Stereo recording uses various stereo techniques to produce a recording, like a CD. There are different aspects in technique to consider when preparing to record stereo, like microphone techniques, placement, choice.
Each of these sections of stereo technique has an impact on the resulting audio. Some have more, some less, but they make a difference.
This article is meant to be a basic primer, and will focus attention to the various aspects of it. For an introduction to the idea, such as why we want to record in stereo, see the Stereo Recording Intro.
We will look at:
(If you're new to recording and want to get a better handle on things, check out the recording process page.)
Also, there is another article on choir recording that you should check out if you are interested.
The main difference between any stereo recording technique is whether it focuses on time differences or on volume differences.
If you set two microphones down, one foot apart from each other, any sound that is not coming from directly on center will arrive at one microphone before the other. Our brains can process these minute delays, forming a soundstage, or image of where the sound originated.
Level differences are different - they require directional microphones (where omni-directional mics work well for time difference). The diaphragms are placed together, as close as possible, but pointed in different directions. When a sound comes from off center, it will seem louder from the mic that is pointed in that direction. This is another way that our brains can decode a stereo recording to make the soundstage.
Branching from here, there are ways of combining the techniques to get better sounds yet, and specific instructions on how to implement them. See Stereo Mic Techniques for more the detailed discussion on this.
First, the blend. Any ensemble sounds more blended the further you go away from them. The bigger the group, the further away you need to be before you will have a nice blend of everything. The closer you go, the more you risk hearing individual voices, or losing the cohesive whole sound of the group.
Second, the mix. A recording is made in some sort of acoustical environment, and you need to balance the recording between the sound of the source (be it a choir, orchestra, or other ensemble) and the room reverb.
And don't forget, keep the stereo image centered - don't let the sound become skewed to one side. Your listeners will thank you. 🙂
See Stereo Mic Placement for more discussion on this topic.
It is important to consider what technique you will use, such as time or volume difference (XY, AB, ORTF, etc. - see Mic Techniques ). Your strategy will dictate what mics you have to choose from.
For more on the selection strategy, see Stereo Microphone Selection.
So stereo recording can be a lot of headache, but it is a lot of fun.
OK, now you've picked the perfect stereo recording mic technique, but where should you put the setup? Where the stereo mic setup is placed can make a huge difference in the resulting sound.
Don't believe me? Try it yourself - listen to something up close, and then move away. Move around to the sides and up & down too. Can you hear a difference? As you get further away, the sound becomes more unified, together and cohesive. It sounds more like a group. Up and down also has an impact. Higher up tends to get more back-of-the-group sounds, while lower will pick up the front row the best. Somewhere in between is usually a good point. After a point the further back you go, the less difference it makes.
Side note: get used to listening to how any room sounds. This way, you can be more intuitive in placing any microphone for recording. End note. 🙂
As you move to the sides, the stereo image gets skewed -- you are not in the middle anymore. If it sounds unbalanced at the spot you want to record, it will be an unbalanced recording.
The closer you get to the sound source with your mics, the louder it gets. This seems fairly obvious, but there is another factor in this equation. Every space has a reverb unique to it, and your stereo microphones will record it. But there is a way to control how much gets recorded.
The room sound gets picked up more as you move the microphones away from the sound source. After a point, it will become loud enough to muddy the recording and lessen the clarity (if you have a big room, like a church). In the same respect, the closer the mics are to the source, the less reverb will be heard on the recording.
As you experiment with mic placement and technique, keep in mind that there is no rule that says you can only use one stereo pair. If you have (or can get!) extra mics and recording tracks, try experimenting with two stereo pairs, maybe different stereo techniques (ORTF, AB, Jecklin disk), and in different placements. This will give you more options while recording, and a fuller sound, depending on how the two stereo pairs are mixed.
When you are finding a mic position, keep in mind this good rule of thumb about placement -- the best microphone placement cannot be seen, it must be found. While you might go to a stereo recording and record with the same position you first set up the mics in, make sure that is the best one. You want to make sure you have a good sound before you start recording.
Take your time when you're doing this; it is a critical part of the recording process, stereo recording or not. It can take a long time to get the best recording position, but you want to make sure you get the best sound. Once you find a good place, you've got a lot of work done! Each recording situation is different, so you can use last time's placement to start, but see where the best one is for the current project.
Make sure you like what you are getting. If you don't, you probably won't end up with what you like either. You can do a lot with EQ and processing, but it just isn't the same as getting it right the first time around. Make sure you like the sound of the ensemble or group, the way they blend together, the way they sound as a whole, the timbre, and the mix of the sound source and the room reverb. Get it right the first time, so you won't have to work with junk you wish wasn't there.
Check out some excellent mics for stereo recording over at aZounds.com: the Neumann KM-184 is an excellent mic for working with stereo recording. I have two pairs of them, and love the way they do choirs.
What stereo microphone should you use for a stereo recording? That is an important question in any kind of recording! I hope I don't surprise you, but there is no right answer. There is no rule in recording that says, "When stereo recording choirs of about 24 voices, use a Neumann KM-184."
Every mic has a different sound, a unique character that differentiates it from the rest. Some of them work better on choirs, while another might work better for a drum set. If you have several mic sets to choose from, listen to them all. Make a decision only after that. Even if 3 different mics sound good on a certain application, they each will make it sound different. They will affect what the end sound will be. What do you want that to be?
Apart from questions like that, there are a few guidelines for using choosing a stereo microphone.
A good rule of thumb I use myself when shopping for mics is the old saying, You get what you pay for. An $800 mic will probably outperform a $100 mic. But above all, listen to them.
If you cannot put out enough money for a good mic set without hearing them first, see if you can rent them somewhere. It'll cost a bit, but what's a half-day's rent compared to the cost of a good microphone for stereo recording?
If there's nowhere to rent near you, you could do what I did - I bought two sets of mics to test. I tried them for a day or two, and returned the one I didn't like. Before you do this, make sure you tell your salesperson what you plan to do! The last thing you want is an extra mic set you don't need!
Something to investigate is the possibility of a stereo microphone. Instead of having two separate mics, you have everything integrated into one. Just something to think about.
Just another two analogies about mic selection. Think of each mic as colors on a palette, and you are ready to use each as it suits your purposes. Or think of it like a craftsman chooses special tools to complete a work of art. That's really what mic selection is all about.
Sennheiser headphones make a great asset to any recording studio. As you already know, headphones are an almost necessary part of a bedroom or home recording studio. Of all the kinds available, Sennheiser has a good reputation for quality 'phones.
They have a small selection of studio quality headphones. Sennheiser headphones used to include the HD600, a very nice pair of open-backed headphones. I wish they were still available - you can maybe find them used on eBay. Now, their best studio headphones are the HD280-Pro model.
I've always wanted to try some Sennheisers, so now that my old Audio Technica M40s are seeing some age, I got the HD280 to "augment" their use. Don't get me wrong, I love them both and will use both. But it's good to diversify in sound. You don't want to use the same system for ALL the monitoring, or you will probably miss things.
And the result of my experiment? I LOVE the new headphones. Now I really wish I had some of the old Sennheiser 600s. I will do a review of the AT M40 headphones versus the Sennheiser HD280 headphones soon. But without much critical listening, I think the Sennheiser headphones work better with the low and high end. It has a tendency to over-emphasize the highs, but the rest is fairly smooth. The Audio Technicas lack some on the bass, but emphasize the mids, just a little too much, in my opinion. But they take the Sennheisers in comfort - the HD280 feels very firm, compared to the more relaxed M40.
Sennheiser is a German company, and when it comes to products, whether they are cars, watches, or headphones, German is a good addition to the name! The USA division that distributes Sennheiser products ALSO distributes Neumann - and if you don't know, Neumann is one of the top names in microphones.
All in all, I like my Sennheiser HD280 headphones. They work well for what I need: separation, smooth response, and the coiled cord is a nice touch to keep things from getting messy.
Sennheiser studio headphones = good headphones. 🙂
The above links all go to zZounds.com, a very good place to order audio gear from. However, be a good shopper and check out the price at Amazon too.
What can you use as recording studio furniture, and how should you set it up? This is something that doesn't come to your mind right away when you think about setting up a home recording studio, but in reality it is important. The way the furniture is set up is the way you will interact with your equipment. This can make recording a joy or a pain.
For some of us, it's not that big of an issue. The recording studio furniture is kind of limited by what is in the room that we are working in. When I started, I set up the computer and equipment in my bedroom, on a makeshift desk that also functioned as a dresser.
Not very pretty, is it? But it worked, and I learned a lot about recording in the years since. In other words, you don't need fancy equipment to get started. You can learn about recording without something that looks pretty and sophisticated.
But it sure does make it easier to have a setup that makes things easy to use and work with. My current setup includes a desk I bought at a bargain office supply store, and a rack kit for some audio gear. It still isn't that pretty, but it works great for what I need it to.
The one nice thing that I have that I recommend to others starting in the home recording business is a rack mount. You can see it in the bottom left corner of the last picture. It is simply a box with an open front and back, and rails along the sides to screw in various pieces of audio gear. This holds it in place, and makes for a great way to keep all the stuff together. As an added plus, the connections that go from unit to unit stay put when you move the rack. And it offers a little bit of non-prime desk space, great for other things, like my printer.
You can find a rack kit in several different sizes, ranging from small, being 2 or 4 spaces, to large, with over 20 spaces and casters on the bottom. I like the Raxxess Economy Rack Kit,which is the one I got. For not much money you get a very usable rack. They range from 4 to 14 spaces. The last time I checked, you could get any one of them for just over or under $100.
Another piece of recording studio furniture I saw that might be very useful is a kind of desk. It's called a workstation, and it looks very customizable for different users. It is called the On Stage Total Pro Workstation, and has room for all your recording equipment. There are monitor stands, a spot to put the computer, a desk space, a place for a keyboard, and even a few rack spaces. I would be interested in this if I didn't already have something that works.
In lieu of a big workstation type desk, you can get a simple and quick rack system. On Stage, the same company as makes the workstation, also makes a simple 12 space rack. You can't get much simpler than this - just to L shaped pieces of metal that are connected.
Finally, one last piece of studio furniture that may be handy are monitor stands. In my studio, you see the monitors (studio speakers) are setting on cute little stands at the edge of the desk. The On Stage Workstation includes 2 sets of monitor stands as well. But what if you need a place to set monitors? Consider a pair of monitor stands, which are floor setting stands on which to set monitors and optimize the position so your mixing position gets the best sound. Raxxess has a good set of these. You can fill the center post with bagged sand to add to stability and sound quality.
So recording studio furniture is not difficult, but once you know what's available, it makes it a whole lot easier. Is this all that is available? By no means - there are much more elaborate and expensive setups out there, but for someone looking to start a home recording setup, this list will serve you well. Check out these offerings, and see if they don't give you what you need.
Recording audio books helped me tremendously when I was learning how to record. I don't know if I could have done it without them.
Don't waste a lot of time fiddling with things - get one of these books. You will learn so much faster. It's like having a personal coach by your side.
Reading a book won't give you experience and intuition about how to record, but it will put you in the fast lane to success.
I have several books on recording and digital audio and I'll explain them here and why I like them. Some are helpful in understand how digital audio works, what it does, and what that means to a recording engineer. Others help with practical techniques to use, like where to put the microphone, and helpful suggestions about preamps.
First is Practical Recording Techniques: The step-by-step approach to professional audio recording. This book has a very helpful section on microphone technique for a beginner, and I still reference it. Also, a good discussion of stereo recording. Overall, it's a good introductory book to recording.
Next up is Modern Recording Techniques. This is a more detailed look at things, a maybe bit more technical overall. I like it as a good reference book. Be sure to check it out, maybe after Practical Recording Techniques.
Lastly, Digital Audio. This recording book focuses on digital audio and it's nature, what you need to know about it to record it. (It's out of print, but the Amazon prices are quite good for used ones.)
These are only three books. There are many more! I know these books, and I like them.
Should I consider any other books or resources? Let me know, and if I'll consider it for here.
The study of recording acoustics is a fascinating but intimidating study. However, we'll break it down into several principles that can be applied to help the bedroom recording studio function properly.
Here's the course of action: we split the subject into two topics as it relates to the studio, sound transmission and sound reflection. We'll discuss how they are relevant to the recording studio, and then ways to implement them.
Since I am not a recording acoustics expert and have only worked on one studio (my project studio), I will hand the ins and outs of retrofitting a studio for proper acoustics to people who have more experience. In other words, I'll give you links to research the matter further. 🙂
Very simply, recording acoustics is the study of how sound works - looking at how sound waves bounce or pass through different objects and what amplifies or attenuates (diminishes) them. How does that affect the recording engineer? In several ways.
Everything transmits sound to some degree. Sound is vibrations (something you can feel at lower frequencies), and it is transmitted by transferring the vibrations to surrounding air or materials. When a sound wave encounters an obstacle its energy is split two ways - some of the sound is absorbed and transmitted by and through the object, and the rest is reflected back by the surface. However the denser the obstacle (or wall) is, the less it will transmit, or the more it will absorb.
Our job is to find and place materials in the walls of the studio that will absorb as much sound as possible. There are various materials used, from concrete to drywall, in the walls and floor, as well as different strategies in using them, like building a double wall, hanging two layers of drywall, and filling the wall with insulation.
I prefer to focus on simply recording, which keeps me busy enough. But when I built my project studio I researched somewhat extensively online on the proper principles to use in constructing a studio. I'll include a few that were helpful to me below in section 3. Check them out - they have a lot of good info to absorb.
If you don't believe me, cup your hands to make a tunnel from your mouth to ear, and shout something really loud. As you recover your hearing, let's think about what happens to the sound. It is reflected many times over until it reaches your ear, and it was still quite loud when it got there.
It's that way with a room as well. Whatever you sing or play is reflected off the various walls until it simply loses energy and dies away. Normally this happens with in a second or two, unless it's in a big room (like a cathedral). However for recording we don't want such a large reverb (usually). If it is a big decay time, we have to tame it down somehow.
There are a multitude of ways to achieve this, both cheap and expensive to varying degrees of success. You can put carpet on the floor to absorb the high frequency sound, or put curtains up. This can help some, but most common materials combat high frequency sound, while leaving the low stuff run free. We need some solution to take care of the wide band problem.
Fortunately, some relatively simple options exist. Acoustic foam comes in various shapes and sizes, and even does bass trapping. That is the simplest, most effective way for a small studio/room to get acoustic results.
I can't profess to know all about recording acoustics and solve all the problems. However, others can, and I can point you to them. Stay tuned for part 3.
If you are building your own space or renovating a room, be sure to check out www.acoustics101.com. They have an excellent book on building a room, and what to think about in the structural elements of things. They refer briefly to Auralex foam products for the sound reflections (#2) part of things. I use Auralex products, and am well pleased with them. They offer a wide range of treatment products, from various thicknesses of foam to bass traps and isolation platforms. Check them out at www.auralex.com, or look at some of their products at zZounds.com or at FullCompass.com.
When I was building my project studio I referred to acoustics101.com a lot, and took a lot of ideas from it. Maybe I can describe my studio later, and what all I used in making it.
Another article I found helpful is arts.ucsc.edu/ems/music/tech_background/TE-14/teces_14.html. It has a description of the principles of acoustics, and goes on to talk about practical application of them in an actual room in a house, a bedroom recording studio if you will.
Do you have a link that should be here? Please give it to me, and if it will work for here I'll add it so everyone can benefit.
What can it do for my audio? Audio mixing is one of the most intensive steps in recording.
When you bake a cake, you take the flour, sugar and eggs (whatever they put in!) and mix them all together. This brings about the final product, a finished cake.
When you do this to audio, you take several audio tracks and combine them together into one.
That is the very basic essence of the process, but here are several things you can do:
Levels and panning are two of the most basic tactics used by audio engineers.
The level of a track means how loud it is compared with the other tracks. Normally in digital recording the maximum level is 0 db, which is the top of the ladder.
Most mixers let you set the level up to +6 db. That allows you to gain some extra volume for an individual track, but beware of putting all the tracks up! Here's why...
In digital recording, 0 db is the loudest a signal can go. If it attempts to go above that, it is cut off at 0 db, making a harsh sound known as clipping.
If you adjust all of your tracks up to high, you will probably get clipping, and it doesn't sound nice!
Pan refers to the left-ness or right-ness of a track in a stereo mix.
A stereo track has two channels, left and right. When played by two speakers side by side (or a set of headphones), you can get a stereo image by panning a track all the way left to play out of the left speaker.
When you have a bunch of tracks, you can use panning and levels to make it sound fuller, and also create a soundstage.
That refers to how the tracks are perceived by the listener. A good mix will put the listener into the music, not make him figure out where it's coming from.
Digital effects are one of the coolest things about audio mixing. There are all kinds of different effects to try, like:
EQ is probably the most popular effect available, and the most widely used and abused.
An audio signal is made up of different frequencies. You can classify them as low, medium & high. They can [technically] range from 20Hz to 20kHz. What EQ does is modify certain frequencies so you can make it sound better, or more distorted.
There are two main types of EQ's, graphical and parametric. A graphic EQ has 10, 15 or 30 sliders that boost or cut the sound at a pre-programmed frequency. A parametric lets you have more control, specifying which frequencies and how far around them.
Once you learn how to use them, parametric EQ's can be more powerful and easy to use.
Compression is taking the audio signal, and squashing it down to make it quieter. Then, it is usually boosted back up, but the overall sound seems louder after this. Limiting is close, where it says the sound can't go past a set level, no matter how far you turn it up.
Reverbs are fun to use - they can make a audio track sound like it was recorded in another room. A delay can be used to make an echo, or thicken a track up. Try it sometime!
Pitch effects can change the pitch of your music up or down, from a couple cents to several octaves. It usually sounds goofy, but it is fun to try!
Time effects will lengthen or shorten the track, without changing the pitch. The pitch effect is a little more fun, but this one can be useful at times.
After you have all the levels, panning, and effects you want on each of your tracks you are mixing, you can bounce them down to 1 track, (ie., combine then) There is your final mix!
Most software programs will have a function like this (it might be called something other than bounce). If they don't, you can do it manually...
Set all the outputs of your tracks to internal busses. Then make a track to hold the output, and set the input of it to the output of the others. Then hit record!
Another way to do this is plug a 2-track recorder into your outputs, and record that way.
So now you have your final mix, what are you going to do with it? The next step in the recording process is to send it on to the mastering stage.
What are the differences?
Probably the biggest thing you'll notice is the feel of them. With a hardware box, you have actual knobs and sliders to move with your hands and fingers.
On software, you need to use a mouse to change the settings, or get a seperate control surface. A control surface is something that provides all the knobs and sliders you need to control the software.
If you think that is a little redundant, you are most likely right. But, you get a lot more control over the project with a software mixer.
I personally use a software mixer without a control surface. It would be nice to have one, but I can't justify the cost of it yet!
If you decide to get a hardware unit, but want all the features of a software program, watch out! The price tag gets pretty expensive there!
Software solutions are usually a lot cheaper, when you compare with hardware with the same specs.
This discussion is also covered in a slightly different sense in the digital recording article.
A pop filter is a simple filter that is placed between a singer and the microphone. It's that easy.
But why do you need one? The short answer is that it takes strong plosive sounds from the singer and eliminates or reduces them so the microphone will not hear a giant explosion of sound. The long answer is below.
But first, a look at the filter itself.
Normally a pop filter comes in a round disc-like thing that can be mounted on a mic stand and has a flexible boom to place it exactly where needed. Here's a picture:Plosives are those nasty buggers that come out of the singers mouth and make the mic signal go BOOM. Particularly nasty offenders are 't', 'd', 'p', and 'b'. Practice being a microphone, and put your finger about 3 inches away from your lips. Now start talking, and see if you can feel anything on your finger. Finally, practice just speaking the consonants above.
The material in the middle is one of two materials: mesh/cloth, or metal. In my experience, the cloth or mesh material filters work quite well. To top that off, they are more price economical than a metal one. The metal ones then may be better, but I find that the mesh ones work for what I need them to.
Here is one that I recommend: the On Stage 6" pop filter. It is priced well, and just does the job. The 6" size ensures that the coverage will be appropriate, and it looks nice.
Plosives may be defined as sounds that increase the stream of air coming from your mouth suddenly. When the mic hears it, it feels like an explosion (because of the very small distances). It explodes - hey, that sounds like the word plosive itself, right? Plosive, explode.
The solution is to get the microphone away from the air flow. But that causes problems because the mic needs to be at a specific location relative to the singer to get the desired sound.
Thus, the solution becomes to put something in the path of the air that will direct those plosive blasts elsewhere (or diffuse them), but allow the sound through. This is where the pop filter comes in.
There are many tutorials around on the web about how to make your own equipment, and pop filters are no exception. By all means, check them out. I may even put a how to guide up here someday.
But here's the thing. Whenever I make something like this, the quality is not up to par, and it just doesn't function right. The wire might be bent wrong. The wire might break. It may not stay attached to the mic stand right. It may smell bad. There are a million and one reasons why something I build might come apart. (Unless I put in flooring, because I know how to do that...)
For me, just spending the $20-30 is worth it to make sure I have a functioning unit that looks good. Let's face it, looks are important. Having a professional looking tool makes you feel more professional. It also means you can focus your time and energy on what is important - doing the recording. Prioritize your time and use it wisely.
When I first saw the MOTU 4pre audio interface, I knew that MOTU came up with something good. The 4pre is something I want.
First, some background. I have used two different MOTU interfaces in my home recording career. The 2408 and the 828 have served me well. I love and recommend the 828mk3, which I have and use. The 2408 is nice, but it requires an extra PCI card for a computer, making it less flexible for a smaller recording studio.
I love the options available on the 828, and the quality of everything. It just works. But it only has 2 built in microphone preamps. I wish it had more.The MOTU 4pre has inputs. Four microphone inputs that have preamps built in. This is good. Two of those inputs can double as , and two can double as guitar inputs. If you find down the road that you want more, just get a second 4pre and they will work together.
This is why I like the MOTU 4pre so much. With my current setup, I have to make sure I have a separate mic preamp unit (I have one that has 8 channels, the DigiMax. It works nice, but it is still two separate pieces of equipment. More complexity means more can go wrong. It doesn't mean it will, but it can.
With the 4pre, you plug it in to the computer, and the microphone inputs are ready to go. Aside from things going wrong, this is simple, and that makes it easier to use.
There are two headphone outputs, with separately controlled volumes.
There are four audio outputs. Two are designed for a set of monitors , with volume controlled on the front panel. The other two are for whatever you might need them for. Stage monitors, or a second set of speakers, or whatever.
Digital in and out - it has S/PDIF digital in and out. If you don't know what this means, don't worry. It means that instead of carrying the audio signal in analog form, it goes digital with S/PDIF. Don't worry about it if you don't have any other gear that works with S/PDIF.
The 4pre offers digital mixing. In fact, you can even use it for a live event as the mixer. In other words, an amazing piece of studio recording equipment can also be used for live sound!
Also included with the 4pre is a sweet software package. It includes a number of advanced audio tools, such as clocking, instrument tuning, and an extensive suite of tools for phase analysis. But the real prize is the included AudioDesk software program. I've alread written how I like MOTU's Digital Performer. Well, I really love it. But the great part is that AudioDesk is the little brother to Digital Performer. Most of the functionality and power, and NONE of the price tag! It comes free with the 4pre.
The other great news about AudioDesk is that there is an upgrade path to Digital Performer. Rather than pay full price, you can pay the upgrade fee.
So, from experience, I can say that the MOTU 4pre is going to be a great piece of home audio equipment. 4 channels of high quality audio input and a great software package. It's going to be good.
In short, the MOTU 4pre is well able to be the centerpiece of a small recording studio. Don't wait to revolutionize your recording career!