Expert Answers to Help You Achieve a Flawless Live Sound Experience

Setting up a PA system can seem daunting. You've invested in great gear, but getting it to sound its best involves more than just plugging things in. At NLfx Professional, our team of seasoned audio engineers - who have worked on everything from major concert tours to local community events - gets asked about system setup all the time. In this first edition of our "Ask NLfxperts" series, we're answering some of your most common questions to help you build a solid foundation for a great mix.

Your Top Questions, Answered by the Pros

Q: "Where is the best place to put my main speakers and subwoofers?"

A: Speaker placement is critical for coverage and clarity. For your main speakers (tops), you want them high enough to project over the heads of the front row of the audience, typically on sturdy speaker stands. Place them on either side of the stage, slightly in front of your microphone line to prevent feedback. For subwoofers, the best practice is often to "couple" them by placing them together on the floor in the center of the stage. This prevents weird bass cancellations that can happen when they are spread far apart, resulting in a more powerful and even low-end response throughout the room.

Q: "What is 'gain structure' and why is it so important?"

A: Gain structure is the process of setting the proper audio level for each piece of equipment in your signal chain. Think of it as getting the volume right at every step. The most important step is setting the preamp gain on your mixer for each channel. Have your musician or speaker perform at their average volume, and turn up the channel Gain knob (not the fader) until the signal is strong and healthy - usually in the green/yellow on your meter. Remember to never hit the red "clip" light, because as we say in the industry: redlining is not headlining. You should then repeat this process through every channel and your mixer's main output. A proper gain structure is the single most important thing you can do to ensure a clean, noise-free, and distortion-free mix.

Q: "What's the difference between a crossover and a full-range signal?"

A: A crossover is like a traffic cop for your audio frequencies. It takes the full-range signal from your mixer and splits it, sending only the low frequencies (bass, kick drum) to your subwoofers and the mid and high frequencies (vocals, guitars, cymbals) to your main speakers. This is crucial because it allows each speaker to work more efficiently on the frequencies it was designed to reproduce, resulting in a much clearer and more powerful overall sound. Many modern powered subwoofers, like the RCF SUB 15-AX, have a built-in crossover, making this process simple.

Q: "Do my cables really make that much of a difference?"

A: Absolutely. Your cables are the highway of your entire sound system, and they are the most common point of failure. A low-quality or damaged cable can introduce hum, static, and crackles, or fail completely in the middle of a show. This is why we take it so personally and manufacture our own NLfx Pro Platinum Series Cables. Built in the USA with a 95% braided shield and backed by a lifetime guarantee and warranty, they are engineered to deliver a clean, reliable signal every time. Investing in good cables is investing in peace of mind.

Q: "My room has terrible acoustics. What can I do?"

A: This is a huge challenge for many venues. While portable acoustic panels can help, the most effective solution is a data-driven one. As part of our professional design services, we offer a custom acoustic analysis where we use computer modeling to map your specific room. This allows us to recommend the precise speaker placement and acoustic treatment needed to tame echoes and ensure clear, intelligible sound in every seat. It takes the guesswork out of fixing a difficult space.

Proper PA system setup is a blend of science and art, but getting these fundamentals right will solve the vast majority of common sound issues. By focusing on smart placement, clean gain structure, and reliable connections, you're building the foundation for a truly professional audio experience.

Have a more specific question for our NLfxperts? Contact our team of seasoned audio professionals today for personalized advice on your system!