Fundamentals of Architectural Acoustics

Maximize Your Space

No matter what kind of equipment you’re using, the space they are in determines sound performance more than anything else. The size and shape, levels of absorption and reflection, even the materials used in construction all affect the way sound waves move through a space.

This science of sound is a dense subject, but a few fundamentals can help you understand how sound waves behave, and what parts of your space are helping – and hurting – what you hear.

Frequencies and Waves

Sound is measured in frequencies (Hz), which travels in the form of waves. The higher the frequency, the higher the pitch! Higher pitches (or higher frequencies) have a much shorter wavelength than lower frequencies/pitches. This affects how the sound waves travel, and one of the reasons you can hear lower pitches (bass) at a further distance from the sound source.

It’s important to keep these things in mind when you’re doing acoustic treatment, or just when listening to how a particular room sounds. The larger wave forms of lower pitches cover more distance with each cycle, so the bass in the back of a room may be drastically different than right near a subwoofer or amplifier (for just one example).

Reflection vs. Diffusion

When sound waves hit a surface, they behave in a variety of ways. When they “bounce,” it is typically with either reflection or diffusion. Sound waves reflect when they strike a flat surface and bounce back in the same direction. Because a tiny fraction of the energy is lost, the reflected frequency is quite identical – this leads to overtones and distortion within the nearly identical sound waves, and is the primary reason that large, flat surfaced rooms sound harsh to the ear.

Alternatively, when sound waves strike rounded or uneven surfaces, they are diffused – meaning the are “bounced” in multiple directions. Since they don’t reflect exactly back on themselves, there isn’t interference among the waveforms. This is why you see acoustic treatment with textured surfaces, or why rooms with many angles and objects tend to sound “warmer” or less harsh.

Absorption

Sound waves are also absorbed by the objects they hit. Different materials offer different levels of absorption, and frequencies ranges behave in their own unique waves. Higher frequencies are more easily absorbed, while lower frequencies can pass through objects. This means that lower frequencies often far more difficult to control. Absorbent materials, like foam, sound absorbing panels, etc. certainly help, but those large waves have to go so somewhere!

There are sophisticated devices and calculations for determining materials absorb what frequencies, and all of these come into play when designing a room with acoustics in mind – or simply adding treatments to a space to improve acoustic properties.

More Resources

In fact, the science of sound is far more than high and low pitches, or what direction your speakers are pointing. It’s math and physics, vibrations in the air moving at incredible speeds and behaving in fascinating, complex ways. For many audio engineers, getting a handle on the basics of acoustics – especially within rooms – is important to mastering their equipment. For architectural acoustic designers, it’s an entire world of study… And for physicists, it’s even deeper!

For a deeper long (and much of the math) explore these resources:

Technicon Acoustics – Acoustics 101
Basic Guide to Architectural Acoustics
USG – Understanding Acoustics in Architectural Design

For questions about your space – and how to improve its acoustics, contact Sound Connections Group today!

Live Sound Tips from Sound Connections Group - SCGAV.com

Tips for Live Sound

5 Top Tips

Mastering the art of live sound engineering is no small undertaking. Every room and every system is unique. There’s a laundry list of terms to memorize and different functions to get familiar with…

That said, there are some basic principles that can go a long way with any mix. You’ll learn as you go, picking up tips and tricks and developing your own workflow. These basic ideas can help you go from a meat and potatoes approach to something a little more nuanced. As you learn and grow, you’ll find more and more uses for effects and the features of your console, but these starting points will help set you on the right path!

Go Easy on The Reverb

Reverb is a great way to add body to vocals and help them stand out – but too much gets problematic (to say the least). If you’re cranking up the reverb, not only will lyrics lose some of their definition, you also run the risk of feedback.

Start small, and gradually increase reverb to add color. Go easy at first and bring it up to a subtle, almost unnoticeable level. A little bit goes a long way!

Subtractive Mixing

Boosting frequencies isn’t the only way to EQ your overall mix! Many novice engineers make the mistake of only bringing up frequencies, maxing things out until there’s no more headroom. If everything is boosted – nothing is!

Instead, try a subtractive approach, pulling frequencies away from channels to bring others out. It may take a little while to get the hang of, but this method leaves you more “wiggle room” to adjust as songs change, and stops you from cranking everything to 11!

Gates for Toms

If you’re putting mics on toms (which may only sometimes be necessary), it’s generally a good idea to use gates to set a threshold of sustain. Toms can be boomy to begin with, and when they’re coming through the PA, a long, sustained pitch can muddy up the rest of the mix – and just sound bad to listeners.

Use gates to keep the tom sound relatively short. Let the attack and tone come through, but shut it down after a clear pitch has been pronounced. Again, you’ll find the right threshold for the room you’re working in with some experience, and develop some rules of thumb that work with your workflow. Regardless of where you decide to set your gates, they’re a good idea to use whenever you’re amplifying a drum set’s toms!

Mute Your Channels!

This is live sound 101. When the set is over, MUTE THE CHANNELS. This should be the very first thing you do when a band or artist is finished playing. If you hit those mute buttons right away, there’s no chance for that awful popping sound as a performer unplugs a guitar. You won’t hear chatter through the vocal mics either.

There isn’t much more to it than that. Muting your channels at the end of a set is critical. Do it every time.

Plan for The Worst

Like any other job, things can go wrong. Batteries in wireless mics can die, DI boxes can fail, cables can go bad… So plan for the worst! Have extras on hand if you can, and put a backup plan in place should things go terribly wrong. Particularly for vocalists, it’s not a bad idea to have another mic ready to go at the side of the stage.

If you can anticipate it, plan for it! Know the pieces of the system you’re working with, and have as many contingencies in place as possible. You won’t be able to repair every problem on the fly, but the more prepared you can be, the better.

This is just a small slice of all there is to know. Experience and study will be your best friends as you learn the ropes of live sound. Always start simple and work toward complexity. If you’d like deeper training on mixing live, contact Sound Connections Group today!

FAQ for audio video systems in Grand Rapids MI - SCGAV.com

How to Select the Right A/V Consultant

4 Main Points

Not all A/V companies are created equal. Deciding that you need an expert to help you design and install an A/V system is just the first step, and finding the right consultant can be a challenge all its own.

There are plenty of things to consider here, but a four central points will make a big difference.

If you look at these categories first, you’re more likely to get the right setup, the right price, and a positive, friendly experience. Regardless of your budget or the scope of your needs, ask questions of any company or consultant you speak with, and do you best to find reviews that cover these important topics.

Experience

First and foremost, you need an A/V consultant that knows what they’re doing. It’s critical to look for a company that has been in business for a while (or at least employing veteran engineers), and staff with a wide range of experience.

A well established business or individual, with a diverse, successful portfolio of work, is going to be more trustworthy. They won’t cut corners or overlook details, and they’re more likely be able to recommend the right equipment for your needs.

Equipment Choices

A great system starts with great gear. You may be able to find cheap quotes, but are they using subpar brands? The lowest prices may be tempting at first, but if your consultant isn’t using professional quality equipment, you’ll end up paying more in the long run on repairs and replacements.

There’s a happy medium to be found, where you’re getting reliable equipment that fits into your budget. Make sure you choose a consultant that uses quality A/V gear across the available price points – including cables, microphones, and other accessories that some companies may skimp on.

Most consultants will list their preferred brands, and a quick internet search will let you know if they are recognized across the industry, or if they are cheap alternatives that should be avoided.

Training

A hugely overlooked necessity in the world of A/V consulting and installation, training means knowing how to actually use the equipment you buy. If a consultant you’re considering has programs to show you and your team the basics (or more advanced concepts), you’re well on your way to getting the most out of your A/V installation.

Even if it’s simple tips and tricks for the most basic setup, feeling comfortable with your equipement goes a long way in creating a worthwhile experience. What good is the best system in the world if no one in your building knows how to operate it?

Customer Service

A/V work tends to be very complex, with dense terminology and hard to remember abbreviations – so it’s easy for technicians and consultants to lose sight of their customers and focus only on the technical details. The best consultants, however, bridge the gap between industry jargon and the people who need their help.

For a friendly, informative experience, look for companies with a strong track record of customer service. These types of businesses will lead you through the often confusing process, answering questions and putting things into the simplest possible terms.

Lack of personable service is a common complaint in this industry, so take great care to find a consultant focused on you and your needs, not just the equipment.

Choose with Confidence!

With these things in mind, you can weigh your options with confidence. You may have other concerns or special needs, but the basic criteria above will apply to any and all A/V projects. Don’t hesitate to reach out by phone or email to discuss your requirements – a consultant worth hiring will be more than happy to answer your questions.

If you aren’t sure what you need, or even where to start, contact Sound Connections Group to start the conversation!

 

Audio Video Tips for Churches

See & Hear Better!

For your congregation to get the most out of the service they’re attending, they need to see and hear with clarity. Musical nuances can be lost because of a bad mix. The most powerful parts of a sermon can go unnoticed if people are distracted by harsh lighting or a clipping microphone.

Problems with light and sound pull your congregation out of the experience, so knowing how to resolve them – or prevent issues from happening in the first place – becomes not just a technical issue, but a spiritual one as well!

There’s no way to fully foresee every lighting or audio scenario, but these tips can help you anticipate the events of a service, and use your A/V equipment to make them look and sound their best.

Front Lighting vs. Backlighting

The placement of your lights (and when you decide to use them) can have a significant effect on how people perceive what’s happening. Front lighting is used to give clarity to the audience, illuminating the people on stage and creating points of focus for the congregation.

Alternatively, backlighting gives depth, helps create mood, and adds contrast between the elements in view.

Understand the difference between these two light sources, and how they affect how the rest of the room sees the service. Think about when a speaker needs to be lit from the front to draw attention, or when a band may need heavier backlighting to set the mood.

2. Consider Presets

If you’re using a digital mixing board, you likely have the ability to save presets. This is especially useful if the worship band is using the same instrumentation for every service. Consider creating and storing a preset for the typical band, or even for other parts of service (like a choir, certain speakers, etc.).

This will give you baseline to start from, and make mixing a matter of fine tuning – instead of starting from scratch every time.

3. Minimize Microphone Bleed

Pay close attention to the levels of each microphone on stage, and consider what other ambient sounds they might be picking up. Too much unintended sound in a microphone can be disastrous, so it’s critical to pay attention to both placement and EQ – especially with vocal mics.

If your singers are too close to the drummer or a guitar amp, the high frequencies can bleed into the vocal mics. This can lead to feedback, muddy vocals, and an overall harsh mix in your vocal channels. Do your best to position your vocal mics strategically, and use EQ to highlight the singer’s frequency (and mix out harsh cymbal sounds).

This is just the beginning of all there is to keeping your church service looking and sounding its best. These tips can get you started, but the ins and outs of a great A/V is an entire universe of details to learn. Experiment, be patient, and always be conscious of what’s facilitating the overall service.

If you have questions, or are looking to expand your training, contact Sound Connections Group today!

Why Use High Pass Filters?

HPF & Vocals

Using a HPF properly can be one of the best things you can do for your vocal mix.

One of the most common things we encounter at events that have live audio is excessive amounts of bass where it shouldn’t be.

This leads to wind noise, popping and low intelligibility. Specifically with vocals, but in other areas as well.

Most mixers, even on some of the less expensive models have some kind of a low frequency roll off or a high pass filter (HPF) switch. More sophisticated analog and all digital mixers have a variable frequency high pass filter.

What is a HPF and why and where would it be utilized?

The HPF is a very simple tool that “filters” out a range of frequencies below a selected frequency.

The most common HPF frequencies are 75 Hz and 100 Hz for fixed filters. Variable can be from 20 to 20,000 Hz on some higher end analog and most digital consoles.

The switch location is generally next to the input gain adjust on analog consoles and in various locations on digital consoles.

When should it be used?

We use it on every vocal channel and set it between 150 Hz to 300 Hz as a starting point. The human voice is very complex so there is no magical setting that works on everyone equally.

Why is it used?

For vocals there is little to no useful information below 100 Hz

 

For more information, and expert A/V services in West Michigan, contact us today!