Problem With My Sub Set Up -No Sound

[GrayRabbit]

Hi,

Just hooked up an alpine 12" into the boot of my Mk2, I have used the same crappy amp as i used before in my last car but no sound. There is power to the amp and the protect light is off.  The remote is connected as is the power and the phonos from the head unit.  The ground is good.  i just cant figure out why no sound.  I thought the amp must be bolloxed so i borrowed another from a mate...exactly the same!  I have opened the sub to check the connections to the cone and they are fine, i have tried various configurations on the amp to bridge it for the sub..although i know how it was wired last time it was working.  i am left with a empty head! i can only guess the phonos are not getting a signal to the sub..

any thoughts would be appreciated

ta

Shawn

[Mr Blue]

any amp settings on the headunit switched off?

[GrayRabbit]

The head unit works fine on the 4 standard speakers ...im thinking the output phonos on the stereo are maybe inputs! as it doesnt say and it is a very old head unit...although there is no source setting on the head unit for an external signal??

[jasonpi]

i know some headunits have a seperate subwoofer switch and level may need to turn that on

[gibson]

easiest way i reckon to check is just park up next to a mate who has a sub/amp working in his car, unplug his phono cables from his amp and plug the ones that are running from your head unit into his amp (which is wired up in your mates car obviously)

If there is no sound you have narrowed it down to the headunit being inputs not outputs, the phono (rca) cabole being knackered, or lastly they are inputs on the head unit but they are just broke.

If there is sound then you know its not your headunit/phono cable but its summit with your amo

Hope it works (or at least makes sense  )

[GolfChick24]

yeah try and narrow down where the problem is. try powering the sub from your normal speaker connections to double check the sub is all working, then try powering your speakers with the amp and see if they work, then you will have noarrowed it down to an amp problem. I had this problem once I plugged in the sub and nothing but when i plugged it through the hu it worked fine, never did figure out what it was i upgraded not long after and paid more for the components so now everything works straight away, i love spending money!