FM reception?

[abefroman]

I have a 2000 323i with hk system. Recently, I installed a Xtant X603 amp, A/D/S/ sub, and Rainbow Pro speakers to run off the stock head unit. When playing a cd, or songs from my ipod, the system is killer. However, I've noticed that my FM reception is terrible. Stations that used to come in crystal clear, are barely coming in at all. Anyone else have this problem? If so, are there any fixes/things I should look for?

Thanks

[31st330i]

I found that my radio reception went to hell (especially AM - need that for news and traffic) when there was an amp and sub in my trunk. the deal is that your antennea is in the rear window and the electronics below it cause interferance. as soon as I removed the stereo (and retrofitted the stock HK system), the reception came back to normal.

that said, I think there's also a TSB for the little antennea amplifier thingy behind the left b pillar trim. here's a pic from my HK retrofit page. the device I'm talking about is the gray box with cables plugged into it:

http://www.mindspring.com/~pmbenn/images/hk-13.jpg

[abefroman]

Do you think it might be possible to shield it with Dynomat or something? WOuld switching to an aftermarket deck possibly help?

[31st330i]

don't think dynamat has a product that blocks interfearance.

replacing the head unit does not eliminate the problem of having electronics below the antennea. it might work, though, if the new head unit has a better tuner (with better noise rejection).

[JustinB181]

I just installed my amp and subs over the weekend and have noticed the FM reception has gotten worse,, anyone figured out how to fix this??

[AMG EATER]

Please help figuring out this, I got DDE's installed and the interferance is happening. My radio stations where I usually get good reception sucks now! PLEASE HELP! :cry:

[WarSong]

ever since my jl amp was installed in my trunk (under deck) my FM reception has gone to sh!t as well. when i disconnect the amp, the reception is fine... :( i haven't figured out what to do about it though. anyone have any info?

[JustinB181]

WarSOng me and you have the same exact problem, there has to be a soultion somewhere. Damn I may have to break out my electromagnetic fields books from engineeirng school and figure out if the amp or power wire is interfering with the fm radio waves or the antenna operation. I have a feeling that it has to do with the antenna not powering up though, does anyone know where the antenna gets its power from, if we disconected the factory amp and removed it will that effect the antenna? If so can we run another power source to it?

[1HOTBMW]

Damn, I thought that I something come loose with my new clarion head unit. When I first installed the HU my reception was fine, and after about two weeks I installed my JL sub and my JL amp in my trunk and now my reception is like sh*t. I didn't realize that it may be due to the sub and amp install until I read this thread. It is really annoying the hell out of me. Please if anyone knows a remedy for this please let us know. I'll try to disconnect the amp tomorrow to see if the reception gets any better. -Michael. :thumbup:

[EuroProjektzM3]

Well guys, I had MB QUART, 2 JL amps, and a pioneer flip out installed. When it was completed I noticed my FM reception was crappy compared to when I only had a Panasonic flip out before all this NEW ICE came in.
So I took it back in to the shop for them to check out engine noise in one of the speakers. They just straightened out the wires behind the deck, made the ground wire shorter, double checked all the wires and made sure everything was nice and secure. After that, everything was better than ever now. FM reception was back to normal, engine noise in my speakers were gone.

[JustinB181]

I am going to try and trim up all the wires, i have alot of extra wire ( I always do this for ease of moving stuff around) I will cut them to spec with out any extra wire and zip tie all of them and run them perpendicular to the back windshield to reduce the interference possibly as much as possible. Running them parallel with out twisting them may induce noise or interference.

[jetblack330ci]

I replaced the stock tweeters in mine and made no other mods and now I can hear the signal fade and crackle. I think that the system was so low-fi that the reception was bad but we just didnt hear it.

[WarSong]

hmm, seems like installing under the deck is the problem. any good alternative installation locations? :dunno:

[JustinB181]

lol.. unforunately I have to install under my deck unless i redo my entire setup. my speaker box is in my spare tire well with the amp behind it on the deck. I hope to find a solution this weekend.

[WarSong]

please let me know if you find a fix.

[gfeiner]

A low-tech cheap solution: Aluminum foil to act as shielding? :dunno:

[JustinB181]

anyone find a solution yet??

[chris b.]

bringing this back from the dead. i now have this problem myself.i checked my signal strength through the service mode on my radio and its weird-when the bass hits i loose recption,if the volume is low its ok.if the volume is turned up my reception goes bad. i checked my fault memory and have a radio antenna supply fault,but ive noticed that alot of e-46 that come in the shop do(ones without aftermarkett systems). and the fault only occured once
so i went to radio shack and got a capacitor and placed it on the antenna amplifier's power line,but no luck. then went and bought a capactior for the amplifier-no luck. next is to move the amplifier from under the deck after searching and reading it may be interfering(sp?) with the antenna in the glass.
gonna try this later tonight or tommorrow. ill post the results.

[ca1242]

Some class D amplifiers emmit FM interference. Since the antenna and antenna amplifier are on the driver's side of the car, best thing to do is get the amplifier as far away as possible (over battery area on side of car). Maybe mount the amp on the spare tire hole.

[chris b.]

yea.. thats what i was reading. im gonna try alternate locations when i get the chance. ill update if i come up with anything.

[skeelo34]

Anyone figure this thing out? I have the same problem. Is there an antenna booster that we could get?

[bobf]

I have two amps located on the back of the rear seat, one of which is a D class amp - no problem at all with FM reception.

AM is another story, but that is nothing to do with the amps - rear window arial has failed according to dealer meaning new rear window required :(

[chris b.]

i moved my amp from under the rear deck to the bottom of the rear seat back.
reception got better but still not great. still working on the problem,but really dont have the time.
cd's are my friend :lmao:
this really sucks if ya ask me.

[shagone]

i have a somewhat simmilar problem in my 99' 228i with premium H&K sound system. last weekend i replaced my factory blaupunkt tape deck with a new factory alpine cd head unit from an 02' for ipod capabilities and when i did my reception went to he11. the old tape deck had what looked like 2 antenna plugs but the alpine had only one so i plugged in the one that fit only.

does anyone know what the extra plug goes to? my original brochure says that the car has 3 fm diversity antennas to choose the best reception from and does so in miliseconds. any ideas on where the 3 antennas are located?

i plan on upgrading the speakers and adding aftermarket amps soon. ads speakers and either ads or xtant amps with the stock head unit.

As for sheilding the rear deck from interference you might try dynamat xtreme because it has a layer of aluminum foil on its face. just coat the entire underside of the trunk and deck lid and maybe even the top side under the package tray as well.

this will serve dual purposes. it will insulate against vibrations(cleaner tighter bass) and might block some of the interferrence to the antenna.

let me know if this sounds good or if better ideas have come up elswhere on this forum?

[Sshark]

shagone - Did you find a way to hook-up the second antenna plugs (the small plug)?

[jeffhixon]

I have the stock non-hk and my FM goes to sh!t when I turn on the rear window defroster, so I just don't use it. I'm putting in a new amp this week BTW. does anyone else get bad FM reception when the rear window defogger is on??

[ca1242]

You might want to try the other antenna. You can get an adaptor from any car stereo shop. There are only two antennas (I have never heard of a 3rd antenna, but if there is one, it could be inside the radio). The antenna is on the rear window traces.

i have a somewhat simmilar problem in my 99' 228i with premium H&K sound system. last weekend i replaced my factory blaupunkt tape deck with a new factory alpine cd head unit from an 02' for ipod capabilities and when i did my reception went to he11. the old tape deck had what looked like 2 antenna plugs but the alpine had only one so i plugged in the one that fit only.

does anyone know what the extra plug goes to? my original brochure says that the car has 3 fm diversity antennas to choose the best reception from and does so in miliseconds. any ideas on where the 3 antennas are located?

i plan on upgrading the speakers and adding aftermarket amps soon. ads speakers and either ads or xtant amps with the stock head unit.

As for sheilding the rear deck from interference you might try dynamat xtreme because it has a layer of aluminum foil on its face. just coat the entire underside of the trunk and deck lid and maybe even the top side under the package tray as well.

this will serve dual purposes. it will insulate against vibrations(cleaner tighter bass) and might block some of the interferrence to the antenna.

let me know if this sounds good or if better ideas have come up elswhere on this forum?

[ca1242]

I have the stock non-hk and my FM goes to sh!t when I turn on the rear window defroster, so I just don't use it. I'm putting in a new amp this week BTW. does anyone else get bad FM reception when the rear window defogger is on??

There is an antenna amplifier on the driver's side C-pillar, under the panel. Just remove the panel and tighten the antenna connectors going into the amplifier. This is a common problem.

[chris b.]

jeffhixon- you need a new rear glass. e-46's are common having this problem,the contacts on the side of the rear glass for the antenna get f-ed up and when the defroster is used it affects recpection badly.if you have cpo warranty or something go to a bmw dealer and complain about it,maybee theyll fix it.

by the way let me update my progress- i found that class "d" amplifiers will cause bad reception in our cars. i went with a class a/b amplifier and everything got sooo much better. amplifier placement also has a big role in reception problmes as well. try mounting it a far away from the right rear of the vehicle if possible since the fm antenna is on the r/r "c" pillar and the am is on the right "c" pillar. hope ive helped out.

[ca1242]

... actually, need to keep the amp away from the left (driver's) rear side.

jeffhixon- you need a new rear glass. e-46's are common having this problem,the contacts on the side of the rear glass for the antenna get f-ed up and when the defroster is used it affects recpection badly.if you have cpo warranty or something go to a bmw dealer and complain about it,maybee theyll fix it.

by the way let me update my progress- i found that class "d" amplifiers will cause bad reception in our cars. i went with a class a/b amplifier and everything got sooo much better. amplifier placement also has a big role in reception problmes as well. try mounting it a far away from the right rear of the vehicle if possible since the fm antenna is on the r/r "c" pillar and the am is on the right "c" pillar. hope ive helped out.

[chris b.]

your right^^^ ooops :lmao: :thumbup:

[jeffhixon]

Chris b.

thanks for the reply. There's no f'ing way in hell that I'm replacing the rear glass because of a bad connection that results in poor reception when the rear defrost is on. But i may f with the connections and try a little soldering... BTW, my amp is a class AB that should be here tomorrow. I'm just going to use it to run base through the rears. I had replaced the rears with some beefier 6.5"s. I think I'm gonna go with some Tang band 8"s soon... It will be a costom "JL stealth box" for cheap. If that's not enough, I'll get out the fiberglass and buy a dayton 10" and make an enclosure in the spare tire well. but I've got a fam, so trunk space is a concern.

[sna77]

shagone - Did you find a way to hook-up the second antenna plugs (the small plug)?


Well you can replace the antena amplifier:

http://forum.e46fanatics.com/showthread.php?t=387950


Although if there is a way to power the existing amplifier, that would be best. Any ideas??

[sna77]

Fixed it. =)

http://forum.e46fanatics.com/showthread.php?t=396343