This is a much abused issue with a lot of misconceptions and a lot of money wasted on so called miracle solutions that interconnects and cables can make. Remember better interconnects and cables can not improve any component’s sound, they can only have less influence on the total sound of the system. So if you do not hear any difference in the sound with different interconnects and cables, do not spend more money on them.
Good interconnects are in my view the most important cable in your system. Most systems can benefit by upgrading from the standard leads that come with your equipment. Some experts suggest spending 10% of the system price on interconnects. I would generally look at spending 10% of the source equipment on interconnects. For example, if your CD player cost $1000 then spend around $100 on an interconnect.
In terms of video cabling, most people are opting for HDMI cables, but that doesn’t neccessarily make it the best. When choosing an HDMI cable make sure it is certified to handle a FULL HD 1080p signal. All the HDMI cables that we stock carry 1080p signals over long lengths. For digital sound connections I prefer co-ax instead of HDMI, it has less dither problems because they do not need handshaking with components, Co-ax cables use proven technology and it keeps the video and audio signals completely separate. It is best to keep your cables as short as possible, the longer the cable, the more likely it is to pick up extraneous noise.
On the issue of speaker cables you need to consider how long your cables need to be. Shorter is always better but sometimes this is unavoidable. Don’t be fooled by speaker cables with huge thick shielding, it is this shielding itself that can have negative effects on the sonics of the cable. Another thing to consider is the quality of the cable inside your speakers, it is a waste of money to spend a huge amount of money on thick cables if the cables used inside your speakers are thin cheap wire. Quality speakers use quality cables inside and then it make sense to try and match that quality level. The same argument goes for speaker terminal connections. The simplest and sometimes the best way is to just push the bare wire through the speaker’s binding post hole and tighten it. However, if you choose to bi-wire your speakers, this sometimes isn’t practical. Also, there is no need for special expensive gold plated plugs if your speaker manufacture used cheap zinc clips inside the speaker to connect the connecting posts to the crossover network! However plugs are very convenient for switching between speakers etc. In general twisted speaker cables are the best to reduce induction noise effects. The better quality the speakers the better quality speaker cables can be used.
In terms of bi-wiring, the degree of effectiveness depends on the speakers and their cross over units within them. Some very well regarded manufacturers (such as Dynaudio) do not even provide the ability for bi-wiring. Bi-wiring is something that we recommend enthusiasts to experiment with, but it will be small differences in the sound that you notice, not day and night comparisons. Single wiring is suitable for most applications.
Power Cables & Conditioners:
Roughly the same argument can be used here. There is a new trend to push this issue at huge cost to the clients to achieve miracle improvements. However respectable amplifier manufacturers spend huge amount of money on research in designing their power supplies to be insensitive to noise and problems in the power supply. Only if this goes outside their reasonable stable assumptions, like a huge power spike or drop in the supply then you can have problems. I normally just recommend a good spike and surge protector plug as essential to keep your equipment safe and sound. Ironically, it is the cheap equipment that needs these expensive power conditioners the most and these clients can not afford them!
Finally, my recommendation to all these miracle improvements is to try them first and if you can hear a difference only then consider buying one. If their price is more than an upgrade to a better speaker, rather go for the better speakers, this is still the component that shapes the sound the most!