During my final experimentation session in the studio, I decided to capture a series of vocal recordings. I made use of a wide range of microphones to increase my comprehension of the amount of expression from the singers performance each microphone was able to capture. I also made recordings both with and without a pop shield to help me understand the effect plosive sounds can have on the end outcome of a recording. Additionally I had an opportunity to record in a large, room with lots of natural reverb, giving me the experience to know the effect created by this and what scenarios it may be useful in.

The microphones and techniques I used were:


Microphones:

AKG C214

I used this microphone to make the following recordings:

  • Close Mic’ed (Large Diaphragm Condenser)
  • Pop Shield
  • Echo Chamber (Close Mic)

I decided to use this microphone to capture these recordings for the following reasons:

Frequency Response –  The AKG C214 has a good response overall to frequencies between 250Hz and 16000Hz, the average range of frequencies produced by a female vocalist. As the the vocalist I recorded was female, I used this microphone as it would be able to capture a recording in which the frequencies were balanced.

Frequency Response Graph:

akg-c214

Polar Pattern – The C214 has a cardioid polar pattern which means that it picks up sound mostly from the front. This was useful for recording vocals as it meant that the amount of spill from other sound sources other than the one i wanted to record was minimised.

Sensitivity – This microphone has a sensitivity of 20 mV/Pa (milliVolts per Pascal). This means that this microphone is classified as a high sensitivity microphone. This makes it useful for recording vocals as it meant  could use low gain levels when recording to minimise the amount of spill whilst still being able to capture a strong, clear recording of the vocals.


Rode NT3

I used this microphone to record the following:

  • Close Mic’ed (Small Diaphragm Condenser)
  • Echo Chamber (Room Mic)

I chose to use this microphone for these recordings because of it’s:

Frequency Response – The NT3 has a fairly flat frequency response so is good for capturing a range of frequencies, including frequencies between 250 Hz and 16000Hz, the average range of frequencies of a female vocalist.

Frequency Response Graph:

nt3freqres_clipped-b2482c7da534e729d1d754032bb3a7c6

Polar Pattern – This microphone has a cardioid polar pattern making it useful for recording vocals as it captures audio mainly from the front. This will reduce the amount of spill from other sound sources that is captured and produce a clear recording.

Sensitivity – The Rode NT3 has a sensitivity of 12 mV/Pa, classifying it as a medium-high sensitivity microphone. This made it useful for recording vocals as it meant that I could use a low gain level to minimise spill whilst being able to capture a strong recording of the vocals.


Shure SM58

I used the SM58 to capture the Close Mic’ed (Dynamic) recording.

I decided to use it for the following reasons:

Frequency Response – The Shure SM58 has a generally good, flat response to frequencies within the average vocal range of a female singer (between 250Hz and 16000Hz), however it’s response seemed to trail off when reaching the higher frequencies. However, in order to keep a fairly balanced mix of frequencies through the recording, I decided this microphone would be more suitable than the SM57, which was slightly more responsive to higher frequencies as oppose to the SM58’s flatter response.

Frequency Response Graph:

ShureSM58FreqResponse.jpg

Polar Pattern – The SM58 has a cardioid polar pattern. I found this a contributing factor in my selection of the microphone as it meant that the microphone would mostly capture the vocalist singing into it from the front with a minimal amount of spill from secondary sound sources from other directions, which allowed me to capture a clear recording.

Sensitivity – The SM58 has a sensitivity of 1.88 mV/Pa (milliVolts per Pascal), making it low sensitivity microphone. This was useful for me as it meant that it took a lot of energy to move the microphones diaphragm, minimising the amount of spill from other sound sources that I didn’t want to record and providing me with a clear recording of the vocals.


Other Equipment:

  • Focusrite Scarlett 2i4
  • Microphone Clips/Cradles
  • Microphone Stands
  • Pop Shield
  • XLR Cables

Techniques:


Close Mic’ed (Small Diaphragm Condenser):

The first technique I made a recorded using was a close mic’ed recording using a small diaphragm condenser microphone. For the recording to class as close mic’ed, I had to position the microphone within 30cm of the sound source, which for this session was the singer’s mouth. The microphone I used for this recording was a Rode NT3.

The setup I used for this recording is depicted below.

14858720_940369512734910_743731882_o

See “Vocals – Close Mic – Small Diaphragm Condenser.Mp3” to hear the recording I obtained using this technique.

When listening back to this recording, I found that it had a warm, bright tone. Furthermore, the recording was clear and had a strong signal, capturing the small nuances embedded in the performance.


Close Mic’ed (Large Diaphragm Condenser):

For my second recording of this session, I again opted to use a close mic’ed microphone position, but decided to record using a large diaphragm condenser microphone as oppose to a small diaphragm one. The microphone i used was an AKG C214.

The setup I used to capture this recording is shown below.

14922965_940369492734912_1068674608_o.jpg

See “Vocals – Close Mic – Large Diaphragm Condenser.Mp3” to hear the recording I obtained using this technique.

I found that this microphone captured a very bright recording, brighter and warmer than the recording captured with the small diaphragm condenser microphone. However, similarly to the small diaphragm condenser microphone, the recording had a strong signal and was clear and articulate, capturing the nuances in the vocalist’s performance.

Out of the three different microphones I experimented with, I found this one to be the most favourable as, in my opinion, captured the best sounding recording due to its brightness and warmth alongside its clarity and articulation.


Close Mic’ed (Dynamic):

The third close mic’ed technique i recorded made use of a dynamic microphone as oppose to the two previously used condenser microphones. The positioning remained the same except I used a Shure SM58 instead of the AKG C214 or RODE NT3.

The picture below shows the set up I used to capture the recording.

14894634_940369529401575_1881286563_o.jpg

See “Vocals – Close Mic – Dynamic.Mp3” to hear the recording I obtained using this technique.

Unlike the recordings captured with the condenser microphones, I found that the recording made with the dynamic microphone was more dull and sounded restricted, thin and nasally. However, the recording was still clear and had a strong signal.


Pop Shield:

For the fourth recording I made in this session, I decided to experiment with the effects of a pop shield on the recordings. A pop shield is designed to remove the pop caused by the person being recorded producing plosive sounds, which are a rush of air from the mouth when saying things like ‘P’ or ‘B’ sounds. To carry out this test, I recorded the vocalist from a close mic’ed position using an AKG C214 both with and without a pop shield.

The setup for each recording is shown below.

See “Vocals – Pop Shield Test – Without Pop Shield.Mp3” to hear an excerpt of the recording I obtained using this technique without a pop shield in which the plosive sounds are present.

See “Vocals – Pop Shield Test – With Pop Shield.Mp3” to hear an excerpt of the recording I obtained using this technique with a pop shield in which the plosive sounds are removed.

The difference between the recordings is very clear. The rush of air over the microphone’s diaphragm when the vocalist sings the work “by” causes a ‘pop’ like sound in the first recording where no pop shield was used, However, in the second recording, in which a pop shield was utilised, the ‘pop’ sound isn’t present as the shield reduces the amount of air that rushed over the microphone’s diaphragm considerably to a level where plosive sounds don’t affect the recording. Therefore, through using a pop shield, you increase your chances of capturing a cleaner, clearer rewarding.


Echo Chamber (Dance Studio):

For the final vocal recording I made, i relocated my equipment to the department’s dance studio in the hope to use it to simulate an echo chamber, capturing both the recording along with the natural reverb of the performance within the room.

Reverberation or ‘Reverb’ is the effect by individual reflections of a sound off all the surfaces in a room. The reflections reach the microphone at different, but relatively close time intervals, therefore being perceived as a single sound by the microphone. I hoped to capture the sense of space and depth that the room provided to add liveliness to the recording.

To capture this, I used an AKG C1000 with a pop shield to make a close mic’ed recording and a Rode NT3 as a room mice to capture the reverberated sound.

The set up is shown below.

14894585_940369516068243_1506898283_o.jpg
Close Mic (left) and Room Mic (right)

See “Vocals – Close Mic – Dance Studio.Mp3” to hear an excerpt of the recording I obtained using this technique without a pop shield in which the plosive sounds are present.

See “Vocals – Ambient Mic – Dance Studio.Mp3” to hear an excerpt of the recording I obtained using this technique with a pop shield in which the plosive sounds are removed.

See “Vocals – Dance Studio.MP3” to hear both of these recordings combined.

Post recording, I listened back to each microphone separately and then together. Firstly, i found that the close mic had a bright, warm tone and was exceptionally clear and articulate. The signal was strong and there was a noticeable amount of reverb from the room, though not as much as on the ambient mic.

The ambient mic recording clearly contained more reverb than the close mic, and also had  slight echo effect from sound waves that had undertaken more reflections off surfaces arriving at the microphone at later times than other sound waves that had undergone fewer reflections. The recording was clearly ambient as the distance between the vocalist and microphone could be heard within the recording. Tonally, the recording was warm and bright and had a strong signal and was clear.

When combined, the two recordings sounded lively with lots of reverberation noticeable.

The ambient recording contained a lot of spill from the department as the dance studio wasn’t soundproofed like the recording studio and practice rooms I had used to record other experiments in.


Compression

Compression is an audio effect that is applied to lower the dynamic range of a recording. When listening back to the close mic’ed vocal recording with the AKG C214, I found that there was a large dynamic range within the recording. I decided to use compression to fix this.

To apply the compression, I went to the ‘audio fx’ section of the channel strip in logic and then went to the ‘dynamics’ section of the menu. From there I selected the ‘compressor’. I then adjusted the parameters in the following ways:

I first tried a moderate compression setting, with the threshold set to -10 dB and the compression ratio set to 2. This meant that for every 2 dB going into the compressor, only one came out.

Screen Shot 2017-01-23 at 13.49.26.png

See “Vocals – Compression – Mid Compression” 

I found that this compression setting had very little to no noticeable effect on the recording when it was played back. Consequently I decided to increase the parameters to find out which had a better effect.

I then tried a compression ratio of 4 with a threshold of -20 dB

Screen Shot 2017-01-23 at 13.55.17.png

See “Vocals – Compression – Medium Compression”

I found that these settings suitably reduced the dynamic range of the recording and reduced the risk of clipping whilst  remaining undetectable when being listened to.

Finally, I tried the compressor with high settings with a ratio of 30 and a threshold of -40 dB.

Screen Shot 2017-01-23 at 13.54.52.png

See “Vocals – Compression – Heavy Compression”

I found that these settings made the audio sound as if it was being ‘pulled at’ by the compressor and sounded almost squashed as the dynamic range had been greatly decreased, surpassing what I intended and therefore sounding very quiet.

Overall, I thought that the compressor with moderate settings reduced the dynamic range by the most suitable amount whilst still remaining unnoticeable.

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