[iPad Teardown (4)] Question Raised on Speaker Unit

Apr 23, 2010
Nikkei Electronics Teardown Squad
The speaker unit
The speaker unit
[Click to enlarge image]
It transmits sound outside the chassis.
It transmits sound outside the chassis.
[Click to enlarge image]
The long and thin hole
The long and thin hole
[Click to enlarge image]
The disassembled speaker unit
The disassembled speaker unit
[Click to enlarge image]
Is sound transmitted through the entire chassis?
Is sound transmitted through the entire chassis?
[Click to enlarge image]
The disassembled iPad
The disassembled iPad
[Click to enlarge image]

Continued from [iPad Teardown (3)] Heavy Glass Makes Tough Body

After disassembling the iPad and examining its components, we took a break. The excitement and strain that we felt during the disassembly had gone, and we were chatting over tea.

However, I could not help thinking about the speakers of the iPad. Why in the world did Apple place the two speakers side by side? They are so close to each other that they do not seem to have any stereo effect.

In the first place, it is probably difficult for users to experience stereo effect with the iPad, which can be used in various positions. Then, why didn't Apple use just one speaker? Did it use two small speakers to ensure enough sound volume because there is no place for a big speaker? I asked these questions to an engineer.

"Huh? I have no idea," he said.

He did not seem to be interested in speakers, which might have a lower profile than, for example, chips. But I could not give up and asked the same questions to another engineer.

"Year, it's weird," he said.

He took the speaker unit and closely looked at it. It has slots that transmit sound to three holes on the chassis of the iPad. One speaker is connected to two holes while the other is connected to one hole.

"Hey, look at this," the engineer said, pointing at a long and thin hole located at the edge of the unit. "Probably, sound is transmitted to this hole."

Then, he inserted the blade of a cutter knife into the joining area of the unit. The speaker unit split into two parts, and we found a slot that seemingly transmits sound from one speaker.

"I think Apple employed this structure to spread sound in the chassis," the engineer said. "It is difficult to use this structure with a device equipped with a hard disk drive (because sound vibration has adverse effects on HDDs, sometimes increasing their read and write time)."

"That might be true," said an engineer who was operating another iPad that was not disassembled. "With my hands, I can feel that sound is being transmitted through the entire chassis."

I did not know if an answer was given to my original question. But I was kind of satisfied by those findings and wrapped up the teardown.