Help with fixing frequency response on Chinese Android Auto/Carplay unit
Hello everyone,
My first time posting here, I wanted to ask for some help with improving the audio output on an Android Auto/Carplay retrofit unit. It is a specific unit made to integrate into the vehicle and so I'd like to use it over a generic solution.
I notice a lack of low end bass output, around 50hz and lower. A frequency sweep shows this as well. I'm examining the PCB to find an OP-AMP with perhaps a resistor/capacitor/inductor on the output stage that is not the ideal value. I found a Class D IC that appears to be the main output to the cars AUX input. Another forum mentioned swapping out a couple of resistors from 1k to 56 ohms and this improved the top end for their particular issue, I was wondering if this could apply to my PCB as well.
The amp on the back of the PCB:
CS3818EO:
https://datasheet.lcsc.com/lcsc/2004300932_SEMICO-CS3818EO_C523711.pdf
Google translate version:
Google Translate
Any guidance or help would be appreciated.
Front of PCB:
front.jpg - Google Drive
Back of PCB:
back.jpg - Google Drive
Thank you,
Hello everyone,
My first time posting here, I wanted to ask for some help with improving the audio output on an Android Auto/Carplay retrofit unit. It is a specific unit made to integrate into the vehicle and so I'd like to use it over a generic solution.
I notice a lack of low end bass output, around 50hz and lower. A frequency sweep shows this as well. I'm examining the PCB to find an OP-AMP with perhaps a resistor/capacitor/inductor on the output stage that is not the ideal value. I found a Class D IC that appears to be the main output to the cars AUX input. Another forum mentioned swapping out a couple of resistors from 1k to 56 ohms and this improved the top end for their particular issue, I was wondering if this could apply to my PCB as well.
The amp on the back of the PCB:
CS3818EO:
https://datasheet.lcsc.com/lcsc/2004300932_SEMICO-CS3818EO_C523711.pdf
Google translate version:
Google Translate
Any guidance or help would be appreciated.
Front of PCB:
front.jpg - Google Drive
Back of PCB:
back.jpg - Google Drive
Thank you,
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Does it have a line-level subwoofer output? Maybe that's where the bass is going. Add a subwoofer and problem solved. If that's not feasible, then I suspect there would be something resembling an active crossover "upstream" of the power amp chip. But, since it probably doesn't have pots for volume and balance, that might well be happening inside whatever chip handles audio output and volume controls. Are there any configuration options for bass management?
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