dedicated line.....duh!!!!!!!

[InVeNtOr]

i am buying a custom home and up untill now i didn't think about having a dedicated power line to the home media room. now remember the "home media room" means My living room....lol. i didn't even come up with idea myself, the tech guy at furman sound suggested it to me. my question is besides having a dedicated 10awg line and 20a breaker for the one plug behind my et center , is there anything else i need to do that goes along with that? just to add, i also had that wall (tv, main, sub wall) insulated with celious paper. don't ask me how to spell it, it's the insulation they put in my exterior walls. i figured it would help with the sound reflection and also help out my daughter when she sleeps.

any quick suggestions before i loose that option would greatly apprecieated!

thanks again!

[michael hurd]

If you have a shared wall with a bedroom... IMO the best thing to do to keep sound transmission down is to use a staggered stud wall, 2x4" studs on a 2x6" plate, with the studs on 24" centers. If you can afford it, also you should double up on the drywall on the ceiling, as low frequencies will be transmitted through there as well.

Roxul ( rockwool ) or Fiber-X would be my choice for insulation.... as they are dense and have good acoustical properties.

I would want to plan ahead for the future... are you sure a single 20 amp line is going to be enough current? If you decide to add a large pro amp you would be at the limits already. You may also want to run a telephone line and RG-6 to that area as well... so if you move to a satellite system in the future, you are already set.

[Guest " "]

Dedicated lines that run off the same step down transformer are dedicated only in the sense they have a dedicated circut breaker.

For more info about true isolation, take a look at the equtech website.

[InVeNtOr]

i can't change studs, but they are 16" on center. i also can't change the insulation. what i may be able to do i buy "quiet rock" and have them install it on both sides of the wall, on top of their sheet rock. the wall i share is to my daughters play room. the room next to that is the guest room, and then my daughters room in accross that room. if you look at ryland.com it is the greenwood floor plan. in that same location is all my telephone, sat, network lines. i don't know what all is there but it's called the "verizon package".

well what do i add to that peticular outlet? it is only going to be 2 plug ins, like any standard outlet. how many amps should i have there? i will have a furman elite 15 pfi pluged into one of those outlest and then everything will plug into the furman. so i will have 1 outlet in the wall left unused.

[PrestonTom]

I think by "dedicated line" you mean an outlet on its "own" circuit breaker. Not a bad idea and now is the time to do it. Personally I would not go crazy over power conditioning and isolation. A living room is not a recording studio. You would be surprised what the noise floor in the home is (the electrical line is certainly NOT the limiting factor). Also, grounding problems (hum) does not require an electrician to fix with fancy equipment (contrary to popular opinion). If the wiring is installed correctly, then grounding problems are usually solved by carefully and knowlegibly connecting of the equipment (Furman will of course contradict me on this, but I am not trying to sell anything.....)

One overlooked area is whether light dimmers are being installed. These can sometimes lead to noise in the system (usually with the cheaper versions). Keep that in mind when you speak with the electrician (he will know what you are talking about)

I wholeheartedly agree with M. Hurd's suggestion about dealing with sound transmission issues now rather then later. Please keep in mind that sound is like water and it will find any path to go to the next room (doors, conduit, HVAC etc). This is especially true of low frequencies, which can require heroic measures to attenuate. BTW, going to the trouble of doubling up on drywall or using a sound blocking material, is not fully effective unless you go the entire distance (staggered studs, treating the duct work, doors etc). The analogy of sound and water is an apt one.

Certainly go and search the threads about burying speaker cabling in the walls (the electrician and inspector will have some comments about (fire) codes when this comes up (BTW: I do not mean "fancy" speaker wire).

Good Luck,

-Tom

[artto]

A separate 20 amp circuit should be fine. Even wih higher power amplifiers it's unlikly the peak current will trip the circuit breaker ~ especially with Klipsch ~ less efficient speakers are another matter. In the old days we had things like reel to reel tape decks with three motors each and whatnot, so there was much more current required at times.

What you really want to do is put that dedicated circuit (or two, if needed) on it's own isolated ground. Ground only the power supply, or control center, or whatever it is that your going to plug all this into. The system should be grounded at only one point. Don't directly ground the rest of the components. Let the ground "float" among them and seek it's own level. Use a 3 to 2 prong adaptor on all the remaining components if necessary. This will avoid ground loops which are the source of most noisy grounds.

Forget the extra insulation if you're concerned about blocking sound (sound transmission). Absorption is one thing. Sound transmission is a different problem. In order to block the sound you need to literally block it with lots of mass, or isolate the room//wall/structure. What Mike Hurd suggested (staggered studs) is the minimum starting point for this. If your new "custom" home is being built by a large tract home builder/developer like Ryland you'll most likely find that they are not up to the task of making these kinds of changes.

Many light dimmers will emit RFI (radio frequency interference). Make sure the ones you choose are certified against RFI. RFI is "air bourne" so to speak, so simply putting the lights on a separate circuit may not eliminate it. Also, avoid low-voltage lighting systems as they tend to generate mechanical noise (transformer hum).

[InVeNtOr]

artto, you are right, ryland won't stagger my studs. not hitting
them too hard, but they don't want to do ANYTHING that is not already
on the plans. on the flip side, if you can afford a custom home and
want to make all kinds of changes, go with david weekley. they are the
best at that. i swear it is night and day when it comes to changes.
okay enough chearleading.....

so have the electrican make that
outlet it's own ground. i won't be installing any dimmers. someone
already told me about the problems with them. they said the "chop" the
sign wave and it's just a bad idea to have them. now since i will have
a dedicated line, will the dimmer even effect that HT plug? here is a
pic of the floor plan. i made sure that the insulation went all the
way from the exterior wall into the closet.

now i wasn't sure about the wording in the post, but was it a good idea to add the extra sheet rock or not?

greenwood.pdf

[bhenry]

As long as your lighting and power are on different circuits (which they will be if you run a seperate circuit for your A/V equipment), you'll be fine.

FYI: You don't need 10ga wire for a 20 amp circuit- just #12. The #10 wire is difficult to work with, won't fit properly under the screws on a 15 or 20 amp rated duplex receptacle and more expensive than #12. It's overkill. Also, you may want to consider having your electrician use a 2, or even a 3 gang box for the receptacles for your A/V equipment. Then you could put 2 or 3 receptacles (four or six places to plug in) in at that location.

[Tom Adams]

bhenry beat me to it. Generally speaking it goes like this:

14-2 romex wiring => 15 or 20amp circuits

12-2 romex wiring => 20amp circuits (30amp if dedicated circuit)

10-2 romex wiring => 30amp (or greater) circuits and for 220V circuits

And I agree with bhenry about working with 10-2. I pulled two runs of that stuff in my garage/workshop for a 220V air compressor and OMG.....that stuff was a PITA to pass through studs. And with the cost of copper being what it is....ho - boy!

Tom

[InVeNtOr]

adding this dedicated line, can only an electrician do the work? i mean, i can install a breaker and run a wire in my attic and even hook the wires up right, but does this type of thing have to be "signed off" by an electrican for insurance purposes, or something like that? this is my first home, so i don't know a lot of this little stuff.

i am trying to save money, but if i melt my gear, it's not worth it.

[Duke Spinner]

:

14-2 romex wiring => 15 or 20amp circuits Residential .. 15 amp only

12-2 romex wiring => 20amp circuits (30amp if dedicated circuit) Residential ... 20 amp only

10-2 romex wiring => 30amp (or greater) circuits

[bhenry]

Leagally, the homeowner can pull his own permits and do his own electrical work. If this home is still under construction I doubt very much that the builder will allow you to do this type of work.

Next time your at Home Depot, pick up an "Ugly's" book. It is quite handy. I don't encourage anyone to do this work themselves, but if you must I'll help you as much as I can.

I understand the "saving money" thing (especially with gas at $4.00 a gallon), but shouldn't safety be your main concern? Melting your gear is one thing- melting yourself, your house and or your family is something else. I would reccomend using a licensed and insured electrician (and varify their licenses!!) to do this work for you.

Oh, crap!! The Red Wings just lost in triple OT. Bummer.

[Klipschfoot]

A dedicated line will not isolate interference from other sources in your home. I have a dedicated circuit for three outlets for my audio equipment. I obviously did not do my homework. For example, have you ever lived in an apartment where your niighbor is running something electronic and you see the interference on your tv? I don't know if that is the best example, but you need to clean up the power from the wall. Some products convert AC to DC to AC. That is best done with something like products from PS Audio. Expensive, yes. Maybe some of the Monster line will help as well. Take a look at this: http://www.hometheaterhifi.com/volume_9_3/exact-power-ep15-7-2002.html for something interesting. I don't use one of these - I can't afford one.

Secondly, when I refinished my basement and was at the bare drywall stage (double thickness - TWO sheets of drywall, by the way), it was the deadest room I had ever heard. Then [] I painted. Aesthetics aside, I wish I could have left the drywall unpainted. The hard, nonporous painted surface was the downfall from studio-like sound. Now the wife would have never gone for bare sheetrock but someday...

[LarryC]

I agree with the handiness of 2 or 3 receptacles (4 to 6 places to plug things in) instead of just one. You can never tell when you want another one or two. I did the whole isolated ground bit, plus using "metal-clad" (MC) conduit, although I could tell little difference from the supposed increase in RFI/EMI shielding.

Whether you have one circuit or two depends on how much total current your system uses. Klipschfoot, I assume your SS amp doesn't use much power, but my tube Class A monoblocs are a different story -- 500 watts per. So, for power headroom, I have two dedicated 20-amp circuits -- one for the amps in my living room, and the other to the rest of the electronics in the next room.

I like the PS audio AC-DC-AC P-300 for its improved sonics from motor-driven components.

[tigerwoodKhorns]

If you go through the effort do not put in less than at least three dedicated circuits. This may be a shocker but you may find yourself using a different brand of speaker some day. I use 800 wpc monoblocks. I never thought that I would need this much power but I don't have horns. You will want one outlet for each amp, one for the other equipment and maybe another for a subwoofer. You can run it all off of one circuit (I do right now) but I'd like to have several.

If you go HT you will have many monoblocks and other equipment.

I have a friend who put in one line and he always says that he wishes that he put in several.

[twistedcrankcammer]

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

[InVeNtOr]

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).

[tigerwoodKhorns]

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

[artto]

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.

[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.