past paper 1 Flashcards
What is the sample rate and bit depth of a standard Audio CD?
Sample rate = 44.1 kHz
Bit depth = 16 bits per sample
Explain the difference between a compressor and a limiter.
The difference is only in the compression ratio used.
What does a limiter intend to limit?
The maximum level, usually to provide overload protection. This involves setting a threshold close to the maximum desired audio and using a very steep ratio (anything above 10:1).
How does the ratio on a compressor differ to a limiter?
Compressors tend to use lower ratios; typically 5:1 or less. This allows less drastic and more creative dynamic control.
Describe the use of attack and release times on a limiter.
A limiter tends to have much faster attack and release times than compressors, so that it can respond to brief transient peaks very efficiently, and without affecting the rest of the audio signal.
Describe the use of attack on a compressor.
Compressors tend to be set up with a slower attack specifically so that they don’t squash the attack transient on percussive sounds.
Describe the use of release on a compressor.
They usually have a slower release so that their gain changes are more gentle; more like pushing a fader up and down.
When would you use a limiter on vocals?
You won’t want to use a limiter if the vocalist is particularly dynamic. But for a rock or pop song where your vocalist’s volume is going to be staying in the same general area, a limiter can come in handy.
How might a limiter be used for vocals?
To be clear, when limiting a vocal you’re only going to be shaving off 1-2dB. Nothing drastic! But vocal limiting can be very helpful if you really want to keep your vocal dynamics in one set spot (e.g. top 40 banger).
What problems would you expect when recording a lead voice?
Undesirable room acoustics.
Plosives, sibilance
How might you solve the problem of undesirable room acoustics when recording vocals?
Acoustic treatment - head-hight absorptive panels. By placing these in “V” formation with the mic in the middle, you can reduce the influence of undesirable room acoustics. Can also use reflection filters.
How might you solve the problem of plosives when recording vocals?
- Pop filter
- If you place the microphone above the vocalist pointing downward (and out of the direct line of fire) you can sometimes get away without using a screen at all as the air does not hit the diaphragm directly.
- Use a high pass filter on the offending spot.
Explain in detail the effectiveness of a pop filter.
- By creating a barrier between the singer and the mic, pop filters act like a net to ‘catch’ plosives, while allowing other sounds to pass freely.
- The barrier also acts as a distance marker, preventing singers from moving too close.
How might you solve the problem of sibilance when recording vocals?
- De-essers
- Place mic at an off axis angle
- Tie a pencil directly in front of the diaphragm with a rubber band so that the frequency blasts split in half.
Ideal reverberation time: studio control room?
0.3 to 0.5 secs
