6. Choosing the Right Type
Firstly, figure out which type of capo suits your needs best. A screw mechanism comes in handy when using the capo across guitars with different neck thicknesses since it allows adjusting the pressure for each guitar. For quick performances, consider a spring-loaded capo or the spring-loaded variant with adjustable tension.
Tuning - Spring Tension
If you opt for a capo with a spring mechanism, it should match your guitar and its neck. If the pressure is too high, you'll need to retune each time you place the capo, eating up precious time. Unfortunately, the only way to determine the right tension is to test it with your own instrument.
String Buzzing
Another crucial factor is ensuring the strings don't buzz. With a capo offering adjustable pressure, finding the balance between eliminating buzzing and avoiding excessive pressure affecting intonation can be challenging. It's particularly tricky with a 12-string guitar, where each thick string has a corresponding thinner octave string. Applying enough pressure to make the thinner string sound clean might require more force, potentially affecting the intonation of the other strings. Usually, on a 12-string guitar, the thick strings need retuning due to their design.
As a general rule of thumb, the further the capo is from the fret, the more pressure it needs to apply for the strings to resonate cleanly without extra noise, increasing the risk of detuning. Hence, it's best to position it as close and parallel to the fret as possible without hindering your playing hand and thumb.
Fingerboard Curvature - Instrument Type
Capos are also distinguished by the shape of their upper arm, designed for curved or flat fingerboards.
Flat vs Curved Fingerboard
Curved fingerboards are typically found on classical (nylon-string) guitars, usually featuring wider necks. Acoustic guitars with steel strings (such as Western guitars) and electric guitars come with slightly curved fingerboards. While some manufacturers offer capos for both types, ensure you check the product description to find out which instrument type the capo variant is suitable for.
