Intro to Music Production- Assignment #4: Noise In My Home Setup

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acoustical noise, Coursera, electrical noise, home recording, IMPMOOC, Introduction to Music Production, music, noise

This post is submitted for assignment #4 for the Introduction to Music Production course at Coursera.org.

In this post, I will describe the ways I have, with my own setup, encountered acoustical and electrical noise and how I can reduce or eliminate them.

My recording setup is fairly simple, without much sophisticated equipment. I use a Windows laptop to record, using either REAPER or Audacity depending on how complicated the project is. The sound card on the laptop handles sound input poorly, so I use an auxiliary USB sound card (Soundblaster X-Fi) to receive input. The X-Fi has a mini phono jack to receive signals. I run an unbalanced cable (with a male mini phono jack on one end and a male phono jack on the other) to connect an amplifier to the sound card. I connect either a microphone or an instrument (electric guitar or bass guitar) to the amplifier in the input jack. The microphone is a cheap omnidirectional dynamic microphone I got years ago from Radio Shack and badly needs to be upgraded.

I record in an upstairs bedroom that has my equipment but very little furniture. It is a small room, about 18′ long and 12′ wide, with one window. The floor is carpeted but there is a loose floorboard near the door. There is an air conditioning vent in the ceiling. There is a ceiling fan with a light on a dimmer, and two floor lamps that used to have compact fluorescent bulbs until I changed them back to incandescent lights. The room is above my daughters’ bedroom.

I have encountered a number of sources of acoustical noise over time. I have at times picked up the ceiling fan, air blowing from the vents, creaks from the loose floorboard, the sound of the TV on downstairs, my children’s voices downstairs, or my barking dogs.

I use a number of strategies to avoid these acoustical noises. I keep the window closed to avoid outside noise. I keep the fan turned off. I turn off the thermostat to avoid air blowing through the vents. I try not to move around, and I often play seated to avoid the sound of the floor. I try to record when my family is not home or when the children are asleep to avoid them making noise. I will let the dogs out in case they bark. I turn off my cellphone and cordless phones if using a microphone so they won’t be picked up. I keep the door shut to the room. I keep the space I’m working in clear to avoid accidents. I point the amplifier away from the microphone or instrument to avoid feedback.

I have had problems with electrical noises that I have not completely eliminated yet due to equipment limitations. Since my music production is avocational and not professional, I can’t justify making expensive investments in equipment, though I do plan to gradually improve my equipment over time. I have found the fluorescent lights create a lot of noise and had to be replaced by incandescents. The dimmer (and others in the house) must be turned off, because they create noise. (I have experimented with recording by candlelight). There is often a background hum that I have not yet identified, but I believe it is from the cheap microphone; replacing it with a better quality microphone (particularly a directional microphone) will remove some of this noise. Switching to direct input using balanced cables for the guitars will help remove noise from stray radio signals. I may also be picking up a hum from either the laptop itself or from the sound card; I’ll only be able to eliminate that using a noise gate or by using a different recording device. I experienced an alarm-like ringing on a recent recording using my acoustic bass guitar; I have not conclusively found the source of this ringing but I believe it came from the bass amplifier, a Peavey I’ve loved dearly but have used for 25 years, and it is starting to die. I have recently replaced it with a new bass amp but have yet to try it recording. I hope this will help. I am mindful to try and keep the gains down when recording so as not to amplify any electrical or acoustical noises. I may be picking up radio signals from the guitars’ pickups if they are not shielded properly.  I could fix the loose board in the floorboard, but I don’t plan on doing that until I replace the carpet in the room.  (I have considered using a laminate or hardwood floor, which might add an element of natural reverb but might also amplify acoustical room noise).

I have had some success with removing noise using band pass filters and other filters, but have not yet had the opportunity to try using a noise gate filter. I suspect this will be more effective, given that it attenuates all frequencies that are below a certain volume threshold. (This would not have worked for the ringing bell sound mentioned above, because the noise was fairly loud and comparable to the sound of the guitar itself).

It’s been a challenge learning to improve my recordings and minimize acoustic and electrical noise, but it’s been a worthwhile effort, and I look forward to continuing to improve the quality of the home recordings I create.

Sarabande

Tags

Bach, bass guitar, cello suites, Coursera, Introduction to Music Production, music, sarabande

Sarabande from Cello Suite No. 1 by J.S. Bach, performed on acoustic bass guitar.

Recorded by me today for the Introduction to Music Production class at Coursera.

Not meant to be a perfect performance, just a demonstration.  For those of you who don’t know the piece, Yo Yo Ma played it at Ground Zero to mark the tenth anniversary of 9/11.

Here is the text from the accompanying assignment:

For this assignment I completed a recording of my playing the Sarabande from the Cello Suite No. 1 by J.S. Bach on an acoustic bass guitar.  The following is a description of the preproduction, production, and post-production processes involved in making the recording.

This recording can be found at https://soundcloud.com/peculiaritiesandreticence/sarabande-from-suite-for-solo

First, I prepared the room, making sure I had adequate space to work, no distractions, and no stray noise (such as cats or dogs.  The house is empty as my family is not at home.)  I tuned the guitar, warmed up, and spent about 10-15 minutes rehearsing the piece (one I know well but am a bit rusty on, not having played it for a long time). Once I felt ready to play, I connected the guitar’s output jack to my bass amp via an unshielded guitar cable (since I don’t have any unshielded cables and the distance is short).  I placed the amp in front of me, facing away to avoid feedback.  I connected the amp to my computer through the line out jack, with a 1/4″ cable at one end and a phono jack at the other.  The jack connected to an auxiliary USB sound card, which plugged into my laptop.

I started Reaper (the first time I have used it).  I created a new audio track (a mono track, since I was recording input from one instrument), armed the track for recording, then tested levels and EQ, trying a number of variations to get the right sound without feedback, noise, or muddy levels.  Once I was satisfied, I pressed “record” and performed the track.  I did this twice, intending to have enough takes to edit and create a comp recording, then found that the input levels were really too low to be adequate.  I turned up the gain on the guitar and reset levels, then recorded another track.  This time I was satisfied with the levels, but recorded two more tracks, again intending to make a comp recording.  I therefore performed and recorded five separate takes of the Sarabande.

Then I put on my headphones and listened.  I found, to my surprise, that I was quite satisfied with Take 5 and had no need to edit further.  I did find, however, an annoying ringing noise in the recording that seemed to be from the guitar.  It sounded very much like an alarm bell ringing and was quite annoying, even though it was low in volume.  I found using the sonic visualizer that there seemed to be ringing overtones of this bell-like noise at approximately 4000 Hz and 8000 Hz.  I experimented with several techniques to get rid of the bell- low-pass filters, EQ, and others in Reaper, but strangely none of them eliminated the bell sound.  Giving up on this, I added ReaVerb (reverb from one of the stock VST effects in Reaper)- which converted the sound from mono to true stereo- and exported the file to wav format.

From there, I imported the file to Audacity, where a simple band stop filter applied at 4000 Hz virtually eliminated the bell sound (though it was hard to tell now as I was experiencing tinnitus that sounded ike it was at the same frequency!)  I added fade in and fade out.  I had read that bass guitar producers often apply a band pass filter at 250 Hz to eliminate muddy sounds, but after trying it I was not happy with the sound, so I undid the 250 Hz band pass.  I experimented with applying a low pass filter, but doing so took away the brightness of the timbre and the brightness of the higher notes, so I ended up leaving them alone, with a fairly clean recording that sounds much like it did in the room when I played it.

There are several things I would do to make a better recording.  First, I would consider rehearsing the piece for a longer period of time to give a better performance.  As noted above, this piece is comfortable to me but I have not played it in a long time, and it could have been sharper.  Second, I could do more takes so I could have more pieces to edit to create a better recording.  Third, if possible, I would find the source of the 4000 Hz bell noise and eliminate it if possible so it doesn’t get into the recording.  Fourth, if I had the technical capability, I would take input both from the pickup mounted to the guitar body into the amp and from a microphone placed in front of the amp, in order to better capture the sound of the performance in the room. (Unfortunately, this is not possible with my current equipment, as I would need a second computer to record- though I do have a preamp that might be able to be used for the microphone.)

I hope you enjoyed the recording and this description of the process.  Thank you for reviewing this assignment.