1.6 Sound reflections
In the market of consumer electronic s for audio products, some designs focus on sound performance and others might focus on ID appearances and prices. A unique ID sometimes limits the position of the loudspeakers. How can we get a balance between the ID appearances and acceptable sound performance? It's always a critical task for designers. Using FEA (Finite Element Analysis) tool to predict and analyze the influences of sound performance when the ID was initially locked down and the optimizing position of loudspeaker can be chosen. Here are three scenarios with different positions of loudspeaker inside a product. The figure 1 shows the loudspeakers’ positions inside the product of the scenario 01.
The two loudspeakers inside the product are in parallel, the z axis is expected toward to the end users. The figures 2 shows the simulation conditions and results of scenario 01.
The simulated and predicted SPL (Sound Pressure Level) and impedance curve of the scenario 01 are showed on the figure 3.
The figure 4 shows the loudspeakers positions inside the product of the scenario 02.
The figure 5 shows simulation conditions and results of scenario 02.
The simulated and predicted SPL (Sound Pressure Level) and impedance curve of the scenario 02 are showed on the figure 6.
The figure 7 shows the loudspeakers' positions inside the product of the scenario 03.
The figure 8 shows simulation conditions and results of scenario 03.
The simulated and predicted SPL (Sound Pressure Level) and impedance curve of the scenario 03 are showed on the figure 9.
The figure 10 shows the comparisons of SPLs and impedances for the three scenarios. The simulated results tell us that the scenario 01 has the highest SPL.
It's easy to understand that there are no impacts on the impedance curves if the loudspeakers' positions are different. But the SPL will be influenced by differently sound fields and reflections. From analyzing the compared results, the scenario 01 has highest SPL from around 1.2 KHz to 10 KHz. Which means that it's the optimize position for the product if the loudness is an important requirement for designing purposes. The scenarios 02 and 03 have almost the same performance if the product's applications don't need to extend the high frequencies over 10KHz. Or the cancellations of sound fields at high frequencies are more serious on scenario 03.