ECN Forum Forums General Topics of the Trade General Discussion Area Wiring a Basement Recording Studio (Part 2)

In my humble oppinion running an isolated ground is what your going to have if you use dedicated circuits. Also when counting conductors you don't include the ground wire (grounding conductor), so 10/2 is a hot, a neutral (grounded conductor) and a ground. 10/3 would be 2 hots a neutral and a ground and using this for 120 volt circuits would be considered a multiwire circuit, and if you lose a neutral you will have 240v and smoke any piece of equipment on that circuit. So if you are truly using 10/3 you might re-consider.

A dedicated IG circuit in a residance is a complete waste of money. You are running NM to a plastic box mounted on a wooden framing member. This makes it an IG circuit already. The only time an IG circuit would be used is if the circuit were ran in a metalic raceway fastened to concrete or structural building steel. Just run a dedicated circuit to get the same benefit.

The best setup for a basement recording studio would be to run a dedicated 240 volt 30 amp circuit to a balanced power transformer with built in distribution. There are several out on the market. Best ones are made by Equi-Tech (http://www.equitech.com/). They will eliminate any ground loop problems on unbalanced audio lines, and have filters built in.

In my opinion I would run dedicated 20 amp circuits using 12-2 nm, don't bother with the 10 its not worth the trouble. Then depending on the actual load, a small UPS(uninteruptable power supply)or series of UPS units ,like for a computer might accomplish some of the filtering you desire, They are out there for upwards of 75 to 500.I found a 1000 va with 75 minute back up for $200. You don't need the battery back up but the power conditioning will be worth the expense.




[This message has been edited by mlk682 (edited 05-08-2003).]

Hey Mike;

What kind of studio are you building, how many rooms? I built a 3 room studio. It's relatively quiet from room to room. I used a noise level meter from radio shack to check actual room variance and from the next room to see how much noise was being filtered out. We built it on a budget, I think I would have done a few things differently now to help reduce even more bleed through noise. Searching on the internet and speaking with people who have built studios gave me plenty of good ideas.

~Ange

Ange,

It is a 2 room studio (control room and live room). They aren't very big but very well designed (I hired a designer but I'm doing the work myself). As far as isolation techniques, lots of double 5/8 drywall on RC channel. I also used lead impregnated vinyl barrier in strategic places. And LOTS of acoustic caulk ($$ . . .enough to pay an electrician to wire it for me : )

I am being swayed to just run the 12/2 NM . . . but it isn't really that much more $$ to do an IG and let's face it, lots of studios have those interesting "orange" plugs that say, "I have special power."

I know if I'm running a dedicated circuit NM to a plastic box then it is IG, but I think I would feel better if I just ran the IG to spec. . . doesn't take anymore work and marginally more money.

Anyway . . . I'm really excited about the studio. The control room will rock . . . diffusors on the back wall, acoustic clouds in the ceiling, cloth lined walls with acoustic baffles in between.

. . . oh and real clean power!

I also just got a sweet A/D coverter. A disconiued model from Panasonic called the WZ-AD96. You can pick up 8 channels for $750 . . . but they are getting hard to find. If you are going digital, I highly recommend it.



Thanks,
Mike

Mike,

As myself and several others have said running 2 equipment ground wires and using IG receptacles would be useless in this application but if you would decide to do this you could not run type NM cable. They do not make any NM cable that has 2 equipment grounds so you would need to run this circuit in EMT, use MC cable that is designed for IG circuits or use HCF AC cable. Your going to be spending alot of extra money just to have a separate ground for the plate screw.

Curt

Point taken Curt . . . the information I've been reading (articles online about IG, home improvement books, I even tried to contact a few folks here off the forum to no success) has not ruled out NM for IG. In fact the Black & Decker book shows pictures of IG recptacles with 12/3 NM.

But I think I will defer to the experience of the members of this forum and run 12/2 NM to plastic boxes.

Question:

There is a segment of the run (from the wall to the studio mix desk) that will be on a concrete floor. I was planning on running that through a small piece of conduit and building a threshold to cover it.

What would an electrician do in this case?

Thanks,
Mike

Hey Mike;

I was surfin the net on what diferences there is between balanced and unbalanced wiring. The balanced has a hot a cold and a ground. You only hook up one end. It shows not to connect to grounded equipment where other equipment is grounded to it through lets say a sheild. I see that the big problem can be what they call a ground loop. Having too many grounds creates an antena. But if you hook them up right, they act as two noisey signals that run at 180 degrees appart so it cancels each others noise out. The extra ground line in a power line, I'm not sure if this would act as a drain, I think it's a good question though. My brother Sparky in VT had recently installed 12/2 M/C armored cable in a hand radio room hoping that this armor would act as a sheild against RFI. This subject gets so deep. I see you went the extra mile on your studio, nice job and good luck.

~Ange