Analyzing the weaknesses in a home studio

Invariably the audio recording message boards are full of new users asking questions about equipment purchases.  Which sound card, pre-amp, speakers, software, etc. should I buy?  The cheap availability of recording gear has made it possible for anyone to jump into the recording engineer position at home, without any knowledge of acoustics or electronics required.

There are, however, many advantages to having background education in electronics and / or acoustics and without this information anyone can easily be sucked into marketing hype and spend their hard earned dollars on equipment they do not really need or cannot fully utilize.  This article will attempt to roughly outline the paths from instrument to computer and back to your ears in order to determine the weakest links and point the new home studio owner where to direct the majority of their money.

The Signal Path

From performance to finished product, there is a basic signal path that all studios follow.  The performer plays an instrument of some sort, which makes it’s way into your computer’s software either directly in the case of MIDI and virtual instruments, or through conversion processes in the case of analog or acoustic instruments like drums or a guitar.  Similarly, it will follow a path from the computer, through conversion processes and back into the air as sound from speakers.  Each step in the process has associated equipment and varying effect on the quality of signal your going to record or hear.

Analog Recording

This table outlines the basic blocks of recording an analog signal and it’s associated frequency response and distortion potential

	Signal Point	Frequency Variation, 20-20,000	Distortion
In	Untreated Room	Easily +-20dB variations, highly variable	N/A, depends on frequency / phase variations and ambient noise
	Microphone	+- 10dB, varies greatly by mic type and placement	Up to or greater than 10%, depending on mic type and frequency measured
	Mic Pre	+-1dB or better	<1% typical, orders of magnitude smaller possible
	A/D Converters	+-1dB or better	<1% typical, orders of magnitude smaller possible
	DAW Processing	+-0 (bit for bit)	0% (bit for bit)
Out	D/A Converters	+-1dB or better	<1% typical, orders of magnitude smaller possible
	Analog Mix / Amplification	+-1dB or better	<1% typical, orders of magnitude smaller possible
	Monitors	+-3dB at best, ignoring low frequency limit	Up to or greater than 10%, particularly near low frequency limit
	Untreated Room	Easily +-20dB variations, highly variable	N/A, depends on frequency / phase variations and ambient noise

Digitally sourced signals will skip the input side entirely, limiting all opportunity for frequency and distortion characteristics to the samples or synths used.  However, the output portion still applies when it comes to actually hearing what is being mixed or mastered.

Weak Link Analysis

A quick look though the table should make should make it very easy to determine where your money should be concentrated first:

• Your recording and monitoring room can attribute a huge amount of frequency and phase response distortion as well as ambient noise that travels all the way through from track to finished product.  This applies equally to the monitoring environment and leads to poor mixes due to not being able to hear what you are trying to mix properly.
• The second weakest parts of the chain occur during the transitions from sound pressure to electronic signal or vice versa.  Microphones and monitor speakers are your #2 priority.
• Everything electronic in the signal has a relatively insignificant effect and will have smaller return on investment while climbing the dollar signs up in quality levels.

This is not to say that the electronics involved are not important, just that they are not as important as you may think (or will be led to believe by marketing).  For example: A stellar, well positioned microphone in a well treated room recorded through a cheap pre-amp and a consumer “Soundblaster” compatible soundcard will yield far better results than a crappy microphone haphazardly placed in a untreated room recorded through the best pre-amp and converters in the world.

Attacking Number 1, the room

Entire volumes of books have been written on acoustics, and properly addressing room issues is potentially very expensive.  But with some small tweaks, you can minimize the effects of a poor room.

• Room dimensions matter.  A square room, or one with even length width or height proportions will give you lots of standing waves with lots of cancellation and hot spots.  Avoid using these dimensions as your tracking or monitoring space.
• Learn what treatment works for your problems.  Read up on absorption, diffusion, and bass traps.  Implement as many as you can affordable.  Hint… “egg shell” foam does nothing but provide a fire hazard.
• Record things with the microphones close to the source and away from walls and other reflecting surfaces.  That will minimize room effects like cancellations from reflections and standing waves.
• Use near field monitoring and place them properly.  Your two monitors and your head should form an equilateral triangle, there should be no interference between your monitors and your ears, and they should be away from walls to avoid reflections.

Some excellent resources on home made bass traps and other acoustic treatments are available on the Real Traps web site.

What about headphones?

Headphones do eliminate the interaction of the room, but they will obscure the stereo effect of regular speakers a bit.  Your brain depends on the interaction between signals reaching your left and right ear for positional cues, something you may not be able to properly place using headphones alone.  That being said, headphones are a perfect solution to a bad room that cannot be avoided.  However, they do apply as monitor speakers, so the important criteria in the next section applies to them.

Attacking number 2, microphones and speakers

In both of these fields, there is a curve in quality vs. cost leading to a great many cheap but nearly useless solutions on one end to way more expensive than it’s worth on the other.  Generally it is important to spend as much as your budget will allow on microphones and monitors.

For Microphones:

• Use a type appropriate for what your trying to record, i.e. a dynamic like the Shure SM57 on a guitar cabinet.  A small diaphragm condenser pair as overheads on a drum kit.  A large diaphragm condenser for a vocalist.  There are no real hard rules on these, but a good starting point will result in saved time.
• Position it properly!  Where you place the mic is easily as important as which mic it is.

The SAE institute has some excellent published articles on microphone types and placement for drums and guitars.

For Monitor speakers:

• Choose a speaker appropriately sized for the material you wish to mix.  If you’re doing something with a fair amount of low frequency content (house / techno / hip-hop) then you will need larger sized woofers.
• Set them up properly! This is very important and was addressed in the room section as well.
• If you need to add a subwoofer, make sure to position it well and calibrate it to the correct level.

Finally, the electronics and software

This may be a contentious point among studio owners, but I truly believe the electronics should focus on functionality and reliability first, and subjective sound quality last.  First and foremost, they must work and keep working!  The differences in sound will be highly subjective and everyone will offer their opinions based on hard to define words like “airiness”, “clarity”, “space”, “openness”, and any number of other feel good adjectives.

• Pre-Amplifiers should be picked on how many you need and the requirements of your studio.  Much of the time, these are now built into the converters as a whole unit.  Pre-amplifiers will impart a subtle sound to the recording so it is best to avoid the bottom of the price spectrum.  The top of the price spectrum gets equally ridiculous though, so a good middle ground compromise is best.
• A/D and D/A conversion, AKA the “soundcard” or interface.  This should be picked based on manufacturer support and driver development for your computer’s operating system.  A great sounding card with crappy drivers will do you no good.  Other things to consider are number and type of inputs, and future expandability.
• Software should be what you are familiar with or are willing to learn.  This should also be designed around your computer preferences, i.e. Mac vs. PC.  Generally, DAW software is a highly competitive area and every vendor is watching the others very closely to not be left behind.  With time, most of the packages will yield you great results once you’ve learned how to use them.

In conclusion, home studios looking to improve the quality of their product should begin by looking carefully at their recording environment  acoustics, followed by their microphone choices and placement, then their monitoring setups.  These should be the focus of your budget first, before climbing the ladder on upgrades of your pre-amplifiers, converters, or general audio interfaces and even the DAW software itself.