Hook-up Wire: Duelund DCA16GA vs Neotech STDCT-16 vs Cardas 15.5 AWG

I am about:
https://www.hificollective.co.uk/catalog/stdct16-neotech-upocc-copper-wire-1903mm-teflon-p-8458.html

I don't have experience with multistrand Neotech wire.

Dear All,

Thank you for your contributions to this very interesting thread. I’ve been experimenting with tinned copper cables too, mostly with the usual suspects (Duelund 16GA, Belden 9497 for speakers and 8402 for IC), but I'm still at the beginning of my experiments, so I would like to ask for some expert advice, especially in the area of speaker cables, the internal wiring of my speakers, and upgrading the crossovers. I'll proceed in reverse order with my questions (my apologies for including not just cable-related questions in this thread):

I have a pair of vintage JPW AP2 speakers, which I love. I listen to classical music most of the time, especially solo piano,and they are wonderful at that. They are a classic 2-way British design with a sealed box and fairly simple crossovers (just an air core inductor behind the woofer, in series with it; and a resistor, a bipolar electrolytic capacitor and a smaller inductor behind the tweeter (the latter in parallel)).

I've decided to rebuild the crossovers to improve the sound.

1. Concerning the mid-woofer: the AP2 comes with an air core inductor that is 1 mH, 21AWG, 1 Ohm. Many people suggest that an inductor of the same inductance, but using a heavier gauge wire could be beneficial. But since it also results in a smaller resistance, would I need to compensate for the drop in resistance by installing a resistor in series with the new coil? If so, what are the possible benefits of giving up the principle of simplicity in this case (that is giving up using only one part in the bass crossover section, i.e. the coil, vs using two: coil + resistor, where presumably the two parts have their own kind of distortion, even if you invest into a really good resistor)? Or shall I just leave the original part?

2. Concerning the tweeter: does the thickness of the wire used in the inductor in parallel with the tweeter matter as much as that of the inductor in series with the woofer? The current part is a 0,6mH, 29AWG, 3.18 Ohm (air core). Would I gain anything by replacing it with a heavier inductor (+ a resistor)? As for the cap and the series resistor, I think I'm already settled, it's just the inductors that give me a headache.

3. Internal vs. external crossover: once I am there to rebuild the crossovers using better quality parts, I might as well just move them out to an external box, thereby distancing them from the vibrations of the speaker (it's not much extra work). Is it worth - sonically - to do so, or do internal crossovers perform reasonably close to external ones using the same parts? People seem to be divided on this issue (what a surprise :) ), but Living Voice (which you discussed above) advocates the use of external crossovers, if one can afford them. Again, since I would do the work, it's not much extra work or cost, but I understand that the AP2 might be too modest a speaker (especially compared to the Living Voice) to display the difference between the crossover built in or outside of it, so I might not gain anything.

4. Cables. Internal cables first: would you upgrade the stock internal wires of the speaker with different gauges for the tweeter and the woofer? I am thinking about 3 possible combinations, only one of which uses wires of different thickness for the tweeter and the woofer; and while I know that it is impossible to tell a priori which of the 3 would sound best in my speakers in my room, I will ask the question anyway :) Would you recommend Duelund DCA16GA tinned copper for both tweeter & mid-woofer, OR Duelund DCA16GA for tweeter and DCA12GA for mid-woofer; OR 20AWG CC08 solid core Duelund non-tinned copper cable for both tweeter & mid-woofer (in general, I am a big fan of solid core cables, and I love the IC I built of the Duelund 20AWG CC08, I can highly recommend it!). I am not considering the DCA20AG for the tweeter, because I like the fuller character of the DCA16GA which everyone tend to associate with it; if it is 20AWG, it would be Duelund's solid core copper cable. @grannyring suggests to "at least match [the] gauge thickness" of the inductor when choosing the wiring. If I stick to the original 21AWG inductor, then this is really not an issue, as you can see, only if you say I should use a much heavier coil.  

As for speaker cable, I am thinking of replacing my current DCA16GA with the DCA12GA, following @grannyring 's advice above regarding the choice between the two in relation to the power of one’s amp and the sensitivity of the speakers (my amp is a 35W solid state Audio Innovations ALTO mk1; the AP2’s sensitivity is 89db).

Now, if you suggest I should I also opt for an external crossover, that would multiply the possible permutations when it comes to speaker cables; you could use e.g. a single wire from the amp to the crossover, say Duelund DCA12GA, then DCA12GA from the crossover to the mid-bass speaker terminal & DCA16GA to the tweeter, and finally 20AWG solid copper core everywhere inside the speaker (it's a pity this solid copper wire is not very practical for speaker cable because of its rigidity). Or would you rather use the same wires all the way long from the amp to the speaker drivers (e.g. bi-wiring all the way long with DCA16A & DCA12GA)? I guess I could even let go of the speaker terminals, and solder the chosen cables directly to the drivers and the external crossovers’ output, sealing the speaker cabinet from behind, and just drill a hole for the wires. While this may not be very practical for many, for me it wouldn't be a problem, and I could avoid the use of binding posts which – I assume – have their own sonic imprint.

Apologies for the long entry and the numerous - not necessarily related - questions; I hope the answers will serve others as well. Many thanks for your advice in advance.

Point 1: Those are budget speakers so expect budget components. Stay 1mH but upgrade to 18 or 16 AWG air-core. Look for a coil that has been dipped or uses baked varnish. Do NOT add series resistor. The bigger 16 AWG will have a lower resistance, improving damping factor, and the baked varnish provides a more stable coil.

Point 2: You can keep the tweeter coil/inductor as is.

Point 3: External XO is superior. I like to build on phenolic resin board or Bakelite and rest the XO in a shallow box filled with dry builders sand which will rest on the floor directly behind the speakers. Make the box 10mm wider and longer than XO board dimensions and settle the XO board onto the sand. Experiment with feet underneath. Spikes do not seem to help much. I preferred squash balls cut in half or better still are springs. If carpeted then place a heavy porcelain tile underneath.

Point 4: I now only use solid OCC Cu for internal wiring. About 24 AWG for tweeter and 12 to 16 AWG for bass. I would solder the big 1mH coil directly to the speaker terminal and the other end of coil to go via 12 AWG OCC Cu. to XO. No terminals nor speaker posts. Same with tweeter wire. The best terminal is no terminal. Guys pay silly money for good quality posts to do the least damage. Rather spend that money on better XO components, like series cap to tweeter. Use your Duelund from amp to XO, again avoiding connectors if possible.

Point 5: You didn’t know you had one? That electrolytic has to go. The tweeter series cap makes a big difference, so does the resistor. What have you got for replacement?

Hi @lemonhaze, thanks very much for your helpful answers, and sorry fow my late reply. I've ordered some parts, and will report back with the results when I have installed them. 

In the meantime, regarding point 4: it did not occur to me that I could solder the big coil directly to the speaker terminal, especially to the mid-bass driver. Is there any specific reason for not putting it in the external XO box, but nearby the voice coil of the driver? 

In answer to your question, I've got some Jantzen Superior Z-Cap and Kiwame 5W resistors at home to start with (plus Jantzen and Mundorf MOX resistors). Later on, I'd like to try Powertron metal foil resistors as well. 

Since originally, this is a thread about hook-up wires, I'll report back especially on the cables as well. I didn't want to steer away from the topic, but this was the pllace where I could find the most helpful answers to many of my questions. Should I start a new thread?