The Samsung Galaxy S9+ is a great phone. It doesn"t offer a huge leap when compared to the Galaxy S8 but the sum of its parts make it an excellent option for an Android handset. The camera on the Galaxy S9 handsets get a ton of shine but the speakers have also been improved when compared to previous entries.
On the Galaxy S9 and Galaxy S9+, the sound you hear from the handsets have been tuned by AKG and there is also the option of enabling Dolby Atmos to take things to another level. But in order to really take advantage of all of these features, the firm had to make changes to the speaker setup, going from a single speaker and expanding it to two. Samsung states that they wanted to create an experience that would be immersive.
The firm set to work by embedding a dynamic speaker in the top portion of the handset. While this might seem like an easy thing to do, Samsung states that it had to rearrange the internal components near that region, like the front camera and iris sensor, in order to make it possible. On top of this, it had to make sure that the speaker would still sound powerful despite its slim size.
In order to make this possible, the firm utilized engineers from different departments. The team spent a year "modifying the kinetic structure of the speaker to make sure there was enough room", which allowed them to expand the size of the existing speaker by 1.5 times. All of this work allowed the Galaxy S9+ and Galaxy S9 to produce sounds that are much louder than the previous handsets.
Source: Samsung