There are many factors that can effect the sound of your instrument, such as changes in temperature or your strings wearing out. If notice your cello sounds muffled, it might be time for a tune-up. Similar to a tune-up on a car, your instrument needs to be adjusted periodically in order to keep it running smoothly. Below is a list of adjustments you can make to improve the sound of your instrument. 

1. Replace your strings - Have you noticed you can’t achieve the same resonance you normally do, or you aren't able to get your strings in tune no matter how hard you try? It might be time to replace your strings. Over time, strings will naturally lose some of their resonance and ability to hold pitch. You should replace your strings once or twice a year to ensure that they don't go false. You may also want to try out a new type of strings to improve the sound of your instrument. There are many different materials used for the core and winding of the strings, which can significantly change the tone and response of your cello. I suggest high quality strings such as Larsen, Thomastik-Infeld, Pirastro, or D’Addario. 

2. Rehair your bow - Similar to your strings, your bow hair needs to be replaced once or twice a year. If you've lost a large amount of the hair on your bow, the hair has become discolored, or you're having a hard time getting your bow to grip the string properly, it's probably time for a rehair. You can get your bow rehaired by taking it to a professional luthier, a person who makes and repairs string instruments. .

3. Adjust the soundpost - It's important to make sure your soundpost is set up correctly and hasn't fallen. The soundpost is a wooden rod that's held between the front and back surfaces of the cello. You can check if it’s standing by looking inside the cello through the F-holes. Adjusting your soundpost can improve the clarity and power of your instrument. A luthier can help you move the soundpost around to get the best possible sound out of your cello. 

4. Straighten the bridge - A properly positioned bridge is essential to the sound and playability of the cello. It's important to check to make sure that the bridge is straight and in the center of your cello. If you notice your bridge is crooked, loosen the strings and gently pull or push it back into place. 

5. Eliminate wolf notes - A wolf note is an unpleasant warbling tone produced when a note matches the natural resonating frequency of the body of a cello. They usually occur around the notes E, F, F# or G. A simple way to eliminate a bothersome wolf note is by placing a rubber mute on the offending string between the bridge and tailpiece. If a mute doesn’t do the trick, you can install a medal piece of equipment called a wolf eliminator instead. 

 

Additional tips to keep your cello in peak condition:

- Rosin your bow regularly and remember to wipe the residue from the rosin off your instrument before putting it away.

- Always loosen your bow hair after playing by turning the screw to the left until the bow stick is no longer stressed. Be careful not to over-tighten the bow before use because this can warp the wood. The bow stick should maintain a natural arch when tightened the right amount.

- Avoid touching the hair on your bow. The oils from your skin will damage the hair and reduce its ability to grip the strings. 

- If you live in a particularly dry location, you can use a cello humidifier to protect your instrument from damage due to excessive dryness, such as cracking and warping. A cello humidifier is a soft rubber sleeve that encloses a sponge that you dampen and insert into the cello's F-hole. 

- Wrap your instrument in a silk blanket before putting it in the case. This will prevent the risk of scratches and help protect the instrument from the effects of changes of temperature and humidity. 

-  Don't leave your instrument in the car! Extreme heat or cold can cause your cello to fall out of tune, the varnish to melt, the glue to loosen, and the wood to crack. Furthermore, you don't want your instrument to get stolen!