InVeNtOR,

Obviously at this point with ksf 10.5 mains and ksw 12 sub, you wont be needing a whole lot of current. I don't know how old you are, or your financial status/potential future earnings, but considder and descide what your possible future upgrades will be. Are you going to grow old and die in this house, or is just a step along the way?? What will your sallary and audio addiction allow for future upgrades along the way. When considdering future upgrades, take in to account that voltage times amperage = wattage. with a mean average of 115 volts at the source times a 20 amp breaker, that gives us a circuit that will feed 2,300 watts maximum. Check the wattage draw of all your components and add them up. If somewhere down the road, you descide you need a 7 channel surround amp pushing 300 watts RMS, that is 2,100 watts of output, but electronics are not 100% efficient (intake is always > output) and the line would also need to be able to recharge the capacitors for peak output, so you would need a single 30 amp breaker and #10 AWG copper just to feed this one piece of equipement. A further thing to take into account is that while some home built sub guys are using 1000 watt RMS amps, they are often in the A/B design, which means lower peak wattage above the base 1000 watt output. Currently the best amplifier souce for subs is class "D", as this type of amp is capable of much higher peak wattage / more headroom for big hits of instantanious bass. I have a pair of Velodyne HGS-18IIs which are by no means top of the heap for subs anymore, but their class "D" amps put out 1,250 watts RMS each, and are capable of putting out 3,000 watt peaks each, so I have a seperate 30 amp breaker and #10-2 AWG copper lines to each of these units. I also built boxes with 30 amp relays for both of these units so that they shut off and are isolated any time the system is turned off, and my input cables are isolated to help prevent lightning strike issues.

                                                           Roger

 i would have no idea what the future holds, trying to buy all the ht in one swoop is giving me headaces as it is.  the one thing i did think about what the furman 15pfi to help with what was mentioned about caps having to recharge.  that device will keep those caps at peak charge.  the sub for the ht will be on a seperate circuit from the ht because it's going to be on my back wall.  (not sure what else runs with it).  the "closet" et center will have everything else.  as far as speakers go, i believe i am going to get some rf-5, rc-7, rs-42 (maybe see if rs-52's fit), rb-5's (or maybe rb-35).  the speakers i have chosen are almost too much for my room now so i am at the peak there.  the electronics will be onkyo 805, acurus 200x3, blu-ray, and maybe ps3 some time down the road.  i refuse to pay that much for video games.  i really don't know what else i could buy that would enhance my ht experience, as far as electronics go.  i am not a 2ch guy, as of now, who knows in 20 years i may be. 

i will how ever give it a thought of adding in 3 total lines (6 total plugs) with 20a circuit breakers, for the just because reason.  if everything works out the way i think it will i will only need 1 plug in that closet (everything plugs into the furman). 

 

Good choice.  Extra lines are extremely easy to add rigth now and very hard to add later. 

The only real way I know of to get what I think you're looking for is to use a balanced isolated regulated power supply, like the Topaz Line2 that I use. These are somewhat large & extremely heavy. They can be bought used on auction generally between $350-$1200 depending on condition. These Topaz units do not use capacitors or transformer switching to regulate the power supply. It truely isolates the output power from the input and reduces line noise and ground loop problems in much the same way balanced XLR cables do. It's simple and efffective but expensive because of the large transformers ~ lots of iron and copper.

  Roger makes some interesting points and seems to have thought a whole bunch about this, however he is most certainly going way above and beyond what is needed for this equipment. His formula for ohms law is correct, but his application of it and installation is WAY overkill.

  His sub may be able to put out 3000 watts in SHORT bursts which any 14 gauge wire would be able to withsand, if this were CONTINUOUS then you would need to upsize the conductor accordingly.

  If you think of it as an electric motor there is a sudden, short amperage draw upon start-up and then the motor settles in and runs at its rated amperage. You therefore have to use a larger circuit breaker to allow for this without having nusiance tripping of the breaker, (there are calculations for this in the NEC) but you would size the wire for the amperage rating of the motor. I have installed #12 THHN wire on 60 amp breakers because of this. If you had to size the wire in this application to the 60 amp breaker, you would significantly increase the cost of the job needlessly. Wire, probably conduit to accomodate the larger conductors and so on would price you out of a job. Plus, fitting #6 wire into the box on the motor would be impossible.

  Not to mention his 30 amp breaker and #10 wire would have to be terminated at a 15 or 20 amp receptacle to allow the sub to be plugged in (unless it does have a 30 amp cord end on it?) which just doesn't make sense.

  My point is most peoples home A/V equipment can be plugged into any standard receptacle/circuit and work perfectly. Do I have a seperate 20 amp circuit for my equipment? Yes. Did it NEED it? Probably not.

  But then again, it's debates/discussions like this that make this hobby what it is.

 

 One other thing you might want to wire in...

If you are are putting in a wired network in the house...definitely run a network connection to the HT gear location. Even better...run it in conduit back to the network center so that if things like in home fiber become a reality in the future, you can re-pull. More and more gear is going to use network access. If you are doing a multi-room audio sytem (at the minimum, prewire for it), make sure you run source lines to the equipment location...again, conduit is even better.  

bhenry:

  Roger makes some interesting points and seems to have thought a whole bunch about this, however he is most certainly going way above and beyond what is needed for this equipment. His formula for ohms law is correct, but his application of it and installation is WAY overkill.

  His sub may be able to put out 3000 watts in SHORT bursts which any 14 gauge wire would be able to withsand, if this were CONTINUOUS then you would need to upsize the conductor accordingly.

  If you think of it as an electric motor there is a sudden, short amperage draw upon start-up and then the motor settles in and runs at its rated amperage. You therefore have to use a larger circuit breaker to allow for this without having nusiance tripping of the breaker, (there are calculations for this in the NEC) but you would size the wire for the amperage rating of the motor. I have installed #12 THHN wire on 60 amp breakers because of this. If you had to size the wire in this application to the 60 amp breaker, you would significantly increase the cost of the job needlessly. Wire, probably conduit to accomodate the larger conductors and so on would price you out of a job. Plus, fitting #6 wire into the box on the motor would be impossible.

  Not to mention his 30 amp breaker and #10 wire would have to be terminated at a 15 or 20 amp receptacle to allow the sub to be plugged in (unless it does have a 30 amp cord end on it?) which just doesn't make sense.

  My point is most peoples home A/V equipment can be plugged into any standard receptacle/circuit and work perfectly. Do I have a seperate 20 amp circuit for my equipment? Yes. Did it NEED it? Probably not.

  But then again, it's debates/discussions like this that make this hobby what it is.

 

bhenry, I did not use regular house recepticles, although 25 amp recepticles most certainly do exist. I did not want the wife or anyone else for that matter to be able to plug into my dedicated circuits. At 1,250 watts RMS a 15 amp braker with #14 gauge wire would be marginal at best. Cost of #6 wire cost prohibitive??? For yo-yos who would spend $1,000 or more on a line conditioner, speaker wire or high priced inter connects, good feed is a much better investment. Why would someone buy great speakers and a high end amp plus all the other stuff and sink $20,000 plus and not build a dedicated listening room when next to speakers, accoustics have the biggest effect?? This relates to power supply as well!!! Why put all the money$$$ into connects etc., and a line conditioner and not pay for a second line transformer and or only be marginal on feed. Very backwards perspective in lack of thought process from my viewpoint!!! Roger