Recording Vocals
Evidently, different microphones suit different situations.
On this occasion we are recording pop vocals beginning with the SM58.
If the manufacturer's specifications are anything to go by, we should expect a good clarity of presence around the 2-5kHz region.
After initiating a mic sweep we found that the best sound for vocals came from positioning the mic around 0.2m away from the source.
SM58 0.2m from source by firemanfloaf
It would be naïve of us to judge the sound in isolation or without comparison, so let's listen to the same verse but on a Neumann U87 condenser recorded 0.5m away (post audio sweep).
Neumann U87 0.53m from source. by firemanfloaf
(-10db, cardioid polar pattern)
Now it gets interesting. First of all, compared to the U87, the SM58 sound appears to be quite thin and precise. The U87 wins hands down with regards to the lower frequency response as it brings a warm sonorous quality around 100Hz. However, this does not deem the SM58 ineffective.
The graph below represents the comparison in frequency response between the two.
This presence area (2-5kHz) would cut through hard, muffled sounds at a live gig so it is easy to see why many live engineers favour it.
Another perk of the SM58 is its response to background noise. Thanks to its pneumatic shock-mount system, we can barley notice the raucous noise coming from the above recital room. With the U87, it is apparent that there is spill from our noisy environment.
It would appear advantageous to consider using a condenser (in comparison with a dynamic). The U87's impressive linear response will mean that less post EQ will be required.
However, in a live situation, an SM58 has the ability to cut through heavy/dull sounds.
Summary
SM58 – Sharp and Tough
U87 - Clear and Meticulous
Which Cardioid for Vocals?
Regarding the recording of vocals, let's compare the Neumann U87 with the AKG 414, another cardioid.
Using headphone sweep again, we eventually settled on 0.2m as the optimum distance.
AKG 414 - 0.2m - 0.5m by firemanfloaf
Listening to the AKG timbre, it appears quite harsh with our vocals. Like the U87, it handles low frequencies with ease but the AKG is lacking presence. I wouldn’t preclude the possibility that this is a direct result of the close proximity of our mic in relation to the source. However, could the AKG 414 be more suited for speech and instrumental recording?
To be sure, I recoded the same again but this time at 0.5m.
Instantly, the sound we heard was extremely muffled. This shows us how sensitive the AKG 414 is at distances. The U87 is able to handle a similar distance comfortably.
Setting reverberation and acoustics aside, the U87 appears to be the best option with regards to recording male pop vocals. This could all change however depending on the age/weight/style of the singer.
Recording Guitar
Shure SM58
After sweeping we began recording at a distance of 0.2m. The sound from the SM58 appeared to be high in presence, but not so successful around 150Hz. Pointing at the sound hole definitely makes our recording bass heavy. However, when we move it just off centre (towards bridge), we are left with a cleaner timbre.
Neumann U87
The Neumann U87 produces an ‘60s’ sound. It certainly comes across muffled. If we gave the U87 a score of 10 for hardness, the guitar would figure around 5. If we are trying to pair hard mics with soft instruments, maybe the U87 is not the best for guitar.
AKG 414
The AKG 414 is constantly impressive in the instrumental experiments. On guitar it gives the brightest tone of all microphones tested (especially in cardiod and -10db settings). If we were to combine an AKG with an SM58 this might give more body to solo guitar tracks.
Recording Flute/Low Whistle
Low Flute - All Mics by firemanfloaf
Similar to flute, mic placement on a low whistle can be quite tricky due to the excess air omitted from the sound hole. From the mic experiments conducted, it is evident we must keep a safe distance from the sound hole, while at the same time trying not to stray too far from the source so that the quality is not jeopardised. We found that a foam pop guard can help reduce excess air omitted.
SM58
After sweeping, we began recording at a distance of 0.2m. The SM58 produces a clean tone but lacks depth and fullness.
Of all the recordings, this one was so high in presence that it actually hurt our ears, even with when keeping all signal strength constant. However, the sound was clear and detailed, but lacked in richness. At 0.5m, the sound becomes very echoey, with some elements of phase creeping in
U87
The Neumann U87, like the vocal recordings, captures sonority in the lower frequencies and a mellowness in the higher frequencies. It subtly captures the characteristics of the space it is recorded in without interfering too much with the source itself. However, when we change from 0.3m to 1.0m recording distance, it does not cope well at all. It almost sounds like the Low Whistle was recorded in a bathroom.
AKG
After sweeping and trying to find the optimum polar pattern, we eventually settled on a distance of 0.3m.
When we had previously been disappointed with the AKG’s performance with pop vocals, it was hard to know what to expect when it came to wind intruments.
However, the AKG came up trumps, producing a clean, detailed tone with just the right amount of low end to allow for minimal post EQ. Even at a distance of 0.6m it still sounds consistant.
Experimentations – Mid - Side Technique
Patented in 1934 by Alan Blumlein, this method became popular in the early 1950s, mainly thanks to Danish radio engineer, Holger Lauridson.
The Idea:
The aim of this technique is to create atmospheric stereo sound, using two mono microphones.
To begin this experiment:
We placed a mid mic (Rode NT3) pointing directly at our source (pipes). Before positioning our side mic, it was imperative to firstly sweep with our NT3 using a cardiod polar pattern. After the optimum sound was acquired, an AKG 414 was placed at an angle (90º) using a coincidental placement technique.
The AKG was set to a figure of 8 polar pattern to pick up the side environment.
Recording the two tracks was not enough as the phase needed to be flipped to create the stereo effect we were attempting to achieve.
m+s = x
m-s = y
Below I have included a video that I have created to explain the detailed process of flipping the phase in order to ‘activate’ the stereo imagery.
Listening to our example,it appears that we have created an ambient stereo sound using two mono microphones. There is absolutely no need for a matched pair. The sound produced here would, in my opinion, suit a choir or even guitar/drum overheads. It gives an alternative sound that may benefit textured recordings. Rather impressively, there is a certain crispness to the sound that would simply be hard to replicate with a mono microphones.
What may be useful to consider in the future is the inclusion of a ribbon mic as a side. This may bring a different quality to the recordings.
Experimentations-Unorthodox Techniques.
Watching a documentary on rock band Franz Ferdinand inspired me to think outside the box with regard to mic experimentation and exploration.
In the following exerpt, Alex Kapranos (lead singer/guitarist) plays his Fender in a disused hall in Glasgow. Engineer Dan Carey (Kylie Minogue, Hot Chip) curiously swings a suspended dynamic mic back and forward like a pendulum.
The Idea:
To experiment with the Doppler Effect, thus creating a unique and intriguing result.
Does it work?:
In theory it sounds interesting, but the effect didn't quite translate to the final recording.
A dynamic mic was definetly the right mic to use due to the extended cable length, the ability to work without phantom power and the tolerance of backround noise.
However this idea is riddled with problems:
1) There is always going to be tension on the XLR cable because of the material it is made from and the way in which it is suspended. XLR cables are not designed to be tightly swung from ceilings.
2) Phase problems will be intensified due to the room and ever changing distances of the mic.
3) If Carey was aiming for a pitch change it was never going to work as the mic is directly swinging into the amplifier's sound spectrum. In order for the Doppler Effect to happen, sound cannot bounce off the source that perceives the sound.
Perhaps they should have tried the opposite, moving the amp and not the mic.
In keeping with unconventional recording techniques, here is the result of an improvised recording session with an empty 2 litre plastic bottle.
The Idea:
To direct sound energy towards a hole like water flowing down a drain.
The Method:
The bottom of an empty 2 litre water bottle was cut out. An SM58 was then carefully pushed through on a mic stand. The aim was to get it as close to the hole as possible without touching the plastic. The intended result was that this would stop outside noise spilling into the mic, creating an isolated sound.
Results:
Although this is considered a massive failure, like the Carey experiment, we learn more about what definitely doesn't work, as apposed to what does.
If we listen to the recording we can hear that the bottle acts as a filter. In fact, the sound energy is reverberating against the plastic first before it is absorbed by the SM58. Perhaps a different material that can absorb sound better (e.g carpet) would have been more successful.
Bottle Filter - Preferably Deep River Rock by firemanfloaf
Grill Removal of SM58
The excerpt below contains a normal recording of an Accordion using an SM58.
If we remove the grill we are exposed to a different sound all together. From personal experience the sound resembles that of an SM57, sharper and crisper. However, the grill acts as a pop shield, while at the same time protecting the mic from vapour damage.
SM 58 grill on grill off by firemanfloaf
Assistant Engineer : Paul Harrigan
Musicians :Paul Harrigan and Jason Blyth
References:
In Class Notes/Slides
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