If you have a factory amp your current radio puts out a constant high speaker level output on rear channels only to the amp
Then over can bus digital messages from radio to amp adjust the volume balance and fade
The crappy aftermarket can adapters ain’t smart enough to do that and new radio cannot generate the digital signals so volume becomes just decreasing overall amplitude like when a song gets quieter and as factory amp has only 2 channel input no way to half ass the fade
What you could do is replace factory amp with one that accepts 4 channel input from new factory head unit and then fade would work but you have to have 4 pairs of audio wires from head unit to new amp so need to add 4 wires for front output
There are also many oem amps that don’t rely on can bus that accept 4 channel input and could easily be adapted
The Bose amp used in Mercedes ml of late 1990s has that input and six paired output including sub
The WJ jeep infinity amp has four speaker level input channels and 6 output channels
The Hyundai Azera has 4 speaker level inputs and 11 outputs include a pair of subs and a pair of tweeters and even a center channel
It sounds great with any quality headunit and is about $20 at a u pull it yard
Sent from my iPhone using Tapatalk
Then over can bus digital messages from radio to amp adjust the volume balance and fade
The crappy aftermarket can adapters ain’t smart enough to do that and new radio cannot generate the digital signals so volume becomes just decreasing overall amplitude like when a song gets quieter and as factory amp has only 2 channel input no way to half ass the fade
What you could do is replace factory amp with one that accepts 4 channel input from new factory head unit and then fade would work but you have to have 4 pairs of audio wires from head unit to new amp so need to add 4 wires for front output
There are also many oem amps that don’t rely on can bus that accept 4 channel input and could easily be adapted
The Bose amp used in Mercedes ml of late 1990s has that input and six paired output including sub
The WJ jeep infinity amp has four speaker level input channels and 6 output channels
The Hyundai Azera has 4 speaker level inputs and 11 outputs include a pair of subs and a pair of tweeters and even a center channel
It sounds great with any quality headunit and is about $20 at a u pull it yard
Sent from my iPhone using Tapatalk
