Q1: What is there a difference between the different cables —interconnects, speaker cables, and power cables?
Different Cables have different performance :
Cable makes difference, and wrong cable makes wrong result , the difference is obviously to be heard or looked .
In a low-end system, the cable may not cause an obvious big difference ; whereas high end audio system equipment needs good quality cables to reproduce high quality sound which the quipment is made for.
Speaker Cable makes a greater difference than Interconnect Cable ,because Speaker Cable normally has a longer length , it is easy to hear sound's change from different speaker cables.
Interconnect cable also makes a difference as it transmits a precise signal. A good Interconnect cable allows you to hear individually the clarity of each sound and reduce the loss in the sound of signal.
Power Cable is often undervalued , if the cable is supplying a large audio system , the power required to feed it is much greater thus requiring a much-more robust power cable.
About Speaker Cable :
The Right Conductors & Cable Structure are the key designs to enhance power output , balance the bass , mediant or treble and maximize the sound quality .
OFC(Oxygen Free Copper) or TC(Tinned Copper) are the basic and price budget conductors, the most basic and popular items for entry level are 2 cores of 1.5mm2(16AWG),2.5mm2(14AWG)and 4.0mm2(12AWG), these are major used in installation .
Nowadays , some manufactures use CCA(Copper Clad Aluminum) to kill prices , CCA is ok to use for high frequency application , such as CATV cables , but if it is used for speaker cable or power cable , the performance will be very poor.
For the mid to high end level, the conductor size can be much larger (10mm2/7AWG or even larger) depends on the speakers and budget .and expensive materials are often used , such as SPC(Silver Plated Copper, 4 times expensive than OFC) , OCC(6N purity copper, 6 times higher than OFC), Pure Silver(200times higher than OFC) are also utilize.