December 2003

Recording Acoustic Guitar - Issue: December 2003

by Tim Crich

EQ
Properly miked, a quality well-tuned acoustic guitar with new strings should need little equalization. Perhaps to add some frequencies for sheen, or maybe to pull where the sound may mask other instruments.

When equalizing something with as many overtones as an acoustic guitar, pull the un-harmonic overtones and enhance the pleasing harmonics. This is when the musical recording engineer has the advantage. As a starting point, maybe:
- Roll off below around 82 Hz. The lowest note on the standard acoustic guitar is E, around 82 Hz.
- Sweep the low midrange, from 80 Hz to 300 Hz to find the boomy sound, then pull it using a narrow Q setting.
- Add somewhere between 80 Hz and 350 Hz for body, but only if there is room. Holding down the bottom end is normally not the acoustic guitar’s job.
- Add 300 Hz to 1 kHz for early harmonics.
- Add somewhere from 700 Hz to 1.2 kHz for more “wood” or pull here to ease the secondary harmonics.
- Add 1.5 to 3 kHz for presence. Pull for hollowness.
- Add 3 to 5 kHz for presence and attack.
- Add around 10 to 12 kHz for sparkle. It doesn’t take much to go from sparkle to brittle. Adding highs means adding noise.

Compression
The characteristics of an acoustic guitar might include wide dynamic range, semi-fast rich initial transients and substantial sustain. The acoustic may not have as many peaks as a snare drum unless the part is percussive, but it has peaks none the less. Closer miked sounds may need more compression than microphones placed a few feet away. Try:
- Attack. 10 to 20 ms. A very fast attack can control the initial attack transients of a sound.
- Release. Medium. Start at 250 ms and raise or lower as needed, depending on the tempo of the song.
- Threshold. Medium to high. A high threshold allows all the natural sounds and dynamics of the guitar to remain intact. A lower threshold might bring out more lower body.
- Ratio. Low, to begin with, maybe 2:1 or 3:1 dB of gain reduction. A higher compression ratio may be needed as a player may tend to move off axis now and again. Play with the ratio until the quiet bits as well as the loud bits can be heard. A higher ratio can increase the sounds density, so it fits in with other compressed tracks.

Choose to use two. If you choose to use two microphones on an acoustic instrument, often the one with more lows – usually the closest microphone – may need more compression than the distant one.

De-ess the guitar. Minimize fret squeaks and noise with a de-esser.

Defeat the proximity effect. Pull low end that may be created by proximity effect before sending the signal into the compressor or risk having the compressor react to the added lows, rather than the program.

Sympathy for the level. When the acoustic instrument is not in use, put it away, or loud levels in the room will cause it to ring out sympathetically.

Tim Crich has over 20 years of experience in the recording studio and has worked on records by the Rolling Stones, Bob Dylan, John Lennon, KISS, Billy Joel, U2, David Bowie, Bon Jovi, Ozzy Osbourne, Cher, Byan Adams and many more. He has engineered for some of the biggest producers in the world. This article is excerpted with permission from his book Recording Tips For Engineers.

In-Ear Monitoring – refining your mix - Issue: December 2003

by Fred Michael

Today, I want to enlarge on the topic of IEMs, with a focus on ways to enhance the experience for the performer while protecting their ears as much as possible.

It’s important to remember that IEMs are not only an excellent way to hear onstage; they also provide ear protection when used properly. However, the opposite is true as well: exposure to poorly set-up IEMs can accelerate hearing loss. An example of this is when you see vocalists performing with one of their IEMs pulled out. A closer look at this phenomenon is a good starting point for our discussion.

This situation is really the “worst of both worlds” and should be avoided. The musician has, for reasons I’ll explain, removed himself from the protective in-ear environment and is trying to get comfortable with a blend of the in-ear mix and the sound on stage. The problems are three-fold: the in-ear mix is now essentially useless, the onstage sound has probably not been set up for their vocal mix, and there is an increased risk of hearing damage.

Usually, the performer removes one of their monitors because the mix they are getting is completely out of whack, taking them out of the music rather than engaging them. Like a swimmer coming up for air, the performer does the one thing he knows will help. If you see this happening with your group, you need to take a look at your mixing techniques. First of all, allow time at sound check to set up a proper instrumental blend in their mix. The vocalist needs enough support from the instruments and other voices to get a tuning reference, but not so much that their voice gets lost.

Ask the performer which instruments they usually gravitate towards for a tuning reference and start your sound check with an emphasis on those. Remember, this is all about getting them comfortable in the IEM environment; that doesn’t necessarily mean you are building a CD-quality mix; rather, you are starting with the essential elements for the performer to feel comfortable and stay in tune. For some, this means a bare bones sound with dominant vocals, others want everything; experience will tell you what is needed.

Another factor that tempts performers to remove their monitors is the subjective feeling that the mix inside their head is very artificial sounding, removed from the “real” sound onstage. Again, the performer feels isolated and pulled out of the music. Most IEM engineers use ambience microphones to help their musicians stay connected to the stage sound. Usually, this is a matched pair of microphones, placed at stage left and right, and aimed in such a way to get a representative room sound. This is then blended into the mix, making it much more natural sounding. While you may not have the resources to purchase dedicated ambience microphones, any decent-quality stereo recording microphone will approximate the effect. Play with different locations until you have a couple of options to choose from.

Finally, avoid mixing to a level that irritates the performer; this is an alarm saying, “Turn it down!” Properly fitted IEMs, whether custom or generic moulds, can reduce the ambient volume by 15-20dB; this gives you all the latitude you need to build a comfortable, satisfying mix while minimizing risk of hearing damage. Never let your performer use standard ear buds as replacements for IEMs; they do not provide the isolation required for safe use of this technology in the live concert environment.

Fred Michael is President of Rocky Mountain Sound Production Services in Vancouver, BC. Fred can be reached at fred@rmsound.com, or via the Rocky Mountain Sound Web page, www.rmsound.com.

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