Recording a Flute

Today, we set up to record a flute using two microphones: A Rode NT1-A and a CAD GXL3000. The reason we chose to use these two microphones is because on their spec sheets they are very similar, but in reality give a very different sound and we wanted to see for ourselves how different they really were.

We set up both microphones (shown below) on their stands, each mounted in a shock mount and with a pop shield between them and the performer. A lot of people make the mistake of thinking that the sound from a flute comes from the open hole at the bottom of the instrument, but this is not the case; the sound comes from the mouthpiece, where the performer blows through when they play. With this in mind, we positioned the microphones opposite the mouthpiece while the pop shields each protected them from any unwanted "pops" in the recording that is caused by the performer blowing into the microphone.

(Ignore the vocal shield and the unused pop shield behind the two microphones, they weren't used in this setup)

After providing our performer with a set of headphones so that we could talk to them whilst in the studio, we began recording. After recording the piece and listening to each microphone separately, we found that the NT1-A was a lot louder than the GXL3000 despite the gain levels being the same. We consulted the spec sheets for the answer to this problem and soon enough, we found it. Even though the sensitivity of the two microphones were almost identical, they had very different "Self-Noise" or "Equivalent Noise Level". This refers to the noise that the microphone itself produces, which it then reduces everything by that value so that it doesn't interfere with whatever is being recorded. Our problem was that the NT1-A, which prides itself as being the world's quietest studio condenser microphone, produces a tiny 5dB of self-noise whilst the GXL3000 produces a much louder 20dB of self-noise, resulting in it being 15dB quieter than the NT1-A.

Recording a Grand Piano

Today we looked at different ways we could mic up and record a grand piano. We were given an article from Sound on Sound magazine which had a few techniques already on it but, after reading it through, decided to try our own technique(s) instead.

To begin, we opened up the lid on the grand piano so that we could see the strings, sound holes, dampers, and hammers. This allowed us to place the microphones closer to the source of the sound, so they could pick up the sound produced by the piano clearer. We used three Rode NT-1A Condenser Microphones for this job, placing one above the higher pitched strings, one above the lower pitched strings, and one about 1 - 2 metres away from the piano to record the overall sound and ambiance of the instrument. Since these microphones are condensers,  they have a high sensitivity and can therefore pick up the sound at a higher level which makes them useful for this particular job.

The NT-1A has a very good frequency response for recording a grand piano (shown to the right). As you can see, the frequency response is fairly level, with a small presence peak between 100Hz and about 500Hz, and also boosts frequencies above 1000Hz slightly more than anything below this level. In general this is a very good frequency response, but it is especially good for recording piano due to the sheer range of frequencies that a piano can produce which make it such a popular and beautiful instrument to listen to - and we want to be able to capture all of those frequencies, and the NT-1A allows us to do just that.


The polar pattern (left) is also a notable feature of this microphone that allows it to record the piano well. Since it is cardioid, this allows it to pick up all frequencies at the exact dB level they are being played at as long as the microphone is facing the source. It also reduces sound from the back of the microphone, helping to eliminate unwanted background noise (depending where the microphone itself is placed, of course).




After setting up the microphones, we moved onto the next hurdle: plugging them in. Usually this isn't a problem, but in this situation our recording space (an empty classroom) was across the corridor from the studio and did not have an input box to plug the microphones into. To overcome this problem, we used a multi-core audio cable (shown in the image below) to run along the floor all the way to the studio, allowing us to plug all of the cables indirectly into the jack field. Next, we placed a small monitor (also shown below) in the room near our performer so that we could talk to them via the talkback button on the mixing desk. The reason we didn't used headphones this time was solely down to our performer's preferences - the headphones would only get in the way of the performance.

After our recording, we decided to try using a D112 Bass microphone to record the lower frequencies from the piano. We set up the dynamic microphone in the same way as the one we have just replaced, and after recording another performance we found that this gave the song a lot more bass to it and made it sound deeper in general, which might be what you want from the recording.

Recording a Guitar

To record a Guitar with a DI Box and a microphone:

Find out where the guitarist will be sitting/standing so you know where to start setting up the microphone. Using your chosen microphone, place the microphone pointing towards the sound hole of the guitar but make sure that the guitarist has enough room to strum and play - otherwise they might end up hitting the microphone! A cardioid microphone is usually best for this job, but that doesn't mean you can't use any others - in fact it's best to experiment to find which one sounds best to you. I usually use a Rode NT-1A Condenser microphone to record guitars, since it has a cardioid polar pattern which records best at the front of the microphone. Since it is a condenser, it has a high sensitivity so it can pick up pretty much everything that the guitar plays.

Next, connect the DI Box to the guitar and into the inputs on the wall. This will pick up the unaltered sound of the guitar, but will not pick up the sound of the strumming or tapping of the guitar which is sometimes desired.

Recording a Bass Guitar

In class, we recently recorded a bass guitar but this time we wanted our bassist to be in the control room with us so it would be easier to talk with him, rather than having to use talk-back and headphones. To do this, we utilised the tie lines on the input box that are in each of the live rooms to use both a DI Box and an amp while our bassist wasn't even in the same room.

We used an AKG D112 Dynamic microphone to record the bass amplifier, and placed it roughly 6 to 8 inches away from the main driver, pointing towards the center. This microphone is usually are go-to microphone when it comes to recording bass sounds, simply because that is what it was made for. The D112 has a very large diaphragm, which allows it to pick up lower frequencies with larger wavelengths better than a smaller microphone. It also has a very good frequency response that boosts bass frequencies between 20Hz and 200Hz.

In addition to the D112 recording the sound of the amp, we used a DI Box to pick up the pure sound of the guitar itself. To do this, we plugged the guitar into the patch bay/jack field in the studio where our bassist was, and used the tie-lines to plug a DI box into the same chain as the amp, so the signal would be recorded by the DI Box as well as coming through the amp for the microphone to record.

Using both the microphone and the DI Box lets us record two different sounding recordings which we can then mix together later on.

Recording a Drum Kit

The Kick Drum

To record a Kick Drum, we placed an AKG D112 Dynamic Microphone inside the drum through the sound hole. We placed the microphone so that it was about and inch away from the skin of the drum where the beater strikes. This allows us to pick up the "clicking" sound of the beater when it hits the drum. The reason we used this microphone is because it has a very large diaphragm which allows it to better pick up sounds with lower frequencies due to their larger wavelengths. The cardioid polar pattern of the D112 also allows it to pick up the "boom" of the drum since it can pick up sound from everywhere except the back.

The Snare

For the Snare drum, we used two separate SM57 Dynamic microphones - one for the top of the drum (the skin) and another for the bottom (the snare). This allowed us to record each sound individually so that we can later mix how much of each sound we want in the mixing process. The SM57 is suitable for this job because it can handle louder sounds with it being dynamic and rugged, and because it has a cardioid polar pattern which will allow it to reduce some of the sound that is spilled over from other parts of the drum kit.

The Toms

For the three Toms, we used a D40 Dynamic microphone for each drum that will be used. After making sure which Toms are going to be used by the drummer, we mounted the D40's on clamps that fasten to the rim of the drum, and we pointed them towards the center of the drum skin. These microphones can withstand much louder sounds than condenser microphones, which makes them perfect for recording the Toms.

Overheads

In addition to recording each different part of the drum kit, we also used two tall, extendable microphone stands to have two AKG C430 Condenser microphones hanging over each half of the drum kit, pointing down. These microphones allow us to record the sound of each side of the drum kit, including the cymbals. The C430s are suitable for this job because they, since they are condensers, have a high sensitivity and can therefore pick up sounds from far away and have no need to be close to the sound source where they are more likely to be damaged.