If your speakers are going to be used outside, they had better be built to withstand the elements they’ll be exposed to. Plus, you want them to look and sound right too. Designing a speaker system to meet all three takes foresight and expertise.
Start by thinking about what your speakers need to do, and where they’ll be located. Will they be part of a drive-thru system, handling mostly voice-level frequencies? An outdoor kiosk, or an alarm system? Will they be playing background music at an outdoor venue or theme park? Will they be at a waterpark and constantly getting wet, or exposed to extreme temperatures in an automotive application?
Picking the right materials for the speaker enclosure comes after making sure the driver (the stuff inside) is engineered correctly to give you the acoustic characteristics you need.
Outdoor speakers systems generally must have the ability to be louder than indoor speaker systems because they have to compete with ambient noise and may be a lot further away from the intended audience. There are two ways you can make a speaker louder. The first way is by increasing the amplifier power into it. That is an expensive solution and could damage a speaker over a long period of time.
Be More Sensitive
A better way to increase volume is to design the speaker to be more sensitive. Sensitivity is a measure of the Sound Pressure Level (SPL), or output, created when power is put into a speaker. SPL is measured in decibels (dB).
A simple way to think about measuring speaker sensitivity is how much SPL, or how many dBs, does a speaker kick out at 1 meter away from it when 1 watt of power is put into it. The only way to change the sensitivity of a speaker is to change the properties and materials (speaker components) that the speaker consists of. Lighter speaker components will make a speaker more sensitive, but could increase production costs or hurt the long-term durability of the speaker. It’s a trade-off that can only be overcome through precise engineering and testing of the speaker components.
There are big advantages to working with a company that can design, test, and manufacture your outdoor speaker system all under one roof the way MISCO does, with state-of-the-art design and measurement tools.
Protection Isn’t a Racket
Once you’ve got the speaker perfected, with precisely the right components, it’s time to protect it against the outside world. That job falls to the grill and the speaker enclosure.
The grill is what covers the face of the speaker, protecting the cone, surround, and dust cap cone. Whatever is in front of the cone will impact the sound in some way. If a speaker is in your house, a light fabric could be all you need to keep dust off of it. For outdoor loudspeakers--where weather, people, and other unpredictable forces come into play--you will likely want either metal or plastic grills. In some situations, you may have two metal grills, each with different hole patterns, over each other to prevent anything from ever touching the speaker, protecting it from vandalism.
There’s a lot of science behind the thickness, hole size, and hole count that goes into designing the grill. It’s important to test a speaker with the grill in-place to ensure you’re getting the sound you want.
Plastic is a good option for the grill material if you’re thinking about a mass-produced product like a Bluetooth outdoor speaker. It can be designed and manufactured to act as a part of the entire enclosure for your speaker system.
Audiophiles have an affinity for wood as the material of choice for a speaker’s enclosure. It has good damping qualities and it is easy to design a wood box that deadens vibrational soundwaves, so you only get the sound coming out of the speaker, instead of the coloration that could otherwise be added by a “live” cabinet material (such as thin metals that can “ring”, adding unintended high frequency content) . For outside conditions, wood may not be a good option, though. Again, metals (such as aluminum or stainless steel) and plastics will do better against Mother Nature.
Want to really dive into the science behind what it takes to make an excellent outdoor loudspeaker? Download the Loudspeaker 101 Guide now.