 or 3 times that amount.
In any event, while the impedance of your speakers, as shown
here, is very low (less than 3 ohms throughout most of the audible frequency range), the resistance of 30 feet of 12 gauge wire (the combined length of the + and - conductors in a 15 foot cable) is about 0.05 ohms, which seems reasonably small even in relation to the low speaker impedance. (The corresponding figure for the shorter cable would be about 0.03 ohms if you go with the unequal length alternative). However it seems conceivable that the unspecified inductance of the cable, in cables of those lengths, may be enough to present an impedance in the upper treble region that is audibly significant relative to the low impedance of the speaker at those frequencies. (The impedance presented by an inductance rises in proportion to frequency, and the inductance of a cable rises in proportion to length). The result of that might be a very slight softening of the upper treble, which in the case of the Thiels that I’ve heard and also read comments about could very well be a good thing.
And then there are the myriad other possible cable effects audiophiles like to discuss and argue about, and that are much talked about in marketing literature, but whose quantitative significance is debatable, and which in some cases may not even be quantifiable, such as "strand jumping," metal purity, "skin effect," "dielectric absorption," "time alignment," "characteristic impedance," antenna effects, etc. In any event, it seems safe to say that the bottom line on those things in any given application is unpredictability, so IMO you have made a reasonable choice. Other opinions will certainly differ in some cases.
BTW, if it does turn out that your speakers have been damaged, and if it appears that a particular driver or drivers has/have been blown, you may want to give Bill LeGall at
millersound.net a call. He is the best in the business when it comes to repairing speakers, and he is also a pleasure to deal with. Typically just the failed driver(s) is/are sent to him; shipping the entire speaker is usually not necessary.
Good luck. Regards,
-- Al