The Ultimate Guide to Guitar Feedback: Mastering the Art of Controlled Screams

Guitar feedback, that glorious, sustained howl, that infinite note that seems to defy the laws of physics – it’s a sound that’s captivated guitarists for generations. From the soaring leads of Hendrix to the grunge-fueled riffs of Cobain, feedback has been a crucial element in shaping some of the most iconic guitar tones in history. But it’s not just about cranking up the volume and hoping for the best. Mastering feedback is an art form, requiring a delicate balance of technique, gear, and understanding of the underlying principles. This comprehensive guide will walk you through the intricacies of creating, controlling, and ultimately, harnessing the power of guitar feedback.

Understanding the Physics of Feedback

Before diving into the how-to, let’s understand the why. Guitar feedback, in its simplest form, is a self-sustaining loop. The sound from your guitar’s strings is amplified by your amplifier, and then a portion of that amplified sound travels back to your guitar and causes the strings to vibrate further. This creates a positive feedback loop, where the sound continuously increases in amplitude until it reaches a point of stability or runaway. It’s like holding a microphone too close to a speaker – that ear-splitting squeal is uncontrolled feedback. The challenge for guitarists is to tame this beast and use it creatively.

Here are the key elements involved in creating guitar feedback:

• Sound Source: The guitar strings are the initial source of vibration.
• Amplification: The amplifier takes the weak signal from the guitar and makes it louder.
• Air Transmission: The amplified sound travels through the air to the guitar.
• Guitar Vibration: The sound waves cause the guitar body and strings to vibrate.
• Sustain: If the cycle is self-sustaining, the note will continue to resonate.

Essential Gear for Feedback Mastery

While you can technically achieve feedback with almost any guitar and amp setup, having the right gear can make a world of difference in how easily you can generate and control it. Here are some key pieces of equipment to consider:

1. A High-Gain Amplifier

The amplifier is the heart of the feedback system. A high-gain amplifier, particularly a tube amp, is ideal. These amps have the natural compression and harmonic richness that contribute to creating thick, controllable feedback. Look for amps with a dedicated gain or overdrive channel. Solid-state amps can produce feedback, but they may sound less organic and responsive. Models like Marshall JCM800, Mesa/Boogie Dual Rectifier, or Orange Rockerverb are popular choices for their excellent feedback characteristics. When dialing in your amp, start with a good amount of gain, but not so much that it’s constantly feeding back. This way you can control the feedback more precisely.

2. A Guitar with Humbucker Pickups

Humbucker pickups, with their higher output and thicker tone, are generally better at producing feedback than single-coil pickups. They’re more sensitive to the vibrations coming from the amp and tend to generate a richer, more sustained sound. Gibson Les Pauls, SGs, and many other guitars feature humbuckers and are favorites of many players who rely on feedback. Single-coil pickups, often found in Fender Stratocasters and Telecasters, can also produce feedback, but they require more volume and gain. It’s not impossible but will require a bit more effort to get it started.

3. Volume Pedals and Overdrive/Distortion Pedals

While not strictly necessary, volume pedals can be very useful for controlling the intensity of your feedback. By rolling back the volume before feedback takes off, you can create smooth transitions and prevent squeals. Overdrive and distortion pedals can be used to boost the gain even further, making it easier to initiate feedback at lower volumes. Popular pedals such as Ibanez Tube Screamer or BOSS SD-1 can help a lot in this regard. Experiment with different combinations of pedals to find your desired feedback tone.

4. Guitar Choice

The construction of your guitar also plays a role in how easily it feeds back. Guitars with solid bodies tend to be more prone to feedback, while semi-hollow or hollow body guitars are more susceptible to uncontrolled feedback. Additionally, the wood type, neck construction, and the density of your guitar can all affect the nature and ease of generating feedback. Experimenting with various guitars can yield a variety of results. Often, slightly lighter guitars with good sustain properties will be easier to coax into feedback.

Step-by-Step Guide to Creating Controlled Feedback

Now that we’ve covered the basics, let’s get into the nitty-gritty of creating feedback. Here’s a step-by-step guide to help you get started:

Step 1: Dial in Your Amp Settings

Start with a fairly high gain setting on your amplifier. You want enough distortion to provide a good foundation for feedback, but not so much that it’s constant, uncontrollable chaos. Experiment with different gain levels until you find a point where you can just barely hear the initial stages of feedback while playing a note. Keep the master volume at a reasonable level to avoid excessive loudness, particularly when practicing at home or in small spaces. The goal here is to find your “sweet spot”, where the amp is set up to give you feedback with a bit of work but not feeding back constantly on its own.

Step 2: Position Yourself Relative to Your Amp

The physical distance and angle between you and your amp are critical. Experiment with standing different distances from your amplifier and see how it affects the feedback. Begin by positioning yourself so the sound waves of your amp can effectively cause your guitar to vibrate. A good starting point is to stand about three to six feet away from your amp and angled slightly towards it. The perfect position will depend on your amp, your guitar, the room acoustics, and your desired effect. Over time, you’ll learn how to use your body position to manipulate feedback.

Step 3: Find the Sweet Spot and Initial Sustain

With your amp set, guitar in hand, and positioned correctly relative to your amplifier, you are now ready to get into feedback generation. First, select a note or chord that you want to sustain. Using your hand to dampen the strings except for the note you want to sustain will help. Now, strike the note with enough force for it to be audible and let it resonate. As the note decays, listen carefully for the characteristic beginning of feedback as you get closer to the sweet spot. Experiment by slightly moving around, you are trying to find that sweet spot where the sound begins to feed back on itself.

Step 4: Manipulate Feedback through Movement

Once you’ve achieved initial feedback, use micro-movements to control its intensity and pitch. Small changes in your position relative to the amp can significantly affect the feedback tone. For instance, moving closer to the amp will usually increase the intensity of the feedback, whereas moving farther away can cause it to die away. Tilting your guitar or angling it towards the speaker can also be an effective way to manipulate the sound. As you learn, you can also use the guitar’s tone knob to change the frequencies feeding back, or even bend strings to shift the feedback pitch.

Step 5: Experiment with Different Frequencies and Harmonics

Feedback isn’t just about a single sustained note. You can also use it to create interesting harmonic overtones. By carefully selecting the initial note and manipulating the feedback, you can evoke harmonics that are above the fundamental pitch you are playing. This can create very powerful sounds and is an essential element in achieving the kinds of feedback used by many legendary guitarists. Experiment with different fretted notes and vibrato, and you’ll begin to discover how the feedback responds in different ways.

Step 6: Control the Feedback with Volume

Using a volume pedal or your guitar’s volume knob is crucial for keeping your feedback under control and incorporating it dynamically into your playing. You can use your volume knob to quickly and smoothly transition from a normal note into a feedback note or vice versa. This allows you to use feedback more as a tool, rather than having it on all the time.

Step 7: Embrace Your Unique Feedback Tone

Feedback is a very organic and personal thing. Every guitar, amp, room, and even your playing style will affect the quality and response of your feedback. Instead of trying to replicate someone else’s sound, strive to develop your own feedback style. Use your ear and your knowledge of how the instrument reacts to find the feedback tones you want and develop ways to utilize these within your own style.

Tips and Tricks for Feedback Mastery

Here are some additional tips and tricks to further refine your feedback technique:

• Practice in Different Rooms: The acoustics of your room will drastically affect your feedback. Experiment with different spaces to learn how the environment interacts with your sound. Smaller, more reflective rooms will typically create feedback with less effort.
• Use a Sustainer: For players who struggle to maintain feedback at low volumes, a sustainer pedal or a guitar with a built-in sustainer can help. These devices use electro-magnetic induction to vibrate the strings constantly, which makes generating feedback much easier.
• Feedback at Lower Volumes: You can achieve feedback at lower volumes by using a combination of gain pedals, compression, and an isolation box for your amplifier. This allows you to practice and record in environments that are sound-sensitive.
• Experiment with Different Picks: The type of pick you use can affect the feel and sound of your feedback. Try using different thicknesses and materials to find what works best for you.
• Practice Patience and Persistence: Feedback can be tricky to master, and it will likely take time. Be patient, persistent, and don’t be afraid to experiment. The more you practice, the better you will get at manipulating it.
• Listen Closely: The most important skill is learning to listen. Pay careful attention to how your gear reacts and develop an intuitive feel for where your feedback sweet spot is.
• Use Effects to Alter Feedback: You can further enhance your feedback by introducing effects such as delay, reverb, chorus, or flange. These can add a unique dimension to your sound. Experiment with your signal chain to find the effects that make your feedback sound interesting.
• Learn the Relationship Between Frequencies and Feedback: Understanding how different frequencies react to feedback is critical. Higher frequencies tend to be more prone to squealing, while lower frequencies usually produce a warmer, more sustained sound. Use your tone controls to experiment with this.
• Record Your Experiments: Recording your practice sessions is a great way to track your progress and find new and interesting feedback tones that you can then integrate into your playing style. You can analyze your recording for areas to improve.

Conclusion

Guitar feedback is a powerful and expressive tool that can add a new dimension to your playing. With patience, practice, and a good understanding of the underlying principles, you can learn to harness this powerful force and use it to create truly unique and captivating sounds. Don’t be afraid to experiment, be patient, and, most importantly, have fun exploring the endless possibilities that guitar feedback can offer. From the subtle shimmer of harmonic feedback to the controlled chaos of intense, sustaining squeals, the world of guitar feedback is waiting to be explored. Go forth, experiment, and let your guitar scream!