How to Choose an Acoustic Guitar Amplifier

Ordinarily an amplifier’s job is to make a guitar sound louder, but when amplifying an acoustic guitar, it gets a little more complicated than that.

With a solid-body electric guitar, the amplified sound is intended to be completely different when plugged in. With an acoustic guitar, you want the sound to be louder but not different. The amplified acoustic sound is meant to supplement your acoustic guitar’s natural tone and volume, filling the room but not overpower the guitar, unless you intend it to, while directing the sonic focus of the audience to the performer and not the speaker cabinets.

And that’s not the only difference. Here’s a look at the considerations and options available to acoustic players who are looking for more volume and presence, without going electric.

Amplifying Parlor vs. Jumbo Guitars

How well your acoustic guitar projects sound is a significant consideration when shopping for an acoustic guitar amplifier and determining how much power you will need.

A jumbo acoustic guitar is built to be heard and will project well. With a guitar of that shape and style, the acoustic amplifier you choose won’t need to be very powerful in most instances. However, a parlor acoustic guitar is much smaller and has a much softer in sound, no matter how loudly you strum. Consequently, if you play a smaller-bodied guitar, you would need more amplification to be heard over the larger guitar or in a larger room.

If your acoustic guitar has a built-in 9-volt battery box, volume or EQ controls, that means you are already equipped with a pickup and a pre-amplifier, an electrical system that sits between the pickup and the amplifier, raising the output of the pickups and the amplified sound of the guitar. If not, you also are going to need to select an acoustic guitar pickup.

Acoustic Amplifier Power and Size

Start by testing smaller amps, with at least 20 watts of power but not more than 75. If you play smaller venues, such as bars, small clubs, etc., and it is just you singing with your guitar and no band, a small amp likely will work just fine. Most players can get away with using a 60-watt amp for smaller venues. And, since the sounds being heard are nothing but the guitar and your voice, there is nobody else to overpower.

Do not be fooled by the smaller size of new acoustic amplifiers. Newer designs can push a lot of sound. They may be lightweight but if it projects the sound well and gets the job done without burning a hole in your wallet, that’s all that matters.

If you find that amps in the 20- to 75-watt range do not project well enough, more power is always available; move up to the 100+ watt models. If that doesn’t work, try the 200-watt models, such as the Fender Acoustic Pro. And if that doesn’t work, you’ll need to plug into a powerful PA at that point.

A Smaller Amp

Fishman Loudbox Mini

The Fishman Loudbox Mini is an example of a great small acoustic amp. It has two speakers: one 6.5-inch woofer and a 1-inch tweeter. It also features dual-channel input to accept both a microphone and an instrument. And the best part is that it’s lightweight. You can carry it around easily, and it’s not a chore to transport and set up. Also, this amp is comparatively affordable.

When inside a building in close quarters, like a small bar or club, the audience sits or stands a whole lot closer to you, the performer, and the sound literally can be bounced off the floor and walls. Outside, things get different very quickly. Even for something as simple as a backyard house party, you will be amazed how quickly the sound goes totally dead when there are no walls around to contain the sound and bounce it back.

A Bigger Amp

Fender Acoustic SFX

For bigger gigs where more volume is required, or for playing outdoors, you need something that can physically move a lot of air and that means a powerful amp with a big cabinet. An example of this is the Fender Acoustic SFX, which is available in a 160-watt version. That’s a lot of power for acoustic projection.

While this specific Fender amp is designed to be lightweight, it’s obviously not nearly as light as the Fishman amplifier mentioned above. Also, as with any larger amp, it’s a more cumbersome box to deal with.

Final Tip

Chances are, you don’t need a huge and ridiculously expensive acoustic amplifier to get a good sound, but you do need something that addresses the circumstances under which you are most likely to use it. Think about where, how and when you are going to use the amp, and buy accordingly.