It's possible to capture a great acoustic guitar sound in your home studio with a little know-how, informed equipment choices and of course, a stellar guitarist. Here's a helpful guide on how to prepare and set up your acoustic guitar and space to capture the magical moments.
Creating an amazing guitar recording begins with an excellent guitar. You could have the best studio in the world, but if your instrument isn't a good quality instrument, it's going to be a challenge to record the sound you want. Start with investing in (or renting) a good acoustic guitar. Taylor, Martin, Takamine and Yamaha are a few brands that all produce high-quality acoustic guitars. I also recommend researching local guitar luthiers, there might be gem of an instrument out there just waiting to be discovered.
D'Addario guitar strings (http://www.daddario.com/)
Once you've found your instrument, the next step is to choose the appropriate gauge of string. Lighter gauge strings are easier to play and bend, but a heavier gauge string will provide a bigger sound and sustain for a longer period of time. If you choose a thicker string, be sure to have your guitar professionally set up to accommodate for the heavier gauge strings. The three main types of strings for acoustic guitars are bronze, phosphor bronze and nickel wound; each type of string produces a slightly different tone. D'Addario is a reputable brand who are known for producing acoustic guitar strings that sound warm, bright and well balanced. Be sure to choose the gauge and string type to suit the style of the record you're creating.
It's going to be important that you tune your guitar correctly before you begin recording. You can either use a conventional electronic tuner, or better yet, one of the new iPad apps that are available on the market. I like to use Guitar Tuna, a fun and accurate free app for iOS and Android. Keep your tuner close by during your studio session for quick tune-ups between songs.
If you're using a pick, the pick's thickness is going to have an impact on the overall sound. It's a good idea to have a few picks on hand with varying thickness. Generally, I find picks that are thicker sound best for picking, and thinner picks work well for producing pleasant tones for strumming.
The environment you record in is going to have a big impact on your overall sound. When recording acoustic guitars, you'll want to capture not only the sound of the guitar itself, but also the sound of the room. This will help to add character and a sense of space to your recording. When recording acoustic guitar, include the natural reverb of the space you're in. One way to easily do this is to position the mic a few inches back from the guitar. This approach will produce better results than adding in artificial reverb to the acoustic guitar tracks in the mixing stages.
If your recording environment is fairly dead sounding, you can liven it up by adding reflective surfaces. The sound from the guitar will bounce off the surface, and create audible reflections. Try to position the guitarist so that his/her sound can bounce off floors, doors or surfaces. If your room is overly live sounding, you can use an acoustic gobo to absorb and diffuse sound waves. A gobo is a movable acoustic isolation panel; they are typically constructed from wooden panels, and then covered with foam, carpeting or other sound damping material.
A Royer Mic in action.
Your choice of microphone will determine the overall sound of the recording. Small condenser, large condenser, dynamic mics and ribbon mics will all give you drastically different results.
Small diaphragm condenser microphones are useful for close miking, and will reproduce the guitar's sound in full detail. They may also color the sound a little less, giving you a more accurate recording of the guitar itself. A large diaphragm condenser microphone is a good choice if you're going to include the room sound in your recording. Overall, condenser microphones are quite sensitive, and are generally placed a few inches or more back from the guitar. Dynamic microphones are less sensitive, and need to be placed closer to the guitar to achieve the necessary volume level. A good ribbon microphone will give you a natural sounding acoustic guitar recording, although you may need to roll off a little low end. Ribbon mics can easily over-emphasize the low end of a sound source if they are positioned too closely to the guitar. You may also need to use a microphone pre-amplifier in combination with a ribbon mic to boost the signal.
It's fairly common to see guitars miked closely in live environments. In most cases when you're recording in your home studio, you'll want to record your guitar from a little further back. One of the most popular ways to record the acoustic guitar is to position the mic between the neck of the guitar, and the body. The mic can be angled back towards the end of the fingerboard (close to the body of the guitar) but should not be pointed towards the sound hole.
This is a good position to begin with, as you can balance recording the sound of the body and neck of the guitar, and sound of the strings. The tone produced by the acoustic guitar is generated not only from the sound hole, but also from around the bridge area, where the fingerboard joins the body, as well as the top and back of the guitar.
Before you begin recording, try to spend a few minutes with your guitarist and experiment to find the ideal microphone position. Simply put your headphones on, move around the mic around to find the 'sweet spot', and then leave the mic where the guitar's tone sounds sounds best.
Another popular position is to move the mic closer to the bridge; but just below and behind it. This can produce a tone that is somewhat more edgy, although you do have to be careful that the guitar player's right arm doesn't overshadow the high frequencies. You also have to watch out for excessive pick noise in this position. Once again, let your ears be your best judge.
If the guitarist is finger picking, you may want to consider miking the guitar closer to the instrument's bridge. You can also try to position the mic slightly above or below the guitar to capture slightly different tones.
Since every guitarist, guitar, recording environment and session is unique, there's no one right or wrong 'universal technique' for recording acoustic guitars. The key is to make good use of your resources, and do try to find the best quality guitar, strings, and mic for the recording. Your recording environment also plays a big part in the overall sound, so if you're in a home studio space you will have to be creative to create an ideal recording environment. With a little practice and careful listening, you'll be able to record amazing guitar tones.