iPhone 7 Plus's matching grilles are for symmetry, not sound

The additional grille on the bottom of the new iPhone 7 Plus is not part of the device's dual speaker system as some initially believed, according to a company known for its teardownsof new smartphones.

When Apple launched the product earlier this month, it bragged of having an iPhone with stereo speakers for the first time, delivering twice the audio output of the iPhone 6s.

With the iPhone 7 and larger Plus model, the headphone jack disappeared, making room for a second row of holes that some reviewers at first thought served as a second speaker. However, those testing the new phones soon started calling it a faux grille, sayingApple only added it for aesthetics.

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Tech reviewer Christian Zibreg wrote on Thursday that "we need to clear up the confusion" about a feature that appeared to be added"purely for cosmetic reasons."

The California-based company iFixit, which issues repair manuals for users, released the results of its teardown for the iPhone 7 Plus in Tokyo, revealing "what's hidden inside" on Friday, the same day the smartphones went on sale.

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"Closer inspection shows a new, second lower speaker grille that leads... nowhere? Interesting," the iFixit review said.

The specialists also said thePlus "bizarrely opens to the side," instead of fromthe top,as in previous models.

A less detailed teardown two days ago showed there wouldn't be roomfor a second speaker close to the grille because Apple decided to use the space for a slightly larger battery andTaptic Engine, which sits under the battery and makes the home button more responsive.

TheiFixitteardown showsthe Plus model has a 2,900 mAh (milliampere hour)battery, which is slightly more than 5 per cent larger than the 2,750 mAh battery used in last year'siPhone6s Plus.

"In place of the headphone jack, we find a component that seems to channel sound from outside the phone into the microphone, or from the Taptic Engine out," the repair experts said.

TheiPhone7 has a similar design with a faux grille that does not open up to a speaker.

The actual second speaker that creates what Apple claims is stereo sound is in the earpiece at the top of the iPhone 7 and 7 Plus.

Apple didn't specify the purpose ofthe second grille on launch day, but itdid release a tiny graphic of a phone showing sound waves coming from opposite ends of the device.