Hey guys,
A couple weeks ago someone asked a question about the post I wrote about a technique for recording both acoustic guitar and vocals simoultaneously. I figured that instead of writing out an explanation, I would do a video about it. Feel free to watch and enjoy! Let me know if you have any questions whatsoever and I will do my very best to answer it, either in a post, a video or both!.
Peace!
tirsdag 23. februar 2010
søndag 21. februar 2010
Q&A: Any questions?
Hey guys,
So, I have been very busy in studio over the past weeks and haven't had time to write any new posts, mainly because I haven't taken time to come up with a decent topic. So here's what I thought I'd do.
I would like for you to write down any question you find interesting or that you want asnwered in the comment section and I will do my best to answer all the questions I receive. That should keep me busy and you satisfied! xD
Working on some youtube vids as well, so keep an eye out if you want to see Urban Sound Studios and watch me geek on about sound for 10 minutes.
Remember to post those Q's and I'll come up with some A's.
Peace and sonic love,
So, I have been very busy in studio over the past weeks and haven't had time to write any new posts, mainly because I haven't taken time to come up with a decent topic. So here's what I thought I'd do.
I would like for you to write down any question you find interesting or that you want asnwered in the comment section and I will do my best to answer all the questions I receive. That should keep me busy and you satisfied! xD
Working on some youtube vids as well, so keep an eye out if you want to see Urban Sound Studios and watch me geek on about sound for 10 minutes.
Remember to post those Q's and I'll come up with some A's.
Peace and sonic love,
torsdag 28. januar 2010
The Directional Characteristics of Microphones.
In an earlier post I introduced the fundamental recording tool: The microphone. As mentioned in that post, and in a later one about a recording technique microphones have different directional characteristics. Not all microphones pick up sound equally from every direction, or as is most common, from the front.
To understand these differences it is important to understand some of the physics (Yes... everything involves physics) behind the technology. As mentioned in a previous post, sound is the movement of high and low pressure zones in air. These zones and their frequency are called waves. When two waves are added together, say by a microphone membrane into a single electrical current they can reinforce, subdue or cancel each other out entirely.
Keeping this in mind I can go ahead and introduce the four main directional characteristics found in microphones. These are: Cardioid (directional), Omni-Directional, figure-8 (or Bi-Directional) and Super-cardioid.
CARDIOID
The cardioid pattern is by far the most common in modern day microphones. Basically every dynamic microphone has a cardioid pattern. The reason the cardioid pattern works is because of the way the housing around the membrane is constructed. It is formed in such a way that the sound takes longer to reach the rear of the membrane than to reach the front, this goes for sound approaching from the back as well.
When two identical waves hit the membrane at the same time, they will cancel each other out, because the opposing forces will be equal. When the same two waves hit with a delay of half of their period (the time between two "peaks") They will accentuate each other. The delays that the construction of the microphone create means that sounds from the front accentuate each other while sounds from the rear cancel each other out.
The above picture shows a diagram of how a cardioid microphone pics up sound from different directions. Notice that higher frequencies are more directional than low frequencies. This can be very useful in a variety of recording techniques, and is a trait that is shared by all characteristics.
OMNI-directional.
As the name implies, omni directional microphones theoretically accept sound equally from all directions. This is achieved by creating a membrane which is only accessible to sound from one side, meaning that there is no possibility for opposing waves to cancel each other out as with the cardioid pattern.
Interesting results can be gained by using omni mics because they admit a large amount of room sound. They are especially good for larger ensembles such as orchestras and choirs as they do not accentuate a specific person or instrument.
As the above diagram shows, not even the omni-directional microphones are completely omni throughout the frequency spectrum.
FIGURE-8 (Bi-directional)
Figure-8 microphones are directional both to the front and to the rear. This is achieved by haveing one, freely placed membrane. This means that sounds from the front and rear work together, while sounds coming directly from the sides, or the 90-degree axis are completely nulled out. This is the one and only directional pattern which has a 100% null point. This is exceedingly useful in many aspects of recording, and also in calibration of acoustics. When talking into the null, very little of your direct speech is recorded. The only thing recorded is the resulting room noise. Recording uses are numerous (I wrote a post on this topic a few days ago) and can make many tasks much easier.
Again, the diagram clearly demonstrates the way higher frequencies are more directional than lower frequencies.
Many modern microphones use dual membranes and through the use of these can achieve almost infinite variations of these three basic patterns. This is done by summing the signals from the different membranes in different ways, and it is in this fashion that we get the fourth general pattern. This pattern is someplace between cardioid and figure 8 as is called Super, or Hyper (depending on the degree of directionality) Cardioid. This pattern is a lot more directional than cardioid and are most commonly used in broadcast and television applications in the form of Shotgun-Microphones. These microphones use the hyper cardioid pattern whilst incorporating some mechanical modifications to all but eliminate sounds coming from the sides.
As you can see from the diagram above, the influence of a bi-directional membrane is obvious, thinning out the width of the cardioid and introducing a small peak in the rear.
So thats all for tonight. I hope the post has been interesting, both to beginners and those who have been using microphones for a while. Remember, don't hesitate to comment or send me an email if you have any questions.
tirsdag 26. januar 2010
Microphone techniques: Guitar and vocal
If you have ever tried recording a singer who plays acoustic guitar you have probably encountered this problem. Because the guitar is in such proximity to the vocal source, seeing as they are being performed by the same person, there is alot of bleed between the two channels. Getting a good separation between the different sources is often a headache in these situations, where one wishes to process the vocal and the guitar separately.
The technique I am about to write about is extremely useful in these situations, and takes advantage of microphones with a figure of eigh directional pattern (more on this in another post). Different microphones have different directional patterns, meaning they pick up sound differently from different directions. A cardioid pattern is by far the most common and means that the microphone picks up sounds coming streight on much better than sounds coming from the back. Another pattern is the figure of eight pattern. As the name impies, this means that the microphone picks up sounds from the front and back, but rejects sounds from the sides (90 degre axis). Only the figure of eight pattern has a complete nullpoint, meaning a direction where it rejects 100% of all sounds, and this can be used very efficiently for recording an acoustic guitar played by a vocalist.
We start by using two identical microphones (ideally, though it will work with different mics) and place the first one in front of the guitar, and the second one in front of the vocalists mouth. When these microphones are angled so that their 90 degree axis' point directly at the other source they will effectively "null" it out. Now, placement is very important, as the level of separation depends on how accurately you have set up the microphones.
There will allways be some bleed from the guitar or the vocal of course, because we sadly do not live in a theoretically perfect world. The guitar radiates sound over a slight area, and to a larger degree so does the vocal. So there will always be some vocal and some guitar on the respective tracks. The separation however is much easier to work with and better, clearer results can be gained.
The figure of eight pattern is also incredibly useful in other settings as well. Lets imagine a kick drum, if a microphone is placed angling up towards thetoms and cymbals, this will hlp reduce the blled on the microphone, og a hihat mic for example, angled to eliminate the snare or the cymbals.
The possibilities are endles, playa round with them, and have fun!
mandag 14. desember 2009
Recording tools: The Microphone
As with any other process, the tools used are all important, but if I had to decide which tool was the most important (a futile act, seeing as all the components need eachother to function) it would have to be the microphone.
Microphones are the physical "ears" of the recording session. Their purpose is to transate the physical sound waves from the air, into an electrical signal that can then be recorded. Sound is actually the movement of air molecules, or rather the movement of regions of denser and less dense particles. When a 1kHz tone is heard, you eardrum is actually picking up density changes in the air inside the ear, oscillating at 1000 times per second.
A microphone works in a similar fashion. Just as the ear drum vibrates with the air and transfers this energy into nerve impulses, the membrane of a microphone vibrates and translates this energy into electrical impulses.
There are three major types of microphone:
Dynamic microphones are by far the cheapest and most common microphones, especially in project studios and on the stage. These microphones consist of a membrane with a coil of wire attached on one side. In the center of this coil there is a stationary magnet.
Now, when the soundwaves hit the membrane they casue it to vibrate. The vibrations are the same as found in the soundwave. Physics tell us that when a coil of wire moves within a magnetic feild a current in the wire is induced, proportional to the movement. When the membrane moves, the wire moves and a current is induced. now, due to the membrane vibrating in the same way as the soundwaves, the induced current will also be proportional to the soundwaves, with voltage changes representing the wave. Positive voltage peaks are the same as wave peaks, while negative voltages are the same as troughs.
Dynamics are good because they are cheap to make. They are also robust which means you can easily put them in more dangerous places, like a kick drum or the top of a snare drum. One of the problems with them is their relatively low sensitivety, seeing as the membrane and the coil are slightly heavy and therefore heavy to move. This also means that they often have a reduced responce in the high frequency bands. Common dynamic microphones are f.eks. the Shure SM57, SM58 and SM7B. Or the Sennheiser MD421's.
Condenser Microphones use a slightly different princial, though the basics are the same.
A condenser microphone uses a condenser, two plates of metal with a gap between them. A current is passed from one plate to the other, and the gap between them has a resistance, which affects the voltage of the current. When the soundwaves hit one of these plates it vibrates (in the same way as the membrane on the dynamic), thus changing the distance between the plates and therefore changing the resistance. The Resistance changes affect the voltage of the signal proportionally to the vibrations of the membrane.
Condenser microphones require a current to work, and this current is usually provided by the preamp on either the desk or the interface. Most condenser microphones operate on a 48V current. The current is led through the same cable as the sound signal, so on condensers it is not the overall signal which is recorded, but rather the difference in Voltages from 48V. These differences are proportional to the soundwave and can therefore be recorded.
Condenser Microphones are a tad more expensive to manufacture than dynamics. You can however pick one up for around 2000kr (350USD norwegian prices) new at a store that are acceptable. The good thing with condensers is that their membrane is very light. This means they have an extended frequency pickup range and also react faster to changes in volume (transients.) These characteristics make them the microphone of choice for vocals, overheads on drums and acoustic instruments. In professional studios there are often more condenser microphones than there are dynamics, for this very reason.
The last type of microphone are called Ribbon Microphones. These microphones use a strip of very thin metal that vibrates within a magnetic feild. They are not as commonly used as condensers and dynamics due to their high pricetag and vulnerable ribbon. Ribbons also usually have a diminished pickup of the higher frequencies, usually dipping off at 16kHz. They do however excell at giving the source a very warm and mellow, natural sound amking them a good choice for strings, choirs and very often guitar amps. They are often very good on kick drums, but caution has to be made when placing them. Try to angle them at 45 degrees to the membrane of the drum (meaning pointing at the top of the drum with front angled down). This positioning makes sure the pressure from the air rolls off along the length of the ribbon without stretching or braking it.
As allways, leave a comment if you have any questions. I will be writing a post on common microphones, and microphone characteristics soon. Stay tuned!
Microphones are the physical "ears" of the recording session. Their purpose is to transate the physical sound waves from the air, into an electrical signal that can then be recorded. Sound is actually the movement of air molecules, or rather the movement of regions of denser and less dense particles. When a 1kHz tone is heard, you eardrum is actually picking up density changes in the air inside the ear, oscillating at 1000 times per second.
A microphone works in a similar fashion. Just as the ear drum vibrates with the air and transfers this energy into nerve impulses, the membrane of a microphone vibrates and translates this energy into electrical impulses.
There are three major types of microphone:
Dynamic microphones are by far the cheapest and most common microphones, especially in project studios and on the stage. These microphones consist of a membrane with a coil of wire attached on one side. In the center of this coil there is a stationary magnet.
Now, when the soundwaves hit the membrane they casue it to vibrate. The vibrations are the same as found in the soundwave. Physics tell us that when a coil of wire moves within a magnetic feild a current in the wire is induced, proportional to the movement. When the membrane moves, the wire moves and a current is induced. now, due to the membrane vibrating in the same way as the soundwaves, the induced current will also be proportional to the soundwaves, with voltage changes representing the wave. Positive voltage peaks are the same as wave peaks, while negative voltages are the same as troughs.
Dynamics are good because they are cheap to make. They are also robust which means you can easily put them in more dangerous places, like a kick drum or the top of a snare drum. One of the problems with them is their relatively low sensitivety, seeing as the membrane and the coil are slightly heavy and therefore heavy to move. This also means that they often have a reduced responce in the high frequency bands. Common dynamic microphones are f.eks. the Shure SM57, SM58 and SM7B. Or the Sennheiser MD421's.Condenser Microphones use a slightly different princial, though the basics are the same.
A condenser microphone uses a condenser, two plates of metal with a gap between them. A current is passed from one plate to the other, and the gap between them has a resistance, which affects the voltage of the current. When the soundwaves hit one of these plates it vibrates (in the same way as the membrane on the dynamic), thus changing the distance between the plates and therefore changing the resistance. The Resistance changes affect the voltage of the signal proportionally to the vibrations of the membrane.
Condenser microphones require a current to work, and this current is usually provided by the preamp on either the desk or the interface. Most condenser microphones operate on a 48V current. The current is led through the same cable as the sound signal, so on condensers it is not the overall signal which is recorded, but rather the difference in Voltages from 48V. These differences are proportional to the soundwave and can therefore be recorded.Condenser Microphones are a tad more expensive to manufacture than dynamics. You can however pick one up for around 2000kr (350USD norwegian prices) new at a store that are acceptable. The good thing with condensers is that their membrane is very light. This means they have an extended frequency pickup range and also react faster to changes in volume (transients.) These characteristics make them the microphone of choice for vocals, overheads on drums and acoustic instruments. In professional studios there are often more condenser microphones than there are dynamics, for this very reason.
The last type of microphone are called Ribbon Microphones. These microphones use a strip of very thin metal that vibrates within a magnetic feild. They are not as commonly used as condensers and dynamics due to their high pricetag and vulnerable ribbon. Ribbons also usually have a diminished pickup of the higher frequencies, usually dipping off at 16kHz. They do however excell at giving the source a very warm and mellow, natural sound amking them a good choice for strings, choirs and very often guitar amps. They are often very good on kick drums, but caution has to be made when placing them. Try to angle them at 45 degrees to the membrane of the drum (meaning pointing at the top of the drum with front angled down). This positioning makes sure the pressure from the air rolls off along the length of the ribbon without stretching or braking it.
As allways, leave a comment if you have any questions. I will be writing a post on common microphones, and microphone characteristics soon. Stay tuned!
lørdag 5. desember 2009
The importance of monitors
Far too many under estimate the absolute importance of monitoring. Would a specialist in photography use a PC monitor which distorted and changed the color balance of the image? This would lead to decisions being made that would ultimately be different from the ones that would be made in an ideal situation.
The fact is, my friends, that the quality of monitors you use when mixing and indeed recording audio plays a huge part in the final outcome of the track. I know many who think that they can mix effectively with hi-fi speakers. I myself must admit that I was a part of that deluded fraternity. But when I started mixing in a good monitoring environment it was like being able to see for the first time. Details that are unnoticeable on conventilonal speakers became shockingly apparent, and I was forced to rethink alot of my previous work.
The fact is that conventional speakers colour the sound, to make whatever you are listening to as comfortable as possible. Studio monitors aim to do the opposite. In an ideal world a set of studio monitors must have a completely linear frequency curve between 20-20 000Hz because their aim is not to disguise and change the sound to your liking, but to reveal the bitter and eventually unavoidable truth and therefore give you the chance to improve it.
Please, do not do yourselves the injustice of cuting down on monoitor costs. There is nothing that is truly "good enough" and when it comes down to it, save on other aspects of your studio. It doesn not matter how much fancy outboard gear, or how wonderful you microphones and preamps are if you cannot hear enough to make them work. Do not work blindfolded!
Yours truly,
Robin
The fact is, my friends, that the quality of monitors you use when mixing and indeed recording audio plays a huge part in the final outcome of the track. I know many who think that they can mix effectively with hi-fi speakers. I myself must admit that I was a part of that deluded fraternity. But when I started mixing in a good monitoring environment it was like being able to see for the first time. Details that are unnoticeable on conventilonal speakers became shockingly apparent, and I was forced to rethink alot of my previous work.
The fact is that conventional speakers colour the sound, to make whatever you are listening to as comfortable as possible. Studio monitors aim to do the opposite. In an ideal world a set of studio monitors must have a completely linear frequency curve between 20-20 000Hz because their aim is not to disguise and change the sound to your liking, but to reveal the bitter and eventually unavoidable truth and therefore give you the chance to improve it.
Please, do not do yourselves the injustice of cuting down on monoitor costs. There is nothing that is truly "good enough" and when it comes down to it, save on other aspects of your studio. It doesn not matter how much fancy outboard gear, or how wonderful you microphones and preamps are if you cannot hear enough to make them work. Do not work blindfolded!
Yours truly,
Robin
fredag 4. desember 2009
MIxing Tools: Compression
Compression is one of the more vague mixing tools, yet the one that few mixes can use without. A compressor is a dynamic prosessor. This means that it processes the dynamic range of a signal. In music dynamics is defined as the difference between the loudest and the quietest parts of the song. A compressor does what the name suggests, and compresses the dynamic range of a signal.
A compressor is actually an automatic gain rider, doing the job that sound engineers had to do with fader riding in the studio/stage/broadcasting studio so as to have a good overall level without letting the peaks overdrive the tape machine/cirquitry and recently AD converters. A compressor takes on this job by reducing the gain of a signal whenever the signal passes a threshold level. This means that all the dynamics over the threshold are reduced, therefore reducing the dynamics of the overall track, enabling the engineer to have a louder average signal without clipping (overdriving the cirquitry).
Well, thats cool I guess. So how does a compressor work? A compressor is one of the most useful tools in mixing when used correctly, and as all tools, can be destructive if used incorrectly. To the right there is a basic software compressor. The controls are the ratio, threshold, attack and release. The ration determines the rate of gain reduction. On the graphical representation the ration determines the slope of the upper half of the curve. A ratio of 1:1 will rueslt in no change while 1:1000 (or infinity) will result in a horizontal curve. The threshold control determines the level at which the gain reduction kicks in. Graphically the threshold is represented as the "break" in the curve. The attack and release controls are the most important controls to understand, as they determine how fast the compressor reacts and when the gain reduction ceases after the signal goes below the threshold again.
In Use
A compressor is most commonly used to create a balance in a mix without having to automate to much. It can "tighten" up a performance that is uneven because it brings the peaks closer to the "valleys." Getting a controlled vocal track for instance, where there is alot of dynamics, you can pull up the quiter sections without having the loud sections become overpowering.
For percussive instruments a compressor can be very useful. By playing around with the attack and release settings on a compressor you can let the initial attack of the snare (f.eks) pass through, while the gain reduction kicks in and dampens the ring of the drum. This method also works the other way round, by having a short attack time and a short release time the attack of the snare will be attenuated while the ring will be left unaffected. Compressors are good as transient shapers, and if used properly can really help a track become punchy, in your face, or pull it back and move it away from the focus point.
PLay around with them, more info will follow. Meanwhile you can send me a mail to robin.bjerke@gmail.com or post a comment if you have any questions.
Peace
A compressor is actually an automatic gain rider, doing the job that sound engineers had to do with fader riding in the studio/stage/broadcasting studio so as to have a good overall level without letting the peaks overdrive the tape machine/cirquitry and recently AD converters. A compressor takes on this job by reducing the gain of a signal whenever the signal passes a threshold level. This means that all the dynamics over the threshold are reduced, therefore reducing the dynamics of the overall track, enabling the engineer to have a louder average signal without clipping (overdriving the cirquitry).
Well, thats cool I guess. So how does a compressor work? A compressor is one of the most useful tools in mixing when used correctly, and as all tools, can be destructive if used incorrectly. To the right there is a basic software compressor. The controls are the ratio, threshold, attack and release. The ration determines the rate of gain reduction. On the graphical representation the ration determines the slope of the upper half of the curve. A ratio of 1:1 will rueslt in no change while 1:1000 (or infinity) will result in a horizontal curve. The threshold control determines the level at which the gain reduction kicks in. Graphically the threshold is represented as the "break" in the curve. The attack and release controls are the most important controls to understand, as they determine how fast the compressor reacts and when the gain reduction ceases after the signal goes below the threshold again.In Use
A compressor is most commonly used to create a balance in a mix without having to automate to much. It can "tighten" up a performance that is uneven because it brings the peaks closer to the "valleys." Getting a controlled vocal track for instance, where there is alot of dynamics, you can pull up the quiter sections without having the loud sections become overpowering.
For percussive instruments a compressor can be very useful. By playing around with the attack and release settings on a compressor you can let the initial attack of the snare (f.eks) pass through, while the gain reduction kicks in and dampens the ring of the drum. This method also works the other way round, by having a short attack time and a short release time the attack of the snare will be attenuated while the ring will be left unaffected. Compressors are good as transient shapers, and if used properly can really help a track become punchy, in your face, or pull it back and move it away from the focus point.
PLay around with them, more info will follow. Meanwhile you can send me a mail to robin.bjerke@gmail.com or post a comment if you have any questions.
Peace
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