Inputs and Outputs

Inputs and Outputs

A studio setup won't get far without the ability to get sound in and out of the electronic and digital domains and connected to the computer. Additional hardware gives physical control for the virtual parameters of software. We'll start building our studio by assembling the gear we need for inputs and outputs. The ultimate goal is a complete creative workspace, as shown in Figure 2.1 .

Figure 2.1. A fully equipped, computer-based studio in action. M-Audio ( set up this studio, so it features its products. Notice that even this digital audio manufacturer still uses some vintage keyboards. (Photo courtesy M-Audio)

Transducers (microphones, monitors , headphones) are essential for getting sound in and out of the electronic domain.

A separate control room isolates the recording area from the sound of the computers.

Keyboards shown here include keyboards with sound production abilities and instruments designed for controlling soft synths, such as this USB- powered M-Audio Radium.

Control surfaces with banks of knobs and sliders, like the Evolution US-33e shown here, provide remote access to software parameters (see p. 55).

An audio interface, like the M-Audio FireWire models shown here, gets audio in and out of the computer (see p. 50).

External hardware like these vinyl turntables and cross-fader are great for those times when software just doesn't feel and sound the same as analog equipment.

Make sure you have a computer capable of running audio software (see p. 60), and an application for recording and hosting software instruments and effects (see p. 71). Shown here are Apple PowerBooks running Ableton Live.

Recording and Playback: Transducers

As explained in Chapter 1, electronic music systems of any kind, analog or digital, must use transducers to convert sound to and from vibrations in the air. For example, to play back sound, you'll need studio headphones and/or speakers , and you'll need microphones for recording.

Gear vendor examples:

Shure (

M-Audio (

Edirol (

Tapco (

Event Electronics (

Mackie (

Sony (

Sennheiser (


Make sure your playback equipment is "pro." Pro devices are very different from consumer models, even those in the same price range. Consumer audio equipment is often intentionally "sweetened," emphasizing certain frequency ranges, because that's what consumers are accustomed to hearing. That's a disadvantage when you're trying to adjust your audio mix for a wide range of equipment, so pro "studio" models are designed to be truest to the original sound.

Prices on all these products range from a few dollars to tens of thousands of dollars, but that doesn't mean you won't find inexpensive workhorses in pro studios . See Table 2.1 for help identifying pro-level equipment that won't break the bank.

Table 2.1. Recording and Playback Gear: Where to Start


What You Need to Know

Starting Price Range

Basic Examples

If you're recording directly in stereo, you'll need a matched pair of microphones or an integrated stereo mic.

Match microphones to intended use: an inexpensive, rugged vocal microphone might be better for adding live vocals in a club than a pricey studio condenser.

$100 buys a standard pro dynamic microphone; condensers have dropped to under $200 but higher-quality models cost more.

Shure SM57 (pictured) and Beta 58A, and related models are good general-purpose percussion and vocal microphones.

M-Audio makes entry-level dynamic and condenser microphones ideal for computer audio use.

Passive monitors are unpowered and require a separate amplifier . Active monitors are powered, self-contained units.

Check prices carefully : monitors are often listed per unit instead of per pair, a bit like a one-way airplane ticket.

Decent active entry-level monitors start at around $200 a pair; for serious studio work, consider the $400500+ "mid-range" models.

Beginning users can opt for speakers from M-Audio and Edirol. Mid-range options include: Tapco S3 Event Electronics TR-8 Mackie HR824 (pictured)

Some studio headphones are available in alternate DJ models. They're more rugged and allow easier one-eared listening.

Many "starter" headphones around the $100 price point are also standards in the studio.

Sony MDR-7506 Sennheiser HD-280 (pictured) AKG K-240S

Computer Audio Interface

The line-in and headphone jacks on your computer are fine for occasional recording and listening, but dedicated audio/MIDI interfaces like the one shown in Figure 2.2 offer higher audio fidelity and more connection options. They might also feature extras like bundled software.

Figure 2.2. A hardware audio interface, such as this Edirol FA-101 Firewire interface, shown here in front and rear views, will be the primary connection between your computer's audio software and the outside world. (Photo courtesy Edirol)

Why not just use the audio I/O built into your computer? First, these interfaces usually lack the number and size of connections you need, and rarely accommodate the lower signal level generated by guitars, microphones, and turntables. Some computers lack sound inputs altogether. Second, built-in interfaces tend to be too noisy for recording, especially if they're not properly insulated against interference and computer noise. In addition, their dynamic and frequency ranges often aren't as good as those of dedicated audio interfaces.

Interfaces for every budget and need are readily available, so your primary job is to navigate three essential elements on the specifications sheet: inputs and outputs (I/O), digital-to-analog (D/A) and analog-to-digital (A/D) conversion quality, and the means by which the device communicates with your computer ( bus ).

Audio Interface Checklist

Identify your needs and keep these elements in mind when you're buying an audio interface:


  • Enough inputs for instruments, inputs and preamps for microphones

  • MIDI connection for MIDI devices (if needed)


  • Standard stereo pair

  • Multiple outputs for surround sound

  • Extra output for cueing (DJs only)

  • Extra output for alternate mixes for other musicians

Adequate resolution

  • 16-bit, 44 kHz sample rate for everyday use

  • 24-bit bit depth and 48 kHz, 96 kHz, or 192 kHz sample rates for high-quality capture (see Chapter 1, "Understanding Digital Sound")

Right bus for your computer

  • Laptops: CardBus, USB 1.1/2.0, or FireWire

  • Desktops: USB 1.1/2.0, FireWire, or PCI

OS compatibility

  • Drivers available for your OS of choice


  • Software bundles and hybrid devices (keyboards with integrated audio/MIDI interfaces or audio interfaces combined with control surfaces) can add value.

Ins and outs of I/O

Since one of the primary reasons for buying an interface is to add additional inputs and outputs, you'll want to first think about what equipment you have and how many inputs you'll need to record simultaneously . For instance, if you're a vocalist playing an external keyboard, you'll need one input for the vocal mic and two for the external keyboard, for a total of three inputs. If you need surround or other multichannel outputs, you'll also need multiple simultaneous outputs beyond the standard two-channel stereo. See Table 2.2 for some of the most common setups.

Table 2.2. Typical Analog Audio Configurations

Number of Analog Connections


Two in, two out

Digidesign Mbox; Mackie Spike

Four in, four out

M-Audio 410; Lexicon Omega (

Eight in, eight out

MOTU Traveler (; Edirol FA-101

Extras: All these interfaces also include digital I/O, and the 4x4 and 8x8 devices add MIDI.

Aside from analog audio I/O, other connections are necessary for hooking up specific MIDI and digital equipment:

  • MIDI: If you have equipment with standard MIDI connections, you'll need either an audio interface with a MIDI connection or a self-contained MIDI interface.

  • Digital Audio I/O: For a higher-quality audio signal and synchronization, digital audio equipment often includes digital as well as analog connections.

Chapter 3 explains different connection types and how to manage them.

Missing MIDI? Simple 1x1 MIDI interfaces like the M-Audio Uno have MIDI at one end and USB at the other.

D/A-A/D conversion

Specifications for bit depth and sampling rate are significant to audio quality, as explained in Chapter 1, although 16-bit 44.1 kHz is sufficient for most users. The quality of the digital audio circuitry itself plays a considerable role as well, so you might want to check the reviews of an interface you're considering in pro audio publications like EQ and Sound on Sound . Some pros even purchase pricey stand-alone D/A converters, although those with home studios are more likely to use the converters built into their interface.

Myth dispelled: Many users assume FireWire is "better" than USB 1.1, but that's not exactly right. With well-written drivers, USB 1.1 can perform quite well in recording and playback. FireWire simply has greater bandwidth than USB 1.1, allowing more channels.

Connecting to your computer

Different interfaces connect to the computer via various connection types, or buses , such as FireWire and USB ( Table 2.3 ). Based on available bandwidth, buses can offer multichannel audio with nearly real-time performance. (Faster buses allow more channels.)

Table 2.3. Buses for Audio

Name /Alternate Names

Used for





Extremely compact laptop audio interfaces

Echo Audio Indigo (see Figure 2.3 ) (



PCI/PCI-X (high-speed variant)

Inexpensive desktop interfaces and high-end, high-bandwidth multichannel systems; especially popular on PC platform

Digidesign Pro ToolsHD platform (high end) E-mu interfaces (budget) (

Both Laptop and Desktop


FireWire 400/FireWire 800 (high-speed variant) Also called IEEE-1394

High-bandwidth multichannel audio; appears on some external audio gear

Metric Halo interfaces (

USB 1.1(Most common variant of USB)

Lower-bandwidth multichannel audio; connections to control surfaces and some MIDI gear

Lexicon Omega

USB 2.0(High-speed variant of USB)

High-bandwidth multichannel audio

Edirol UA-1000

Figure 2.3. Echo Audio's Indigo cards fit into the CardBus slot on many Mac and PC laptops. (Photo courtesy Echo Audio)

Bundled software

Digidesign has always sold its hardware and software as a single bundled package, from its entry-level Mbox to its high-end Pro ToolsHD. But other vendors also typically sweeten their audio interface packages by including free software. These are often limited editions rather than full-blown versions of the software you'd buy separately, but they can be a good starting point. Bundled software includes packages like Pro Tools LE (available via Digidesign only), the full versions of entry-level audio workstations like Mackie Tracktion and Steinberg Cubase LE, and limited editions of programs like Propellerhead Reason and Ableton Live.

Controller Input Devices

You can make music on a computer using just a mouse and QWERTY keyboard. Applications like Ableton Live and Apple Logic even let you type on your keyboard to play instruments. But for more tactile feedback, controller input devices let you assign onscreen settings to physical knobs, faders , buttons , and piano-style keyboards ( Table 2.4 ).

Table 2.4. Options for Hands-on Control



What you'll need


$100 $150


Shuttle through a mix with ready access to keyboard shortcuts

Custom keyboard or shuttle controller

Logickeyboard ( Contour Designs ShuttlePro (pictured) (

$150 and up


Manipulate software parameters

Basic control surface with knobs and/or faders

M-Audio Evolution UC-33e fader box or DJ-oriented X-Session (pictured) FaderFox for Ableton Live and Mackie Tracktion (

Play a software instrument while adjusting sound parameters

Keyboard with knobs, faders, or other controls, either with a USB or MIDI interface

Alesis Photon x22 ( Novation X-Station including built-in synth and audio interface (pictured) (

$800 and up


Control your mix with motorized response to automation

Motorized control surface

JL Cooper controller line ( Mackie Control Universal (pictured)

Interface/software bundle vendor examples:

Digidesign (

M-Audio (

Lexicon (

Steinberg (

Mackie (

Hybrid Devices

With all the devices available, you could wind up with a lot of different pieces of equipment. So to reduce complexity and cost, manufacturers increasingly are combining functions into integrated devices ( Table 2.5 ).

Table 2.5. Hybrid Hardware Examples



Best for

Audio interface + keyboard + control surface

Alesis Photon X-25, M-Audio Ozonic, Edirol xx

Musicians playing soft synths on the go

Audio interface + motorized control surface

Yamaha 01X, Tascam FW-1884 ( Figure 2.4 ), Digidesign 002

Integrated home studios and mobile recording

Audio interface + mixer

Mackie Onyx, Alesis MultiMix USB

Project/home studios that need to route and mix lots of external gear

Figure 2.4. The Tascam FW-1884 combines a motorized control surface with a multichannel audio interface to turn your computer into a fully powered recording workstation in one device. (Photo courtesy Tascam)

Real World Digital Audio
Real World Digital Audio
ISBN: 0321304608
EAN: 2147483647
Year: 2006
Pages: 96
Authors: Peter Kirn

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