Category Archives: Technology

How To Play Like Rubenstein

Last week I was playing Schumann’s Romance in F# major. Frustratingly I just couldn’t get it to sound as gentle as I wanted. Each time I recorded myself and listened back it sounded clumsy. What I wanted to sound like was Artur Rubenstein. Not much to ask, surely!

Well I thought I’d pop Artur on my ipod to inspire me. Beautiful! I’m never going to sound like that! For a bit of fun I thought I’d try and play along.

I was playing on a digital piano. My model can record internally without picking up any room noise. I turned the volume of my piano down, Rubenstein up and recorded what I played.

To my amazement when I played back the recording it was exactly what I wanted. The melody came across strongly and the accompaniment was beautifully light. Perfect! So my fingers can do the job, it’s just my brain that’s the problem.

Newly confident I’m now finding I can play it after all. Ok so still not quite like Rubenstein but I think that would be expecting a bit much!

Reducing Unwanted Noise When Recording

What Is Noise?

In recording terms, noise is an unwanted sound that is captured by our recording equipment. The two main sources of noise in the recording studio are acoustic noise and electrical noise.

The acoustic noise is the noise in the room that isn’t being deliberately produced by the musicians. If you stand silently in a room you will start to notice it. Right now I can hear a humming from my laptop and the TV on standby. I can hear the washing machine from the kitchen and cars on the road outside. These noises are all acoustic noises. They are part of the room I am recording in.

The electrical noise is the noise generated by the recording equipment I am using. Each piece of gear has self noise which is the noise produced just by the gear being switched on. Microphone tech specs often quote the self noise of the microphone. However all the elements of your system will be generating some noise, even the cables.

How to reduce the acoustic noise
Firstly you need to stay very quiet and listen carefully. You will notice all the sources of acoustic noise in your room, as I demonstrated above. For each one you should consider how it can be reduced. Here are some ideas.

  • Move PCs as far away from the microphone as possible
  • Switch off TVs and other electrical equipment at the wall
  • Switch off washing machines or wait until they’ve finished
  • Close the door in the room you are recording in and also the doors to rooms creating noise
  • Place blankets and pillows over the windows to reduce outside noise
  • Use a directional microphone with a cardioid polar pattern. These are most sensitive in one direction so you point them at the source and they will pick up less of the acoustic noise in the room

How to reduce the electrical noise

  • Buy high quality gear that has a lower self noise. Metal is better than plastic
  • Reduce the number of items to the minimum level. Each item adds to the total noise
  • Use short cables as longer cables create more noise
  • Use balanced cables like XLR or TRS which contain an additional wire to cancel noise
  • Place the microphone closer to the sound source to get a louder signal. Each time you increase the gain you introduce more noise so this will reduce the required gain increases

You can reduce noise post production in your DAW but it’s better to get a cleaner signal in the first place by reducing the noise up front.

Understanding Microphones

There are so many different microphones on the market. If you’re setting up a home studio or want something to gig with then you’re going to need some knowledge before you make what could be a costly mistake.

As a vocalist, the two types of microphone that I use regularly are
– a dynamic microphone (Shure SM58)
– a condenser microphone (Samson C01)

All microphones are designed to take sound and convert it into an electrical signal. Devices that change energy from one form to another are called transducers. The different types of microphone convert the sound energy different ways. We don’t need to know the physics behind each type but we do need to know their strengths and weaknesses to be able to make the right decision.

Terminology

Frequency Response
The human ear can hear sounds with frequencies between 20Hz (20 oscillations per second) and 20,000Hz. High frequency sounds are experienced as high notes and low frequencies are low notes. Each microphone has a chart showing its sensitivity at each frequency across the audible range, this is the frequency response. If you want your microphone to reproduce the audio input as closely as possible then you will want a flat frequency response microphone. If you want to use your microphone primarily for vocals then a tailored frequency response would be beneficial. Those designed for vocals will be more sensitive across the frequencies of the voice.

Polar Pattern
Microphones are more sensitive in certain directions. The polar pattern of a microphone shows you these preferred directions.

Phantom Power
Some microphones require additional external power in order to function. We call this phantom power (48V) and it needs to be provided by your mixer or audio interface. Those that do will have a switch where you can turn this power on or off as needed.

My Microphones

Shure SM58 (cardioid dynamic microphone)
This has a cardioid or directional polar pattern. This means that it is most sensitive to sounds directly in front of the microphone, and least sensitive at the back. For this reason it is useful on stage for vocalists as it won’t pick up the monitors or crowd noise in front of the singer and is less likely to cause feedback with the monitors. It also has a frequency response tailored to vocalists. It’s sensitivity is greater across the frequencies created by the voice. I mostly use this microphone on stage for vocals. It’s also pretty durable. You can drop it and it doesn’t seem to mind! Dynamic microphones don’t require phantom power.

Samson C01 (large diaphragm condenser microphone)
This has a hyper-cardioid polar pattern. This is similar to the cardioid pattern for the dynamic microphone. The difference is it doesn’t totally block the sound at the back. It picks it up, although not as strongly as at the front. It’s frequency response is designed to pick up multiple instruments and more accurately reproduces what it hears. It can still be used for vocals, but not on stage as it will pick up the monitors and other room noises and can create a feedback loop. If you do use them on stage to amplify drums then you will need to be careful not to feed the signal through the monitors. I use this microphone in the studio to record vocals and piano. Condenser microphones require phantom power.

Samson C01U (USB condenser microphone)
I have one more microphone that I use regularly which is a condenser microphone that doesn’t require separate phantom power. That is a USB condenser microphone. The model I use is the Samson C01U. It works in the same way as my C01 except instead of plugging into an audio interface or mixer, it plugs straight into your USB port. Levels have to be set on your computer but otherwise it works the same. The advantages of this are there is less noise in your signal because there are less connections and shorter wires. However watch out! Make sure you plug it into a high voltage USB port. I had no idea that the different ports on my laptop provided different powers and was upset my microphone seemed to be so quiet. After experimenting with the different ports I found that one of them works much better and gives me a stronger signal.

Summary

Cardioid Dynamic Microphones
Good for – vocals, stage work, durability, less feedback, no external power needed
Bad for – atmosphere, distant sounds, accuracy

Condenser Microphones
Good for – multiple instruments, studio work, accuracy
Bad for – needing external power, stage work, feedback, fragility

Changing Key with Audacity

I am often asked how to change the key of backing tracks for vocalists.

The simplest way is to purchase the track from one of the providers that allows key changes – such as Karaoke Version.  After you’ve purchased your track you get to alter the key by one or two semitones before you download it.  This site also allow you to download in multiple keys without additional charge.

However, this may not be an option for you.  Or perhaps you need to alter the key by a larger interval.

I use Audacity.  Audacity is a free, open source, cross-platform program for recording and editing sounds.

1 – Download it and install on your pc

2 – Import your backing track (File>Import>Audio). Watch out if you’ve downloaded your track from iTunes as Audacity doesn’t read iTunes files.  In this instance you will need to open iTunes and convert the file to MP3 first.

3 – Select the track and go to Effect>Change Pitch and select how many semitones you want to change it by.  Don’t forget to use minus numbers to change to a lower pitch.  Take a look at the Audacity Help Page for more details.

4 – Export your file (File>Export) and close Audacity (there’s no need to save the project file)

5 – This will create a .wav file which is rather large so I now open in iTunes and convert to MP3 (and delete the .wav file). [Edit – you can download an add-in to enable export as MP3 which is much smaller than .wav – find it here]

Ta-da!!

There are some limitations.  Tracks sometimes sound weird if you transpose by more than 3 semitones. And backing tracks with vocals on can often sound too distorted to use.  This varies on a track by track basis so give it a try.

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