Technical Audio problem enabling subwoofer

[switch123]

I have a Punto with stock sound system 100w sub in boot and a sony mex-bt2500 HU.

The problem lies in enabling the sub in the boot which only seems to turn on when source is tuner or when af/ta is enabled. I have worked out the problem in that the sub uses the gray power antenna/ amp power on and expects a turn on control from this but the sony HU only uses the blue( connected to gray through iso) to power antenna. could i just splice together the gray cable on iso to switched power (yellow)?

 

[switch123]

bump no one knows if this is safe

 

[dumbledore]

Sound safe but why would you bother. Just keep the af/ta botton enabled all the time. The problem sounds with the head unit. Also the amp will then be turned on even when you do not want to listen to anything.

 

[s and b]

theoretically your plan sounds plausible but nobody wants the writ if your car self ignites
they have two amps in these boxes one for each channel and both channels use the same speaker cone
a very weird setup which to me seems like overkill just for bass

 

[SouLz]

I have a sony explode, I have to keep AF turned on in order for the 100W subwoofer to work. Also AF worked on my Vibe sub-woofer that i had wired to the RCA's output on the back of the HU.

AF means Alternative Frequencies which ideally can relate to the subwoofer so just keep it turned on and you can use it like an ON/OFF switch.

 

[switch123]

well i took a scotch block connector and splice on the iso the gray and blue and green pins 2+3 together and diconnected the blue wire from iso by taking pin out now it works perfectly no more forgetting to turn sub on.

 

[SouLz]

well i took a scotch block connector and splice on the iso the gray and blue and green pins 2+3 together and diconnected the blue wire from iso by taking pin out now it works perfectly no more forgetting to turn sub on.

AF shouldnt turn off when you turn stereo off anyway so once its on you wouldnt need to mess again.

 

[dumbledore]

well i took a scotch block connector and splice on the iso the gray and blue and green pins 2+3 together and diconnected the blue wire from iso by taking pin out now it works perfectly no more forgetting to turn sub on.

As I mentioned before your sub should now be permanently on the moment you turn on the ignition even it the head unit is off. Or am I missing something?

 

[SouLz]

As I mentioned before your sub should now be permanently on the moment you turn on the ignition even it the head unit is off. Or am I missing something?

Thats what i thought.. unless its permanently on full stop?

 

[switch123]

Thats what i thought.. unless its permanently on full stop?

nope the gray sub power wire is connected to the switched supply on the iso so sub only goes on when ignition is on. and to the previous comments i had a prob that af would randomly go off so this sorts that.

 

[dumbledore]

Thats what i thought.. unless its permanently on full stop?

That will be a disaster. However, he mentions he connects that to a switched power. Nevertheless, I will check the amp to make sure is off when the car is not running.

 

[switch123]

As I mentioned before your sub should now be permanently on the moment you turn on the ignition even it the head unit is off. Or am I missing something?

well technically yes but the hu is never off now because its also connected to switched power and any time im in car theres music or radio on.