Tuesday, May 12, 2009

How Portable Audio Studios Work

Just a couple of decades ago, if a band wanted to record an album, it only had a few options. Some artists would rent time in a professional recording studio filled with expensive equipment. Others would invest in personal recording studios, either building new structures or converting existing ones into studio space. Building a personal studio can be very expensive, and the space has to be large enough to hold all the equipment needed to produce high quality recordings.



Today, computers and advanced technology make creating a personal recording studio more accessible and affordable. And unlike the large recording studios of the past, you can take these on the road with you. Some bands, like They Might Be Giants, record many of their live performances and make them available to purchase later. The recording studio has gone portable.


Not only can musicians and audio engineers carry around their own recording studios, they can more easily afford their own equipment. A professional recording studio might cost tens of thousands of dollars to construct and bring online. A portable studio can cost a fraction of that. Still, you get what you pay for. If a band chooses to skimp on certain equipment, it might find that the recordings it produces aren't of the best quality.




The components of a port­able studio are very similar to a traditional recording studio's equipment. But a portable studio tends to assign multiple production tasks to a single device so that only a few pieces of equipment handle the same duties as a studio full of gear. And just because a studio is portable doesn't mean you can pop it into your pocket. Depending on the components involved, a portable studio might require an audio engineer a few trips back to the van to carry it all inside.

Portable Audio Studio Hardware

The most important piece of equipment in any portable studio is the digital audio workstation (DAW), also known as a computer. Depending on the software on the computer, a DAW could act as a recording device, mixer and sequencer. By handling so many tasks, a good DAW reduces the need for additional equipment.

Handling audio files requires a lot of computer horsepower, particularly if you're mixing lots of channels. For that reason, it's important to choose a computer with a fast microprocessor. For a while, it seemed like Mac computers would always reign supreme in the world of media computing. But some audio engineers say that the differences between Mac and PC performance are negligible. As long as the computer you pick has a powerful CPU and a large, fast hard drive, you're in good shape.

Another piece of the portable studio setup is the audio interface. While many computers have input and output ports and sound cards, they aren't always capable of recording or playing back professional-quality sound. For that reason, many engineers who set up portable studios rely on additional audio interface devices. These devices range in size from a handheld gadget to a machine the size of a hefty VCR.


Audio interface devices usually have multiple input and output ports. Many have both analog and digital ports, which covers all musical instruments and microphones. Some also act as analog-to-digital converters (ADCs). That means the device can accept an analog signal and then digitize it. It converts sound into information that a computer can manipulate.




Analog signals are continuous waves that vary in frequency and amplitude. An analog audio signal's frequency corresponds to the sound's pitch. The wave's amplitude represents the sound's volume. Digital signals aren't continuous. Instead, a digital signal is a series of snapshots called samples. The number of times a computer takes a snapshot of an analog signal per second is the sampling rate. Higher sampling rates translate into smoother, more natural sound.



Not all audio interfaces are also ADCs. Some audio engineers might prefer to use a dedicated ADC, then run the signal coming from the ADC through the audio interface and into the DAW. Either way, the audio interface carries the signal to the DAW. Audio engineers use the DAW to manipulate individual channels and mix the sound into a final track.

Portable Audio Studio Software

Even a powerful DAW is useless without the right software. There are several music studio software packages on the market. Some provide audio engineers with a full suite of functions ranging from mixing and recording to adding effects like echo and reverb. They also range in price -- some are several hundred dollars and others are available free of charge. Most of these software packages provide the same basic set of functions. These include equalizing, editing and mixing. Let's look at each of these in turn.



In audio production, equalizing refers to tweaking the frequency levels on an audio signal. A good software package should allow engineers to do this to individual input channels as well as the overall mix. The software includes an interface known as an equalizer. Equalizers divide frequencies into segments called bands and usually range from 20 hertz (Hz) to 20 kilohertz (kHz), the range of human hearing. By tweaking the intensity levels for the frequency range of an audio signal, an engineer can emphasize or deemphasize certain pitches.


Methods for editing and mixing tracks vary from one software package to another. In general, most packages let you manipulate sections of a track or mix together multiple recordings to create the best final edit. Many packages allow you to cut, copy and paste sections of a track into a new format. Think your chorus should come in a bit earlier? No problem. Use the software's interface to shift it up a few measures.


Editing and mixing can also give engineers other options, such as adjusting the volume of particular channels or sections of the track, fading sound in or out or shifting sound so that it pans from one set of speakers to another.

One important task audio engineering software handles is working with MIDI data. MIDI stands for Musical Instrument Digital Interface, and is the standard by which computers, electronic musical instruments and other digital devices share musical information. MIDI isn't a music file -- it's a series of digital instructions that tell digital devices how to create a specific sound. Most audio engineering software can edit and mix MIDI data with other recorded audio formats.

How to Set up a Portable Audio Studio

Let's imagine that we have the opportunity to put together a robust portable audio studio. Which equipment do we choose? Which software packages are good choices? How much is it going to cost?


Assuming we aren't going to try and retrofit a current computer system, we'll have to start from scratch. Right from the start we have a choice: PC or Mac? There are several software applications available for both kinds of computers. There are PC and Mac laptops that have the horsepower we need to run an audio studio. The choice usually comes down to personal preference. Some people think that the best choice for people with little computer experience is the Mac, which as a reputation for being user friendly. Let's go with that -- we'll choose a MacBook Pro as our digital audio workstation.



To supplement the computer, we'll need an external hard drive. This is where we'll store recorded audio. By porting storage to an external drive, we free up the computer's resources to handle all the applications we'll be using when producing music. Audio files can be very large, so it's important to choose a hard drive with a lot of space. For example, we could choose the G-Tech G-Drive Q, which has 500 gigabytes worth of storage.


What about the software? We could go with a free software package like Audacity, but that means giving up on some features. For example, as of this writing, Audacity can't edit or mix MIDI data. We could use GarageBand, a popular Mac audio sequencer and audio processor. But compared with other software packages, it just doesn't offer a lot of features. If we want a really robust studio, we'll need something like Pro Tools from Digidesign. Applications like Pro Tools give engineers more control and options when working with sound files.


Once we settle on the software, it's time to think about audio interfaces. Not all audio interfaces are compatible with every software package. That's why we chose our software package first. So the first step in choosing an audio interface device is to make sure it will work with our DAW's software. Let's assume we're using Pro Tools and need a device with at least two analog inputs. Digidesign offers the Mbox 2, which not only has this capability but also comes with a copy of Pro Tools software.

On top of this, we'll need to invest in cables, microphones, headphones and speakers. If we want to produce music using the MIDI standard, we'll probably also need to buy a MIDI keyboard controller. While it's important not to skimp on these items if we want high quality sound, we won't necessarily have to break the bank either. Let's assume we pick reliable but affordable hardware.




The cost for the studio would break down like this:

DAW: our Macbook Pro would cost around $2,500
Hard drive: the G-Tech drive retails for $230
Software and audio interface: The Mbox 2 retails for $495 and comes with a copy of Pro Tools software
Other hardware: Reliable cables, headphones, speakers and a keyboard would cost about $800

The total cost for this studio is $4,025. While that's a healthy chunk of change, it's much less expensive than a traditional recording studio. We could always cut corners and choose more moderately-priced equipment and software, but it's true that you get what you pay for. If money is no object, we could spare no expense and buy the best equipment available. Then you'd really see a hefty bill.

No comments: