Archive for the ‘Noise’ Category

The Sound of Silence

Thursday, August 5th, 2010

As I posted earlier today, I was working on reducing noise levels in my office cum studio. And boy, did I ever.

I wanted to get my computer moved out of the room where I do my recording, but needed a way to actually still use the thing. I ripped an old wall heater out, got a hole saw and punched some holes into cabinets that line the wall on the other side.

From there I put in some ABS pipe bushings- basically I went to the hardware store and grabbed a couple of fittings the right size- to provide a cable run and moved the PC into its own space where the noise it makes won’t be in here.

I’ll just let the results speak for themselves, shall I?

Before moving the PC out:

[audio:|titles=Ambient Noise – Before]

After moving the PC out:

[audio:|titles=Ambient Noise – After]

What did I learn? Well, the PC was a HUGE source of background noise. After removing it, the recording is practically noise-free. There is a tiny bit, but I think that what I’m hearing is from the sound card itself, which is why I’m glad I have an external soundcard on my “to purchase” list. It’s interesting that removing one source of noise reveals another one that was totally hidden before.

With the amount of noise on the recording, I can effectively eliminate noise entirely from my recordings with a minimal amount of processing, resulting in a far higher quality final product.

The main problem with noise in your recordings is that you can use a noise removal tool like the one in Audacity, but it reduces the overall quality and can really only effectively work when you’re not speaking. When you are speaking, the noise will still come through a bit, but is “drowned out”. The lower the noise floor the better your final product will be.

Oh, and pics!

Cable runs from the studio side. I still need to put in a cover.

Cable runs from the studio side. I still need to put in a cover.


The cabinet with a detail of the cable runs.

The other side, showing one of the cable runs and a corner of the PC.

The Beast in its new home

The Beast in its new (and quiet!) home.

Creating a Noise-Free Studio

Thursday, August 5th, 2010

One of the challenges that any person working with audio faces is recording in a noise-free environment. Ambient noise, especially with a really sensitive microphone (like mine), can really have a negative effect on the quality of your final recording.

White Noise

Whether white, pink, brown or rainbow, noise is your enemy

The trick is to do your recording in an environment that is as “sound-dead” as possible. You want two things:

  1. No external noise sources. Any noise coming in from the outside must be dampened or preferably eliminated entirely. I’ve found that even sounds I can’t normally hear come through as clear as crystal when I turn on the monitor headphones. Someone watching TV or chatting in the next room? I can’t normally hear them at all, but when I have my headphones on monitoring the mic, I can hear everything. The best ways to get rid of noise from outside sources? Don’t have any! Turn off the TV, etc. I put a quilt on my door to dampen ambient noise from the rest of the house or outside- like my neighbor, who’s a professional trumpet player (and very good, too!).
  2. No internal noise sources. This one is often a lot trickier, and it’s one that I’m still wrestling with. The problem that many of us who are trying to do quality voice recordings face is that we use computers to do the actual recording; preamps and microphones are silent but a computer is anything but. Computers have fans- usually many of them- and are a major noise source. Even a “quiet” one makes enough noise to make getting a quality recording a major challenge.

In my case, I have a basement room in my home that I’m using as my office and studio. It’s very nearly perfect, as it has cement walls on two sides backed by dirt. One of the other walls faces into the rest of the basement and has a set of cabinets full of both dead space and junk that does a great job absorbing noise. The fourth wall has a closet, once again full of junk and dead space.

The biggest sources of external noise in my studio, in order: 1) The door. Thin lauan doors don’t do a great job of stopping noise. 2) The ceiling. The floor above is not very thick and noise from that direction is a challenge. I combat it by recording when people are asleep or not in the area of the house above me. Since it’s a bedroom, that’s usually not a big problem.

Yes, it has six fans. Actually seven if you include the big one on top.

The biggest source of internal noise in my studio: The computer. It’s a pretty big beast, with a high-end graphics card and a 1600mm(!) fan on top- it’s a little smaller than a dinner plate. Also multiple fans in front and back to keep the drives and graphics cool. Not a quiet machine by any stretch.

(as an aside, the Antec 900 case is great if you want a great case that keeps your system cool)

I’ve had plans for a while to build a sound booth, so I can isolate my recording environment from the computer. That’s still on the agenda, but I realized something that would be 1) a lot easier, 2) a lot faster, and 3) a TON cheaper.

That wall I mentioned that faces onto the rest of the basement with the cabinets on the other side? Well, the cabinets are big enough for a computer. I had considered moving the computer into the cabinet and punching a hole in the wall for cabling, but that seemed excessive and damaging.

I had forgotten that there was already a hole in the wall facing the cabinets. See, when this house was built, an in-wall heater assembly was installed. I shudder to think about what a fire hazard that thing was. See the pics below for what I mean. Since this heater was installed in the wall facing the cabinets, removing it would mean all I’d need to do is cut a very small hole in the back of the cabinet and voila! No computer noise in the studio!

The wall heater was installed in an inset box and removing it would mean shutting off the power to the entire house (or at least the downstairs, which is pretty much 2/3 of the place anyway) while I worked on it. I was trying to figure out when I could do this and not disrupt my family’s life…

When the power failed.

I was working from home and the power goes out for no reason I can figure- nice sunny day, no wind… hm. Call the electric company and they tell me it’s because of “equipment failure”, which I guess means all those Washingtonians who melt in heat above 70 degrees F turned on their AC and blew up a transformer.

So, opportunity knocks! I can’t do any work without the PC, and I wanted to yank the thing, and do that I needed the power off. So I turned off the main breaker as a precaution to the power coming back on before I was done and yanked the deathtrap heater out of the wall.

Heater removed from wall

What I can’t believe is that anyone would install that in a wall. I never used the thing and took the knob off right after we moved in so no one else could either. Just looking at the thing scares me; it’s like looking at a dead animal that you know can’t hurt you any more but still freaks you out.

The wires in the back are the original power and ground wires. They still run to the rest of the room so I had to put (new) wire nuts on them after disconnecting the heater (I know what I’m doing, please don’t do stuff like this if you don’t).

About 10 minutes after I was done, the power came back on! Serendipity, thy name is Puget Sound Energy.

In the back of the hole in the wall you can see a beige panel- that’s the backing panel for the cabinets on the other side of the wall, and about 1/8″ thick. So the next step will be to cut a hole in that and put in a conduit/box of some type that will leave it looking nice.

For the interior, I’m simply going to rip the face off the old heater cover and use that. It’s already got a nice round face that will be perfect for running cables through, with nicely smoothed edges so it won’t cut anything and it fits on the hole already!

So that’s this evening’s project- shouldn’t take more than 20-30 minutes tops and then I’ll have a MUCH quieter studio for recording in. I’m really looking forward to hearing the difference and not having to mutilate my recordings via aggressive noise removal.

I’ll post some sample recordings before and after the changes to give people an idea of how much I eliminated noise-wise.

P.S. Look, people- if you’re going to do any work on your house, office, whatever, that involves working with electrical systems or components, then you damn sure better know what you’re doing or hire someone who does. Don’t take chances!