BillFitzmaurice.info

Could someone tell me what the effect of having too thick a cable within the cabs? I'm thinking everything from speaker cable from amp to the wiring in the crossover and connectors to piezo array and main driver.

None. Weight, maybe?
The only loss I can think of would be skin affect...but that occures at too high a freq. For us to care about.

Chris,
My understanding is to use wire that's a balance between an adequate gauge for the distance and power required vs the weight of all the cabling you have to lug around.

Wire is capacitive, inductive and resistive, and in lighter gauge cable this is problematic as it leads to degradation in sound quality over relatively short distances.

Resistance has the greatest influence on SQ, and the heavier the gauge (the smaller the number), the less the resistance.

eg 16G cable should have no significant influence in SQ degredation in runs up to 50 feet/15 metres (with 8 ohm loads), but a 20G wire should only have a maximum length of 6m for an 8 ohm load.

As speaker resistance drops, lower gauge (heavier) wire is needed to prevent degradation to damping factor (a measure of the amplifier's control over the position of the voice coil).

What I discovered while reading not long back, was that many of us take for granted that cable suitable for an 8 ohm load, will also be fine for a 4 or 2 ohm load.
I read a few articles suggesting this isn't the case.

For example, the same 16G cable mentioned above should only have a maximum length of 3.5m when carrying a 2 ohm load.
So, if you wanted to regularly run 2 ohm loads to cabs 15m away from your amp, you should jump to 10G cable.

To answer your question though,
I've already said, there's a weight penalty for heavier than required cable, and it's more expensive as well.
As far as the wire in cabs goes, with proper filters etc, piezo's don't need heavy wire, as they have little current going to them.
Your drivers need something a little more substantial as they are getting more power. If you keep your internal wiring as short as possible, then this reduces any potential problem.

I know that in some plans, Bill has given some satisfactory gauges for wiring the piezo's and drivers in cab. Same again, any heavier than stated costs more and weighs more. One thing, given what I have learned recently, is that if you're running 4 or 2 ohm loads regularly, it may pay to up the gauge, and your parallel loops in cab from speakon to speakon...

You can't have too thick of a cable from the amp to the speaker box. I use only 12 ga on everything regardless of length. It costs a little more, but it's worth it to me to not have to consider where I'm using any particular cable - they are all the same.

The short runs inside the box aren't as critical.....although I still use 12 ga on my subs internally.

On the piezo's don't use a heavy gauge because you run the risk of desoldering the piezo element before you get the solder to flow on those big wires. I now use 22 ga bare wire and simply wrap the wire around the lug then just apply a dab of solder, no more cutting and stripping all those wires. Saves lots of time.