troubleshooting • chapter 5

Avoiding ground loop noise

In today’s studio, where it seems every piece of equipment has its own computer chip inside, there are many opportunities for ground loop problems to occur. These show up as hums, buzzes or sometimes radio reception and can occur if a piece of equipment "sees" two or more different paths to ground. While there are methods to virtually eliminate ground loops and stray radio frequency interference, most of the professional methods are expensive and involve installing a separate power source just for the sound system. Alternatively, here are some helpful hints that professional studio installers use to keep those stray hums and buzzes to a minimum.

￿KEEP ALL ELECTRONICS OF THE SOUND SYSTEM ON THE SAME AC ELECTRICAL CIRCUIT.

Most stray hums and buzzes happen as a result of different parts of the sound system being plugged into outlets of different AC circuits. If any noise generating devices such as air conditioners, refrigerators, neon lights, etc., are already plugged into one of these circuits, you then have a perfect condition for stray buzzes. Since most electronic devices of a sound system don’t require a lot of current (except for power amplifiers), it’s usually safe to run a multi- outlet box or two from a SINGLE wall outlet and plug in all of the components of your system there.

￿KEEP AUDIO WIRING AS FAR AWAY FROM AC WIRING AS POSSIBLE.

Many hums come from audio cabling being too near AC wiring. If a hum occurs, try moving the audio wiring around to see if the hum ceases or diminishes. If it’s not possible to separate the audio and AC wiring in some instances, make sure that the audio wires don’t run parallel to any AC wire (they should only cross at right angles, if possible).

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PEQ-450 Reference Manual

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Alesis PEQ-450 manual Avoiding ground loop noise, Keep Audio Wiring AS FAR Away from AC Wiring AS Possible

PEQ-450 specifications

The Alesis PEQ-450 is a powerful equalizer that caters to both professional sound engineers and audiophiles seeking to enhance the sonic quality of their audio tracks. This innovative piece of equipment incorporates advanced features and technologies that set it apart in the crowded market of audio processing gear.

One of the hallmark features of the Alesis PEQ-450 is its dual-channel 31-band graphic equalizer, allowing users to precisely fine-tune their audio output across a wide frequency spectrum. Each channel operates independently, making it an ideal solution for stereo applications where distinct control over left and right channels is essential. The equalizer covers a frequency range from 20 Hz to 20 kHz, ensuring that both low-end and high-end frequencies are addressed, thus delivering a rich and balanced audio experience.

Another notable characteristic of the PEQ-450 is its user-friendly interface, featuring an intuitive layout of sliders that clearly indicate gain adjustments per frequency band. The visual representation of frequency bands allows sound engineers to make quick and effective adjustments in live sound environments, where precision is paramount. Additionally, the unit includes bypass switches for each channel, enabling users to easily compare adjusted sound with the original signal.

In terms of technology, the Alesis PEQ-450 employs high-quality components that contribute to a low-noise operation and a high signal-to-noise ratio, ensuring that your audio remains pristine. The unit also includes a built-in limiter for each channel, protecting against signal clipping and distortion, which is crucial when working with loud audio sources.

The rack-mountable design of the PEQ-450 enhances its usability in studio and live settings alike, making it a versatile tool for audio professionals. The durable construction ensures reliability even in demanding environments, while its lightweight nature adds to its portability.

For connectivity, the Alesis PEQ-450 supports both balanced XLR and TRS inputs and outputs, making it compatible with a wide range of audio equipment. This flexibility allows for easy integration into existing setups, whether it be for live performances, broadcasting, or studio recordings.

In summary, the Alesis PEQ-450 is a feature-rich and technologically advanced equalizer that stands out for its precision, ease of use, and versatility. Whether you are an experienced engineer or a new enthusiast, the PEQ-450 offers the tools needed to achieve exceptional sound quality.