Guitar players are used to hearing guitars on their recordings much like the way they were heard in the room. Professional studios have recording of these sounds down to a science. With the use of modern recording techniques, any sound desired by a player can be made audible. This however, wasn’t always the case. In the ‘50s, ‘60s, and ‘70s guitarists and studio engineers had to get “creative” with their production. This is a guide to the unorthodox recording techniques used in many famous recordings. In tandem with today’s technology, these techniques can yield a wide variety of sounds, and can open up a new palate of tones.
Microphone placement is key to getting the desired sound out of a guitar. Today, most studios will use a Royer 121 ribbon microphone as well as a good dynamic microphone such as the Shure SM57. These two microphones could not be more different in terms of tonal quality, construction, and price. But when blended together, they produce a full tone that sounds excellent on recording.
Not many people would put a condenser microphone behind an open-backed speaker cabinet. Because a speaker cone travels in two directions, a microphone placed behind a cabinet will record a sound. The tone of this placement will be noticeably "boomier" and "bassier" with less articulation, brightness, and high-order harmonics. This tone can be used on its own for a more atmospheric effect, or blended with a microphone input from the front of the speaker for a very full sound. When using this blending technique, it is important to remember to reverse the phasing on one of the microphones to compensate for the speaker cones traveling in opposite directions.
Another unorthodox microphone placement is far out in front of the amplifier to capture the sound of the room. Because condenser microphones often have a cartioid polar pattern, they will capture sounds from many directions. They are also very sensitive, so lower-amplitude frequencies will be more audible. It is important to remember that this placement will not give you the brightness and treble response of a microphone on the speaker cone. It will, however, give your recorded tone a natural reverb because it will pick up the reverb from the room.
Any audiophile will be able to tell you that analog tape sounds very different from digital files. Analog tape, in general, is noticeably warmer than a digital recording. Additionally, the distortion achieved when an analog tape machine clips the signal is not as harsh as digital clipping. Analog tape distortion can add a vintage flair to vocals and guitars (Think Aretha Franklin or Janis Joplin vocals).
Recording to analog tape is horribly inconvenient. In the world of editing, digital is far and away superior. For those looking to recreate the tone of an analog tape on their digital recording, there is a solution. Digital signals can be run onto an analog tape machine and then run back to the computer. One advantage to doing this is that once the perfect take is caught, the unreliability of magnetic tape will not be a problem. The level of the signal sent to the tape can be fine-tuned to get the perfect amount of tape distortion, and the warmer signal may be more pleasing to the ears of musicians who prefer the vintage vibe for their sound.
Do your research before investing in a reel-to-reel tape machine to be sure that it is compatible with your recording setup, and that it is operating at a useable capacity. Analog Tape machines are not mass produced as they were before music recording switched to digital formats, so a vintage tape machine may be your only option.
While we’re on the topic of distortion, guitar amplifiers can be used to distort instruments that we are not used to hearing distorted. One famous but often unrecognized example of this technique is with Justin Timberlake’s vocal track during the bridge of his 2006 hit "SexyBack". Timberlake’s vocals were recorded through a guitar amplifier to deliver a fuzzy, grimy tone. Jack White has also been known to deliver dirty vocals through a guitar amplifier using a harmonica microphone. Guitar amplifiers can be used for nearly any instrument. Like the analog tape machine, audio tracks can be sent out to a guitar amplifier and returned to the digital audio workstation via the microphone.
Don't have a guitar amplifier handy? No problem, try any of these software plugins that simulate amps.
Playing with Voltage
It is common knowledge that Jimi Hendrix would run his guitar pedals on dying batteries because the reduced voltage would produce a warmer tone. In the same way, Eddie Van Halen would run his Marshall stacks at a lower voltage to achieve more distortion. By reducing voltage, we reduce the efficiency at which our gear is operating, producing more distortion. I would not recommend imitating Eddie Van Halen’s techniques for the safety of you and your gear. Pedals however, are a different story. Danelectro produces a power supply called the Danelectrode which can vary voltage from 3-9 volts. This can yield a wide variety of tones for your recording or live performance. I would not suggest using this device on digital pedals because they will not operate properly, or may not operate at all. Overdrive, Fuzz, Distortion, and analog modulation and delay pedals with dropped voltage may give you the vintage tones which you have been searching for.
Playing with Time
Recording a song faster than performance tempo and slowing it down to drop the pitch used to be quite common in the 1970s. This technique can be heard on many Led Zeppelin recordings, including “Hey, Hey, What Can I Do.” The opposite of this was done to Bruce Springsteen’s 1980 hit, “Hungry Heart.” On “Hey Hey What Can I Do,” Plant’s vocals were recorded separately from the band, so Plant’s voice sounds comparable to his voice on other Led Zeppelin recordings. On “Hungry Heart,” however, Springsteen’s voice was sped up with the rest of the song, giving it a brighter timbre. Most digital audio workstations will allow you to play with time and pitch independent from one another. When one is dependent on the other, however, new, old, and interesting sounds can be achieved.
At the end of the day, your goal should be creating the sound that's best for you. Given the myriad of recording techniques at your fingertips, this article should only scratch the surface of all possibilities. Be sure to equip yourself with all the proper gear, and you'll be inventing a sound that's unique, and specific to your music style.