Tips from a Pro: Installing Tielines
My studio inched closer to completion around Thanksgiving when the tieline panels were wired up. Everything went smoothly, thanks to quite a bit of preplanning.
Before the structure was even framed, I consulted with Ann Dentel, a musician and composer who teaches at the Expression College for Digital Arts in Emeryville, CA (see Fig. 1). Ann has 15 years of experience installing wiring in studios, and I asked her early on in the remodel to help me figure out the best way to connect my studio with other parts of the house.
Fig. 1: Ann Dentel prepping a cable before she solders it onto the panel. The red device is for heat-shrinking the tubing.
I took a gamble in picking the rooms where I wanted to direct the tielines. I was betting that the newly raised ceiling in the living room would provide a decent live space when it was done, and that the garage and adjacent storage room would be good echo chambers (or, at the very least, would provide interesting ambient spaces for re-amping). So far, I’m very happy with the way the living room and garage sound with acoustic instruments, so I’ve been chomping at the bit to get the panels installed and start recording.
When I first started talking with Ann, she suggested I install a 1-inch-diameter PVC pipe in the wall between the upstairs studio and each of the three rooms we were linking to below [see Part 5]. She was happy that we had a straight run and that there were no bends or curves (she will explain why in a moment). And by thinking ahead, I was able to keep the pipes at a reasonable distance from the AC lines.
Because the panel in the living room is going to be visible, I didn’t want it to be too conspicuous. So I kept it to 10 channels—eight XLR and two TRS connectors. Same with the garage. I figured I would be using an 8-channel interface for most of the recording I do. (The storage room has a simple 2-channel panel.)
By the time Ann arrived last week, the openings for each PVC pipe were easily accessible and the panels were waiting to be soldered up. In a few hours, everything was wired and ready for installation.
Because many of you will want to do the wiring yourself, I asked Ann to share some tips for installing audio cables between rooms in a house or studio.
What’s the first thing a person should consider when running tielines?
If you’re running cable from one room to another and you’re putting it through a pipe of some kind, you have to make sure the cable can be pulled through the pipe. That means you don’t want squishy, soft jackets around the cable. You want a hard, smooth jacket. You can feel the difference just by holding the cable.
How many cables can you get through a tube that size?
You can easily run a couple of 24-pairs [a snake or bundle containing 24 individual cables], or maybe four 8-pairs. But it depends on the cable, among other things. I don’t think it matters how many you put in there, as long as there’s room for the cables to pull through easily.
Is it easy to maneuver the cable through a pipe that has bends in it?
No, it’s not. Try to have a straight run whenever possible. What you don’t want to do is run pipe that has 90-degree turns in it, because it’s harder to pull the cable through.
What do you do if you can’t avoid having a bend in the pipe?
It’s critical that you use cable that has a smooth, hard jacket, because it’ll pull through easier. If it’s soft, it’ll get stuck, and it’ll tear the jacket. Then you have to pull it out and buy a new cable—not something you want to do.
The best thing to do when you install the pipe is to put a string through it. Tie the end of the cable to it, and then tape it down with electrical tape or gaffers tape so that the string that you’ve tied around the cable doesn’t come off. Then you pull it through.
If you’re pulling three 8-pairs through the pipe, do you use several strings?
Use one string. You just hold them together and do all three at once. There’s a special knot—I don’t know the name of it—that I learned long ago where the harder you pull, the tighter the knot becomes so that the knot doesn’t come loose. You can do the research to find a knot where the tighter you pull, the tighter it gets.
Then you tape, with electrical tape usually, the three cables together in one big bundle that hopefully doesn’t have a blunt end. It should have a sort of pointy end where the string comes out so you can pull it.
Are there specific things to avoid when running cables in a wall, such as running parallel to power lines?
People run audio cable parallel to power cable all the time and get away with it, but it’s kind of a dangerous game. Even though it’s in a separate pipe, you could potentially have a capacitive coupling and get noise induced into your audio from the AC. So if you don’t have to do that, don’t do it. Sometimes you don’t have a choice, but it’s better to avoid it because once your audio cable and AC are in, trying to fix the problem is expensive.
And absolutely do not run the audio cables in the same conduit as the AC.
Fig. 2: Eight XLR jacks wired. Notice the tubing that keeps the wires from shorting against each other. Also visible are the white cable ties used for strain relief, so that no single solder point has pressure on it.
You also have to think ahead and plan the size of panel you’ll need. The more cable you have, the larger the panel, right?
Not only do you have to determine how big the panel is, but how much space you’ll need behind the panel for the wiring to come out of the hole and be able to spread out to connect to the different jacks. You need 2 inches free behind it, for the full size of the panel, so that when the cable gets broken out to different points, there’s room.
Can you recommend any parts or cables that are stellar?
Standard pro-audio cable. Belden and Gepco products are made in the States. They make industrial cable that has the smoother outer jacket that I was talking about, which you can pull through conduit without a problem. Canare and Mogami are both excellent companies, both Japanese, more expensive, but they make really great cable. They don’t have the same hard outer jacket, though, so you have to be a little careful.
In your studio, we ran Mogami and Canare, but we were running one 8-pair (Canare) and one 2-pair (Mogami) in a 1-inch pipe. There was lots of room and it was a straight run.
Don’t buy something you’ve never heard of, in terms of the cable or the connectors. Buy standard, well-known brands. The ones you don’t know about, you don’t know about for a reason. Neutrik and Switchcraft connectors are both quality connectors, for example.
What other suggestions do you have for musicians who want to install audio cable between studios?
Get advice from contractors. If you’re going to put a pipe in a wall, make sure that you know what you’re doing. Don’t just run a conduit through a wall without finding out what’s in the wall. That seems somewhat obvious.
Measure things carefully, especially the length of the cable. Make sure that you don’t cut a cable that’s too short—measure long, keep it long. You can always cut it down. If I measure a 14-foot run, I’ll cut a 17-foot cable. I’ll add 3 feet, total, for a short run. Some people will add more.
It also depends on what you’re doing with it. If it’s just going to a panel that’s right there, that’s plenty of slack. But if you’re talking about going from a pipe over 10 feet in a room to a console, then you want to really be careful. Make sure the cable can reach the console and that you can break it out the length needed to connect it to whatever it’s connecting to. So add 5 or 6 feet.
Can you share any tips on soldering and assembly (assuming that we already know how to solder)?
Obviously, the solder points need to be good solder points, otherwise they will fail. That’s always where stuff fails—at connection points.
And always think about strain relief. You don’t want a situation where there is any strain on the solder points on the connectors, because that’s a failure. It may not happen tomorrow or next week, but it could happen next month.
If it’s an 8-connector panel, I take tie wraps and tie the wires together where they come out from the connectors (see Fig. 2). It’s not really tied to anything, but because the cables are connected together in this way, when you pull on the cable, the strain is dispersed.
You’re pulling on all eight connectors at the same time, instead of just one?
Exactly. So if you unscrew the panel from the wall and pull it out, it’s not going to put strain on any specific solder point. I also put a hook in the wall behind one upstairs panel for strain relief because I was worried about the weight of the cable pulling it down (see Figures 3 and 4).
At the end of our chat, Ann reiterated the importance of consulting with or getting advice from somebody who has done the work before. Among other things, they can show you ways to prep the cables and keep things from shorting against each other so that you don’t have to learn those lessons the hard way.