FAQ

PA systems have evolved significantly in terms of size, features, and quality. Traditional live musical performance setups often include main speakers flanking the stage, facing the audience, and monitors situated on the floor at the front of the stage, directed towards the performers.

Modern technological advancements, like "powered speakers" and digital electronics, have enabled the creation of high-quality PA systems that are smaller, lighter, and more cost-effective. Choosing the right PA system involves careful consideration of your requirements, budget, and transportation capabilities. Introducing the2Mic into acoustic guitar amplification has led to innovative speaker arrangements on stage, notably 'rear monitoring.'

The typical configuration of 'main speakers to the audience and monitors to the stage' is still prevalent in contemporary performances. In larger venues, a sound engineer stationed in a booth within the audience manages the PA mixer.

Before performances, musicians and the sound engineer conduct a sound check to adjust the tone (EQ) and levels of the stage monitors. However, it's important to note that the acoustics can change significantly between an empty venue and one filled with an audience.

While this setup ensures excellent sound for the audience, the performers on stage often struggle with poor sound quality as the house engineer cannot hear the on-stage monitor sound during the performance. This challenge can hinder the performers' ability to accurately hear their instrument and ensemble.

The good news is, for modern classical, flamenco, and acoustic guitarists, new solutions are emerging to mitigate these on-stage sound quality issues during live performances. These advancements have been facilitated by the extreme feedback resistance of the2Mic and the increasing popularity of modern digital electronics and powered speakers.

In a traditional mains/monitors arrangement, two opposing sound fields exist in the performance venue – one directed towards the audience and the other towards the stage. This opposition can create turbulence leading to sound distortions. While the house engineer can correct distortions from the main speakers, they are largely unaware of what's happening on stage during the performance.

A recent innovation is the wide-dispersal 'tower PA', introduced by Bose and designed specifically for solo performers. The tower disperses sound in a wide arc, positioned behind the performer to serve as both mains and monitors.

The2Mic takes the concept of 'rear monitoring' to new heights of tone quality and feedback rejection. To find out more, check out our section on rear monitoring.

Electronic impedance output signals fall into two categories: high impedance and low impedance. High impedance audio systems became standard in the early days of amplification, with mono phone plugs and jacks remaining the preferred output connectors for most musical instruments, despite high impedance's inherent limitations. Since their introduction in the 1960s, low impedance audio systems have gradually become popular, leading to the emergence of "hybrid audio systems" that mix high and low impedance signals for live PA amplification.

High impedance signals, often referred to as "line level signals," are two-conductor, unbalanced mono signals used by most modern pop music instruments—electric guitars, basses, keyboards, guitar and bass amps, among others. These instruments typically use 1/4” phone plugs and jacks, though other mono connectors like RCA connectors and mini (9/64”) phone plugs may also be employed. High impedance gear uses female jacks for input and output with connecting cables that have male phone plugs on both ends. High impedance signals usually operate in the range of 6,000-12,000 ohms. The length of output cables for high impedance signals should not exceed 30 feet (10 meters) to avoid signal degradation or "line loss". However, high impedance signals are susceptible to external interferences, such as CB radios, fluorescent lights, and radio stations, which can cause distortion and other unwanted effects.

Low impedance signals, also called “mic level signals,” gained popularity with the rise of transistors replacing vacuum tubes in audio and music gear. The benefits of low impedance signals are numerous. For instance, they can be “balanced” by adding a third conductor (B+), which provides a stable, fully-protected signal that can be transmitted over long distances without degradation. Additionally, low impedance systems typically use “XLR” connectors, which are more user-friendly. Devices using low impedance have a male XLR output connector on the musical instrument or microphone that produces the audio signal and a female XLR connector on the devices that receive and process the signal. XLR cables can be extended to any length required without signal strength or tonal quality degradation.

One significant advantage of low impedance gear is the ability to transmit “phantom power” along the B+ conductor to power audio gear that requires a low voltage electric current. Such audio gear includes condenser microphones, active direct boxes, effects devices, and similar equipment.

Despite their advantages, low impedance connectors were initially bulky and cumbersome for musical instruments. Therefore, mono 1/4” phone jacks and plugs have remained the standard output connectors on most musical instruments. More recently, mini-XLR connectors and 1/4” “stereo” phone plugs (TRS - tip-ring- sleeve) jacks and plugs have been used to transmit balanced mic level signals. However, TRS cables aren't as readily available as mono guitar cables.

A common workaround is to connect a short mono output cable from a musical instrument to an inline “power supply” or “direct box” (DI box). This device converts the mono signal into a fully balanced output signal for transmission to the PA mixer, often via an audio snake.

The widespread use of high impedance equipment and mono cables in the music industry originated from the vacuum tube-based radio industry, which was the only electronic transmission format available when electric instruments were first created in the 1930s. The ever-popular “phone plug” was borrowed from the telephone industry, and has proven to be a time-tested favorite for signal transmission. Since the 1970s, there's been a steady shift towards low impedance for audio signal transmission. However, high impedance is still widely used on instruments and on stage before being converted to low impedance through a DI box for transmission to a PA system.

Phantom power is an effective method to power various musical devices. Initially exclusive to large PA mixers, it's increasingly incorporated into modern amplification equipment. At the2Mic, we've chosen phantom power for our latest models, aligning ourselves with the future of amplification.

Utilizing phantom power for live performances on stage is significantly more reliable and efficient than relying on batteries or wall chargers. This is particularly crucial on large stages, where multiple instruments and accessory devices may need low voltage power. Avoiding battery reliance eliminates the risk of an unexpected power outage due to dead or dying batteries, preventing potential chaos.

Moreover, a dying battery can be even more problematic than a dead one. The diminishing voltage can cause issues that are difficult to diagnose. For instance, a condenser mic or other musical gear might seem functional with a dying battery, but the signal strength and tonal quality can deteriorate, causing odd, disruptive sounds in the amplified output. Utilizing phantom power ensures that all devices, including your the2Mic, receive the necessary voltage to operate at peak efficiency, signal strength, and tonal quality.

The conventional standard for phantom power from a PA mixer is 48v. However, this voltage is typically "stepped down" by the instrument or accessory to a lower operating voltage (9-24v). The usual operating voltage for condenser microphones, including those used with the2Mic, is 9v.

Several the2Mic models employ an external power supply (EPS-2) to facilitate this stepped-down operating voltage. The EPS-2 can operate efficiently with any 9-48v phantom power source.

The2Mic-EndPin remains the only current the2Mic model powered by a battery. This is due to its unique line-level signal in a "plug 'n play" format, which closely mirrors the performance style of a pickup. As such, the2Mic-EndPin is compatible with various electric guitar effects devices.

Feedback, scientifically described as a "self-generating energy loop," can grow and potentially overwhelm the energy source that initiated the feedback loop's frequency. Guitar transducers, such as electric guitar pickups, are highly resistant to feedback but fail to accurately reproduce natural acoustic tone. On the other hand, microphones are excellent for recording natural acoustic tones but can be prone to feedback. The2Mic uses a patented method of arranging two individual mics into a "phased array," cancelling out feedback in most live performance settings.

Everyone is familiar with the discomfort of high-frequency feedback, and some might recall Jimi Hendrix leveraging feedback as part of his live performance soundscape. These examples illustrate the two extremes of feedback and offer insights into managing and preventing it.

Any amplified sound source can potentially cause feedback, particularly when using one of the three basic music industry transducer types, listed below from greatest to least feedback-prone:

1. Microphones

2. Contact and under-saddle pickups (piezo)

3. Magnetic pickups

Microphones, which detect air movement (air pressure waves), are the most sensitive to feedback but also the most effective at reproducing natural acoustic instrument sounds and the human voice. Microphones capture natural acoustic overtones, which may inadvertently trigger feedback loops. Stringed instruments, which are particularly rich in overtones, are especially susceptible to feedback issues even at modest volume levels.

Contact and under-saddle transducers (piezo pickups) create a signal by detecting vibrations from a guitar's saddle or soundboard. Though less sensitive to overtones than microphones, they can still cause significant feedback problems. Despite variations in models and designs, it is generally agreed that contact transducers don't match microphones in producing a "natural guitar tone."

Magnetic pickups, being the least feedback-prone but also least natural-sounding transducer, capture few overtones. Their simple electronic signals can be easily manipulated, leading to a plethora of "effects devices" for electric guitars. While these devices produce a wide range of sound effects, they are rarely considered "natural" or "acoustic."

Close analysis of Jimi Hendrix's controlled feedback technique provides key insights into how the2Mic controls feedback. Hendrix moved his guitar in circular patterns while also moving towards and away from the speaker. These movements created two independent phased patterns of reception, giving him control over the feedback. Similarly, the2Mic's two individual mics create a phased array receiving slightly different sound pressures, which combine with a phased time delay.

The2Mic is designed to offer the most feedback resistance at higher frequencies, which are typically the most rapidly rising and potentially painful to the ear. When feedback does occur with the2Mic, it is usually in the low to mid frequencies, allowing time for an EQ adjustment and posing only a minor, infrequent nuisance.

Ken Donnell, the inventor of the2Mic, has spent over 30 years perfecting the design of its "phased array." He refers to his work as a "holy grail quest" to create a near feedback-proof microphone capable of reproducing a great natural acoustic tone. He eagerly anticipates the newest generation of the2Mics being used and enjoyed by musicians and audiences alike.

Traditionally, a guitarist playing in a professional setting would depend on an in-house sound engineer, using microphones and floor-mounted monitors, to capture and amplify the acoustic sound of classical or flamenco guitars. However, this arrangement often proves problematic as the engineer, stationed at the sound booth in the middle of the venue, doesn't accurately perceive the sound mix on stage during the performance. The onstage mix can dramatically change between the soundcheck and performance, particularly when the audience fills the room, leaving the guitarist in an acoustical void. The feedback resistance of the2Mic presents innovative possibilities for monitor use (rear monitoring), enabling guitarists to form and manage an onstage "sound bubble." This sound bubble provides the guitarist greater control over their live sound, particularly when performing within an ensemble.

The2Mic, paired with modern digital amplification equipment, can reach impressively high volume levels while preserving natural acoustic tone. This simplified amplification process enhances the auditory experience for both the audience and the guitarist.

The distinctive phased arrangement of the2Mic allows analog miniature mics to precisely capture the tone of an acoustic or classical guitar. Simultaneously, it produces an incredibly dense signal that flawlessly integrates with the digital format of modern amplification gear. The end result? Classical and acoustic guitarists can perform at very high volume levels without feedback, while maintaining natural acoustic tones using small, lightweight powered speakers. This combination offers an astonishing amplified sound experience, both on-stage and for the audience.

The superb tone quality and feedback resistance of the2Mic is challenging and reshaping many established norms for live sound amplification of classical and acoustic guitars. Therefore, it's crucial for guitarists to understand how modern digital amplification equipment synergizes with the2Mic and how they can best leverage this potent combination of analog and digital technologies.

**Rear Monitoring:**

Stage monitors are typically placed on the stage floor in front of the performers, allowing them to hear themselves on a large stage while facing away from the audience. With the2Mic, however, these monitors can be placed behind the performer, facing towards the audience. This configuration generates a unified sound field, with all amplified sound traveling in one direction. Consequently, the performer, audience, and sound engineer all experience this consolidated wave of sound energy.

Unfortunately, traditional handheld or stand-mounted mics cannot be rear monitored due to potential feedback. We aspire to develop a handheld mic with the feedback rejection characteristics of our current the2Mic models in the future, but this remains a distant goal.

Traditional analog recording technologies generate a complex and delicate electronic signal that faithfully captures the natural acoustic tone of a guitar. However, they fall short when it comes to recording a guitarist performing with an ensemble or amplifying the performance to larger audiences. On the other hand, digital technologies produce a simple and dense electronic signal that can be effortlessly processed to attain astounding acoustic tones. This format can be easily amplified for audiences of virtually any size, in any venue, and with any type of musical ensemble. The2Mic represents the ideal fusion of analog technology (electret condenser microphones) and digital technology. It generates an electronic signal that accurately records the subtle details of a guitar's tone, but with a signal density that aligns seamlessly with modern digital technologies.

It's the ability of contemporary digital amplification to process such vast quantities of recorded data that allows the digital realm to craft a sound quality best characterized as "super natural."

Aged analog equipment is adept at capturing the subtle nuances of tone quality, but the delicacy of the electronic signal inherently limits the amplification range of these analog signals. Analog devices tend to be complicated to operate, and the equipment is often bulky and heavy. Moreover, there's a limit to how much an acoustic signal can be amplified before the tone quality starts to degrade.

In contrast, modern digital amplification equipment is much simpler to use, more compact, and lightweight. It's also significantly less expensive, appreciates the incredibly dense signals captured by the2Mic, and can be amplified to extraordinarily high volume levels while still preserving the accuracy of the acoustic tone. By using a the2Mic with modern digital amplification, a classical or acoustic guitarist can now play as loudly as any instrument or ensemble, no matter how large, and still maintain a genuine acoustic sound.