How To Make An Acoustic Guitar Sound Warmer

One reason acoustic guitars are so popular is the range of tones you can get from them, depending on body size, materials, string choice, and playing technique.

If you’re new to playing and have a particular sound in mind, you might be curious about how to make an acoustic guitar sound warmer.

The fastest way to make an acoustic guitar sound warmer is to change the strings to phosphor bronze strings, as they were designed for warm tones. You can also switch out your nut and saddle material, modify your technique, or, if you’re playing amplified, try EQ adjustments.

Let’s look at what we mean by a warm tone and a few ways you can try to give your acoustic sound a rounder, warmer timbre.

Why Are Some Acoustic Tones Warmer Than Others?

Before we go too far with explaining how to change things, it’s helpful to understand some basics when it comes to tone.

Most people can hear sounds when their frequency is between 20 Hz — the scientific measurement of vibrations per second — and 20 kHz. That range can be divided into sections based on some common characteristics.

• Super Low End, 16 Hz to 60 Hz: This is the bottom of the frequencies people can hear, and in some cases, this range is felt as much as heard.
• Low End, 60 Hz to 250 Hz: This is what people are talking about when they want bass — low notes that you can hear but still resonate deep in the chest.
• Low Mid, 250 Hz to 2 kHz: This is the area of the frequency spectrum where many of the guitar’s fundamental frequencies live. This is the part of the spectrum we want to really emphasize when looking for warmth.
• High Mid, 2 kHz to 4 kHz: Where low mids are warm, high mids are bright. You want to de-emphasize the high mids somewhat in search of a brighter sound, but if you take away too much, you won’t be warm, you’ll be muddy.
• High End, 4 kHz to 6 kHz: The high frequencies can impart a sense of presence to an instrument, but when you’re seeking a warmer tone, you have to be cautious, because too much high end can sound harsh or tinny.
• Super High End, 6 kHz to 16 kHz: The very highest range is mostly overtones, so things like string choice and nut and saddle material will have a much greater impact than playing technique.

When we talk about a warm acoustic guitar tone, we mean a sound that has a nice, full, mellow bass sound without being too boom-y or echo-y and without the sharp, bright higher end sound often associated with acoustic playing.

How Do I Warm Up My Acoustic Guitar Tone?

As I noted above, the single biggest change you can make to get a warmer guitar tone is changing strings. We’ll look at the specifics of that in a bit, but strings aren’t the only option when it comes to getting a warmer tone.

How To Get A Warmer Acoustic Tone With Playing Technique

One very basic change you can make is to switch up your playing hand technique. A gentler, more tangential position when hitting the strings can really change how things sound, for example.

To see what I mean, try this. Pick up your guitar and hold your playing hand so your thumb is parallel to the strings.

Move your thumb up and down at the bottom joint, and move your hand closer to the strings. When the outside corner of your thumb hits the low E string, it sets it vibrating relatively gently.

That cuts back on the percussive noise of the string and limits the higher overtones that are produced.

Now move your hand so the tip of your thumb is what hits the low string. That causes a much more pronounced vibration, and if your set up isn’t right, it might even cause buzzing against the frets, the nut, or the saddle.

That, along with the initial acceleration, help create higher overtones and give a somewhat brighter timbre, even when playing the same note.

Another playing option that can give you a warmer sound is your pick choice. In general, softer material for a pick will give you a warmer, rounder sound.

To give you an idea of the difference, this video shows three different picks, each designed for a specific tone enhancement — bright, warm, and deep.

If you want the mellowest possible sound, you could even try using a felt, leather, or rubber ukulele pick. You need to be careful to have

The final technique change you can make has to do with where you play the strings. As in the first technique example, it’s amazing to see the difference this can make.

To see what I mean, fret a chord and strum with your pick as close to the saddle as possible without touching it, then strum again just below the end of the fret board. Again, the characteristics of the vibration affect the timbre of the sound, even when playing the exact same pitches.

What Components Give You A Warmer Acoustic Guitar Tone?

One complaint many new players have about inexpensive acoustic guitars is they have a bright, sometimes shrill tone. While string choice is probably the largest contributor to whether the tone is warm or bright, other parts play a role, too.

In particular, the nut and the saddle of the guitar, which are the two main vibration points, contribute to the tone. Inexpensive plastic can sound very harsh, and that is the most common material for nuts and saddles on low-end guitars.

A switch to bone will often produce a warmer, more mellow and full tone while also helping with note-to-note articulation.

What EQ Settings Give You A Warmer Acoustic Guitar Tone?

We’ve covered using EQ to give yourself the best possible acoustic guitar tone, and many of the tips we went over there apply here, as well.

In general, when people refer to a warm sound, they mean one that has a lot of frequencies in the lower part of the low mid range, between about 300 and 800 Hz. You can boost this area to make things warmer or you can cut from the super high end, between 6 kHz and 8 kHz, which gives a similar effect.

You need to be careful when applying EQ settings, though. Too much of any frequency is not good.

Just like too much in the high end and super high end can make things sound too bright and even shrill, too much in the low end and the low mids can make things sound muddy.

One reason is there is less dynamic range the lower the frequency so that part of the spectrum can get crowded quickly.

How you apply the EQ settings will depend on a range of things. If you’re recording the guitar, then your microphone choice, mic placement, and what effects you have access to will push you in a different EQ direction than if you’re performing live through an amplifier or a PA system.

Which Guitar Strings Should I Choose For The Warmest Sound?

As I said at the very start, and as is probably obvious to most guitar players already, the strings you use are going to have the biggest impact in whether you have a warm or bright tone.

We’ve looked at some of the choices you have when it comes to warm guitar strings in the past, but let’s recap briefly.

You have the choice between winding type, with flatwound strings generally being warmer than roundwound strings. Relatively few brands make flatwound strings for acoustic guitars, but some are available.

A compromise is so-called flat top strings, which are roundwound strings that have been polished, giving them a smoother texture.

After winding type, you need to decide on string composition. Nylon or gut strings, the first kind used on guitars, offer a much rounder and warmer sound than steel strings, but are also far quieter.

For the most part, only electric guitar strings come in nickel plated steel, pure nickel, or stainless steel, but they can be used on acoustics. They will offer a far brighter tone than traditional acoustic strings and could also put more strain on the guitar.

Most acoustics come standard with 80/20 bronze strings, which are made up of 80 percent copper and 20 percent zinc. They are less bright than stainless steel or nickel strings but can still be quite bright.

Phosphor bronze strings add phosphor to the 80/20 copper/zinc mix as a way to increase the life of the strings by reducing oxidation. That results in a far warmer sound than traditional acoustic strings.

Finally, silk and steel strings are a compromise between nylon and metal strings. They are far lower tension than traditional metal strings and offer a mellower, warmer tone, as well.

The trade off, as with nylon strings, is lower volume compared to other strings.

Conclusion

Remember when thinking about getting a warm acoustic tone that there are some factors that can be changed, while others are set for as long as you have the guitar.

You can switch strings, saddles, or the nut fairly easily, for example, while adding a pickup, or a preamp so you can make EQ changes, is more involved.

The body shape, the size, and the woods used, all of which have probably the largest impact on the how warm the tone can get, are obviously fixed.

If you have a particular tone in mind, then it’s worth spending some time trying out guitars with different wood and body combinations to see what sounds closest to what you’re looking for.

A Gibson-style jumbo guitar with maple back and sides will be much brighter than a small bodied, all mahogany guitar, for example. Finding a guitar that suits your needs from the start will help you get exactly the tone you’re aiming for.

James Kelly

I’ve been a musician, particularly a guitarist, for more than 25 years. I love writing about guitars, gear, recording, music in general and more.