What Causes Loudspeaker Hum and Hiss and How to eliminate it

If you are familiar attending any type of live show, concert or performance using PA loudspeakers, you will most likely also agree that loudspeakers’ humming, hissing or buzzing noise can quickly ruin a performance. This article reviews each of the common causes of audible (and irritating) loudspeakers’ hum and hiss, and discusses effective strategies to … Read More

Understanding Closed, Vented and Band-pass Subwoofer Designs

The history of the subwoofer is inextricably linked with the evolution of the full-range loudspeaker. In the mid-1950s, various manufacturers of hi-fi loudspeakers began to introduce compact, closed-box enclosures that featured long-throw woofers, and in the early 1970s a talented engineer working at Jensen, named James Novak, developed the equations describing a bass reflex (or … Read More

What is Auto Mixing on a Digital Mixer?

An auto mixer, or automatic microphone mixer, is a live sound-mixing tool that automatically reduces the volume level of a microphone’s audio signal when it is not used. This is particularly valuable when several microphones are open at the same time, reducing extraneous noise. In this article, we will describe how the Auto Mixer function … Read More

Practical Tips on Loudspeaker Placement for Live Sound (Part IV)

Perhaps even more important than horizontal coverage is vertical coverage, where elevation and distance become critical. A large part of proper loudspeaker coverage is finding a balance between loudspeaker distance and volume. To a certain extent, having loudspeakers farther from the audience makes it easier to achieve consistent coverage, assuming you have sufficiently powerful loudspeakers … Read More

Practical Tips on Loudspeaker Placement for Live Sound (Part I)

QSC loudspeakers are well-known to provide high-performance, accurate reproduction of audio sources in a wide range of applications. However, unlike a controlled studio environment, the real world provides myriad challenges to achieving sonically-pleasing results with QSC or any other loudspeaker. The conditions created by room shapes, ceiling heights, the presence of acoustically reflective or absorptive … Read More

QSC Directivity Matched Transition technology explained

In the history of professional audio, the introduction of QSC Directivity Matched Transition® (DMT™) technology has been one of those ‘lightbulb moment’ innovations that forever changed how audiences experience sound. In order to fully grasp its benefits, and why DMT is foundational to QSC loudspeaker design, let’s start with some fundamentals of the physics of … Read More

What are the differences between passive, active and powered loudspeakers?

Whether you’re listening to live music in a club, to a film soundtrack at the movie theater, or enjoying some tunes while wearing headphones, the sound you’re listening to is reproduced by loudspeakers. Everyone understands that. Now, designing loudspeakers, which produce sounds that are accurate and enjoyable, can be done in a few different ways. … Read More