Consistent practice is the best way to improve at the guitar. But here’s the thing: guitars—electric guitars, especially—are loud.
If you live in an apartment with super thin walls, cranking up the volume might result in less-than-pleased neighbors. You certainly don’t want them knocking at your door and complaining about the “noise” in the middle of your jamming session.
The solution? Get yourself a guitar amp isolation box.
Guitar amp isolation boxes, as the name suggests, are large amp-shaped enclosures that prevent excessive sound from leaking into the outside environment. When equipped, you’ll be able to turn up the sound of your guitar amp without risking noise complaints.
This article discusses everything you need to know about guitar amp isolation boxes, including how to build one yourself. Let’s dive right in!
How Do Guitar Amp Isolation Boxes Work?
Guitar amp isolation boxes, also known as iso boxes, are custom-made enclosures designed to keep the noise produced by a guitar amp down.
Although often advertised as such, these boxes aren’t completely soundproof. Single-layer isolation boxes reduce sound but don’t completely cut off the noise produced by the speaker. Double-layered isolation boxes do a better job in dampening the sound but it still leaks audible bass.
If you truly want to silence the noise produced by the amp, the box must be equipped with several layers of MDF, plywood, or a soundproofing board depending on the wattage of the guitar.
Guitar amp isolation boxes work as you expect them to. Instead of plugging in the speaker directly to the guitar, you’ll run the cable out from the amp and into the box.
The basic idea here is to create a sonically insulated enclosure so the outside world can’t hear the “loudness” of your amp. This is why these boxes are ideal for areas that can’t handle much sound like church buildings.
Some people reduce volume leakage even further by adding a power attenuator between the tube power amp and the isolation box. The attenuator reduces the power delivered to the speaker and, subsequently, the volume.
Can You Build Your Own Isolation Box?
Isolation boxes can be purchased from any major instrument retailer. However, some of them are fairly expensive. Plus, they’re often too big and too heavy to move around. Budget-friendly iso boxes are available, but they don’t do that great of a job when keeping the noise down.
Low-effort DIY implementations of this approach do exist. You don’t necessarily need to build a box to dampen the noise produced by your amp. Instead, you can simply put the guitar speaker in a closet or place gobo partitions around the amp to somewhat deflect the noise. You can also cover the amp with several layers of heavy blankets or even use a rolling tour box.
With that said, these methods aren’t often that effective. They’ll reduce the sound but not by a large margin.
If you want to create a workable isolation box, search for a box large enough to fit about two amplifiers and cover the walls with acoustic foam, floor laminate, and two layers of plywood.
If you want to take it a step further, add two layers of soundproofing board such as Wonderboard or Homasote. If you don’t have a box, you might want to build one from scratch or visit a crafts store to build it for you.
Georg Figél made a brilliant step-by-step YouTube guide on building your own isolation box. His technique is by far the most effective I’ve seen.
Tips to Follow When Building an Isolation Box
Building an isolation box from scratch is fairly straightforward. However, there are several tips to to follow throughout the process to effectively create one.
- When making an isolation box, make sure the seal is air-tight for optimal sound isolation. If it isn’t sealed properly, the sound will leak out.
- DIY isolation boxes aren’t suitable for combo amps as they’re susceptible to heat-related problems. The tubes and/or amp head need air to work, which isolation boxes don’t have (unless partially sealed). The lack of air inside the box might significantly damage the amp.
- Be careful when cranking up your amp all the way as it can easily overheat when used inside the box for a prolonged period.
- Volume reduction varies from material to material. The thicker the insolation, the better the sound barrier.
Other Methods to Dampen Guitar Sounds
Apart from the isolation box, there are several other methods to dampen the sound of your guitar.
If you tend to practice the guitar late at night, consider plugging a pair of headphones into the amp or multi-effects pedal. Alternatively, plug the headphones into a mini-amp so you won’t disturb others when playing.
You can also soundproof your room by covering the walls with moving pads, quilts, tapestries, thick blankets, or any other soft material.
Installing sound-absorbing acoustic foam panels to the walls is likewise a great way to reduce the noise coming out of your room while playing the guitar. For the ceiling, hang several acoustical foam “clouds” to eliminate echoes and absorb noises generated by your amp.
If you live with other people, sealing the gap under your door with a rubber weatherstrip works wonders. If you don’t have a weatherstrip, use a thick towel.
Finally, considering adding a soundproof wallpaper made of thick polyethylene foam to dampen the vibrations and sounds coming from your amp.
Final Thoughts
Guitar amp isolation boxes have a number of functions.
For one, they significantly reduce the sound produced by your amplifier, allowing you to practice the guitar without disturbing your neighbor or your roommate.
When used in a recording studio, these boxes prevent the sounds from the guitar from spilling into the microphone or drowning out other instruments. They also prevent unwanted distortion.
Although these boxes are readily available in music stores and online retailers, you can make one yourself with the appropriate tools. Just make sure the box is designed to fit the dimensions of your amp. Good luck!