3 Ways to Fix Sound Delay That Are Easier Than You Think
An explanation of what sound delay is, plus 3 recommended ways to fix sound delay at concerts and large-area outdoor events.
A common problem when organizing outdoor concerts or events that use large areas is the large amount of sound reflection caused by the volume of the space. These various points create sound delay, which always causes problems for organizers and listeners. But this problem will be solved, because today we will explain what delay is and recommend ways to fix sound delay as a guide for you. Let's see what they are.
What Causes Delay?
Delay is the lag in the sound we hear. Simply put, suppose we have 2 speakers placed at positions far apart; the first is close to us, and the second is far from us. If we turn on both speakers at the same time, the sound from the speaker close to us will reach us faster than the sound from the second speaker because of the distance. When the sound does not arrive at the same time, it creates a sound reflection problem. This problem is often found at activities that use wide areas, such as various Expos and concerts.
3 Ways to Fix Sound Delay
Using Line Array speakers: These are speakers arranged in a long vertical line. Their sound-wave dispersion pattern is cylindrical, and the sound direction comes out horizontally. They can be placed on the ground and the speakers' angle adjusted to tilt up toward the listeners. Most come with a Digital Signal Processor (DSP) ready to use, such as an Equalizer (frequency adjuster), Crossover (signal level controller), Compressor (frequency separator), Delay (audio delay unit), and Feedback Suppressor. This method uses a relatively high budget, but it is the method that solves the problem most "precisely."
Adding speakers at the points where delay occurs: For anyone who does not have Line Array speakers, as a first step, use medium-sized speakers to help reinforce the points where delay occurs, to help increase the volume and clarity of the main speakers so they cover distant areas. But placing speakers alone is not enough; you must also use an audio delay unit (Delay) to help, so that listeners hear the sound from the delayed speaker and from the main speaker at the same time. This is calculated from the distance between the main speaker and the delayed speaker (in meters) divided by the speed of sound in air, or 331 + (0.6t), where t is the temperature (in degrees Celsius). For example, if the speakers are 50 meters apart and the temperature at that time is 20 degrees Celsius, the delay is calculated as 50 ÷ (331 + (0.6 x 20)) = 0.1457. The resulting delay setting is 0.1457 seconds, or 145.7 ms.
Using an audio delay unit (Delay): A device with this Delay function helps offset the distance between speakers so that the sound travels and arrives together. It is measured in milliseconds (ms). This unit is also useful for more than just delaying the speakers, for example:
- It reduces problems when working in places with sound reflection and echo, such as large meeting rooms and outdoor or indoor grounds.
- It makes adjusting or mixing the sound easier, because the sounds traveling out of the LOW, MID, and HI (low, mid, high) speakers arrive together.
- It reduces the chance of microphone feedback (howling) occurring in the system.
- It helps create good sound dimension with balance whether playing loud or soft.
Although adding speakers and using a delay unit is a method that does not use as high a budget as using Line Array speakers, it takes quite a lot of time to set up and requires an expert to manage and control it for the best results.