les3002 0 Posted August 16, 2003 i have just put a amp on my 6x9s and they sound great, until i start the engine, when i do i get a horrible buzzing noise that increases frequency with revs, ive checked the earth to the amp it is earthed to bare metal in the boot. also i still get the inteferance regardless of volume of the head unit anyone got any ideas? Share this post Link to post Share on other sites
base-1 17 Posted August 16, 2003 sounds like interference from the alternator, halfrauds do a little alternator-mounted suppressor for about 3 quid, takes 5 mins to fit including getting tools out and putting away also, did you run power cable and RCA's down same side of the car? cos that will be how its interfering - run em on seperate sides, and see if that makes enough of a difference to not bother with the suppressor Share this post Link to post Share on other sites
Guest hux309 Posted August 16, 2003 also try ht wires with thicker silicone to help insulate any interference Share this post Link to post Share on other sites
les3002 0 Posted August 17, 2003 i was thinking ht leads myself but that suppressor is a good idea and my rca's are on opposite side to my power leads Share this post Link to post Share on other sites
Guest puggti Posted August 17, 2003 Get the supressor mine did this a while ago, when i did the electric windows it made interfernce to and the supressor sorted this out! Share this post Link to post Share on other sites
Robbie G 4 Posted August 17, 2003 WAIT before you spend money - suppressor yes fine, but this is like curing the symptoms instead of the disease. If you didnt get any noise through your audio system before you added the amp then im fairly sure that your problem is due to a ground loop somewhere. Try re-earthing your amp somewhere else, like directly to the battery. You need to eradicate the noise, not suppress it if you can. I have a different type of alternator noise - radiated whine on LW and MW radio bands. THIS is suppressor territory because it is not induced by the audio cables, but absorbed by the antenna into the system. Hopefully you should be able to solve the problem by a better method than a suppressor. Also try running a seperate thick earth cable from the head unit to the battery. The permanent noise unrelated to head unit volume level is probably ignition interference. Make sure you have decent resistor type HT leads and spark plugs, especially at the coil because it's quite tricky to reach under the fuel rail. Check and recheck connections at all points. I had popping from a loose HT lead at the ignition coil. Share this post Link to post Share on other sites
Guest hux309 Posted August 17, 2003 going by that it sounds like i need a supressor..only get it on mw and lw cheers robbie Share this post Link to post Share on other sites
Guest ADRIAN Posted August 17, 2003 If u want I'll send you a page that will solve all your stereo probs. mail me. Share this post Link to post Share on other sites
Guest Al-2 Posted August 17, 2003 Thicker silicone on the HT leads will make no difference, as silicone is radio-transparent. Sorry. What would help would be metal braiding over the leads and around the distributor cap, earthed at the ends, aircraft style. Works on Cessnas. The alternator suppressor sounds good though, I might have to fix one up. A high current choke in series with the alternator cable and a largeish capacitor between the output terminal and alternator body should do it. Time to raid the shed. Share this post Link to post Share on other sites
Simes 248 2 Cars Posted August 18, 2003 I've given up almost with trying to pin point this noise down. Mine is interference through amp but it is intermittent (argh) and is on the same circuit as rear lights, I find that turning the side lights on gets rid of it, but brake lights makes it louder!! and then sometimes I do not get any noise at all and then indicators can add to the mix and..and..and.!! Share this post Link to post Share on other sites
Guest ADRIAN Posted August 18, 2003 You also have check the amp. itself (even if its new) I had one that caused all the problems. Share this post Link to post Share on other sites
les3002 0 Posted August 18, 2003 right guys i undid the ground wire to the hu and grounded it directly to bare metal and it has made it alot better you can barely hear it now but its still there do you think a ground loop isolator would cure the rest of my problem? thanks for your help so far guys Share this post Link to post Share on other sites
Robbie G 4 Posted August 18, 2003 Ground it directly to the battery, and if it solves the problem find a way through the firewall (look at woosey's article on the main site) and earth it here. Make sure your amp ground is of similar quality if this fails to solve the problem. Experiment with different ground positions until you eliminate the potential difference between the two earthing points. I have earthed my head unit onto the firewall, to one of the bolts holding the carpet onto the firewall. Share this post Link to post Share on other sites
