The models with KOASON Android screen and small speaker are:
1. All BMW EVO models.
2. Mercedes-Benz NTG5, NTG6.0.
3. Audi：Audi A4 A5 S4 RS5 B8 2009-2016 High version，Audi Q5 2009-2016 High version，Audi A6 2005-2011，Audi Q7 2006-2015，Audi A4 A5 2017-2019，Audi A6 A7 C7 RS6 RS7 S6 S7 2012-2018，Audi Q5 2017-2020，Audi Q3 2013-2019，Audi A1 2010-2018，Audi A3 2014-2020。

Some customers who purchased KOASON or above screen models found that there were small speakers in the accessories. Many people did not understand why the small speakers were added. The following are answers to the questions raised by customers.

BMW EVO：

The multimedia sound of the KOASON BMW EVO Android screen enters the original car host through a USB-AUX audio adapter, so the sound is emitted by the 4 speakers of the car.
When making a call, another channel is switched and directly connected to the original front left speaker. Most EVO models have sound when connected to the front left speaker. However, the sound system of some EVO models is special and does not support our Android system, so we equipped a small speaker to solve this problem.
Because it is difficult to distinguish the unsupported models from the appearance, the EVO screens shipped are changed to be equipped with a small speaker as standard.

KOASON BMW EVO screen sound switching mode:
In Android state: make and answer calls, the sound comes out of the small speaker, and the navigation voice broadcast sound comes out of the original car's 4 speakers.
In the original car state: make and answer calls, navigation voice broadcast sound comes out of the small speaker.

Mercedes-Benz NTG5, NTG6.0：

For KOASON Mercedes-Benz NTG5/NTG6.0 models, Android multimedia sound enters the original car host through the USB-AUX audio adapter, so the sound is emitted by the four speakers of the car.
When making a call, another channel is switched and directly connected to the original front left speaker. If it is an ordinary Harman Kardon audio system, there is no problem. But Burmester audios are special. It does not support our Android system, so we equipped a small speaker to solve this problem.
For Mercedes-Benz NTG5/NTG6.0 models, only those with Burmester audios need to connect the small speaker. Those without Burmester audios do not need to connect. There is a label on the bag of the small speaker: ONLY FOR CAR WITH BURMESTER

You can tell whether your car has Burmester audios by looking at the speaker cover on the car door. The following is a car with Burmester audios.

KOASOM Mercedes-Benz NTG5/NTG6.0 screen sound switching mode:
In Android state: make and answer calls, the sound comes out of the front left speaker (or small speaker), and the navigation voice broadcast sound comes out of the original car's 4 speakers.
In the original car state: make and answer calls, navigation voice broadcast, the sound comes out of the front left speaker (or small speaker).

Audi：

KOASON Audi Android screen, Android sound enters the original car host through the AUX channel, so the Android sound is emitted through the car's 4 speakers.
But when making a call in the original car state, switch to another channel and connect directly to the left front speaker of the original car. The left front speaker of A4 A5 S4 RS5 B8 2009-2016 low-end version and Q5 2009-2016 low-end version supports the Android system, so the Android screen corresponding to these two cars does not need to be equipped with a small speaker.
Except for the above two models, the left front speakers of other Audi models do not support the Android system, so a small speaker must be equipped to solve this problem.

KOASON Audi A4 A5 S4 RS5 B8 2009-2016 Low version and Q5 2009-2016 Low version Sound switching mode:
In Android state: make and answer calls, navigation voice broadcast, the sound comes out of the original car 4 speakers.
In the original car state: make and answer calls, navigation voice broadcast, the sound comes out of the front left speaker.

KOASON other Audi screen sound switching mode:
In Android state, the sound goes through the AUX channel, so make and answer calls, navigation voice broadcast, the sound comes out of the original car 4 speakers.
In the original car state: make and answer calls, navigation voice broadcast, the sound comes out of the small speaker.