Samsung will reportedly soon employ its own audiocasting screen technology called "Sound on Display," either on the Galaxy Note 10
or the Galaxy S11, to shave off the top bezel even further compared to what's on, say, the Galaxy S10+
(which is not much to begin with.)
The initial rumor was that it will appear in the Note 10 but looking at the leaked press renders
, it does have a small earpiece/speaker slit in the top bezel still, so a soundcasting screen may be saved for a grand Galaxy S11
LG has a similar tech called Crystal Sound that it has already pioneeringly employed on the LG G8, Sony's had its Acoustic Surface for a while on TVs, too, and Huawei just employed its Acoustic Display Technology on the P30 Pro
In fact, as early as last year's MWC expo in February, we were able to play around with the Vivo APEX concept that then turned into the Vivo NEX
retail phone, and, while its signature feature at the time was the finger scanning that worked over half of the display, the Screen SoundCasting technology was already present as well.
Here it is on the retail NEX
, in the from of a small actuator glued to the back of the OLED panel, sending its electromagnetic impulses directly to the panel which ripples the air above it to deliver the sound vibrations to your eardrum.
The Vivo NEX Screen SoundCasting actuator makes the top of the screen vibrate and emit sound"
What's Sound on Display?
An interesting sound-emitting display concept by Samsung got our attention when showcased at the Society of Information Displays (SID) expo last year. As you can see in the video above, the Samsung rep explains how a panel using vibration and bone conduction may negate the need for an earpiece, helping extend the screen all the way from top to bottom.
They had a "Sound on Display" tech prototype at hand, running in what seems to be a Galaxy S9+
casing, and the presenter joked that we are actually looking at the Galaxy S10
display here. That never happened, but we keep our hopes high for the S11.
Galaxy A60 already has the screen speaker tech
Both Samsung and LG already commercialized their sound-emitting OLED displays in phones, the G8 and Galaxy A60.
The transmission bandwidth is said to be in the 100 ~ 8000 Hz range, and, thanks to the very fine vibrations, you would only hear the sound if you put your ear to a fairly wide area at the top half of the screen, denoted with a circular symbol here.
According to Vivo, "compared to other audio solutions for bezel-less smartphones, it conserves power, reduces sound leakage, and optimizes low to high pitch sound for a better and more balanced audio experience." Here's what the Crystal Sound exciter looks like inside the LG G8:
How does Sound on Display work?
First off, you need an OLED display to place small exciters/actuarors behind. The LCD panels have an extra backlight layer that can't transfer the tiny electromagnetic vibrations that the exciter pumps through the screens, using the top layers as a speaker diaphragm of sorts.
When we talk about speakers, you are probably imagining those cone-shaped diaphragms that sit atop a magnetic gap between them and the voice coils. Diaphargms needn't be cone-shaped, though, the sheer nature of vibrations produces enough of an air ripple effect to emit sounds, and that's exactly what those tiny actuators behind the displays of the G8 or P30 Pro
are meant to do.
Pro actually has two circular ones looking like watch batteries - the larger ones to emit the conversation from the top of the screen where an earpiece would be, and the smaller one to vibrate for notifications and such, a pretty clever setup.
Samsung's own Sound on Display technology works in a similar fashion - a tiny actuator or two behind the AMOLED displays. The humble Galaxy A60/M40 are the ones where this Samsung technology employed first, and this, coupled with their punch-hole display designs makes them achieve an "all-screen" front similar to its much more expensive brethren in the Galaxy family. They use just one tiny exciter behind the AMOLED display, as you can see in the screenshot from the disassembly video below.
Samsung, however, doesn't advertise this as Sound on Display, but just says Screen Sound Technology, and with a good reason. They do have speakers inside, and the tiny screen exciter motors make the top of the display vibrate only during voice calls, as you can see in the disclaimer below. Whether or not this will be the case on the upcoming Galaxy Note 10, remains to be seen.