[sanchezj14]

hi guys,
I previously posted a thread on a problem Ive been having with my Logic 7 but got no replies. I have a month left on my warranty from the used car dealer and i would like to figure this out so i don't have to come out of pocket if something must be replaced. I have a 2008 335xi with the i drive Logic 7 system and I use an aux cable for the ipod. There is a popping noise almost like a fart noise coming from the speakers. This is only at certain times or at certain bass notes. The fart noise will come on instead of the bass note but when the volume is a little lower and when i first start driving the car, the bass from both subs sounds good. The distortion/noise will mainly come from the sub under the driver seat but seems to travel to the left side as well. I am wondering if this is an amp problem or if it is the subs. When i brought it to them, he said the bass was too high. I now have the bass flat on the equalizer and the bass control and the sound is still there. Please help me

[JayKay335i]

Start by replacing the mini cable. Turn the equalizer off on the ipod in the settings menu.

[sanchezj14]

so you think its the cable? Its a hard noise to replicate. I listen to mainly hip hop r&b so i like a lot of bass. The subs keep making the noise and it confuses me because the subs still produce notes so i know there not blown but it makes these fart noises in place of some bass notes.

[Sherj]

I have the same problem, I think it possible could be the the song itself or the wire. Since the "farting" noise is irradic.

[fdriller9]

I have gotten a rattling/distortion sound from certain songs on my l7 system, volume high. Although it is rare and hasn't occurred for a while.

I would first check connections at both the amp and the speaker.

Check if the speakers are blown. Not likely since you said it is not constant.

You AUX input may be faulty. Do other sources create the sound you're referring to? If not, it is a problem with your AUX port/3.5pm cable you're using.

Make sure your iPod EQ is off.

Are you mp3s good quality? Where do you get them from.

The noise may also be from the speakers inability to play the frequency. The underwear subs play from 150hz down to around 30hz. Anything below that, the L7 woofers have trouble producing.

[JayKay335i]

It could be a lot of things. Could be you blasting it. While the stock logic 7 is OK, the subs aren't really subs as they have a pretty crappy frequency response and dont make it too far down the spectrum. I know when I listen to my ipod I leave the cord hanging out and put it in the center where I can see it, closing the lid on the cord. It would be a start. The equalizer on the ipod also makes a big difference. Along with the actual quality of the song. Chances are theres nothing wrong with your system and the songs your listening to produce a lot of frequencies that the underseat subs cant respond to, along with artificial sounding bass added to the song. Try upgrading them.

[sanchezj14]

Ok. Does yours come from the driver side sub and then switch to the right side? The noise will usually mainly occur on the left sub but other times it sounds like its coming from the left as well. I never would have guessed that a wire would be the cause of that bad noise.

[sanchezj14]

I download my songs from frostwire and from internet websites. The sounds sometimes does occur when a cd is on but i usually just have the aux on. How would i check the connections? I know that the amp is in the trunk on the left. I just wanted to make sure it was not a blown speaker or faulty amp because as i said before i do not want to pay for the repair. I usually have my ipod eq on acoustic.

[PsychoSlug]

My Logic7 system produces bass that actually hurts my ears at mid to high volumes. How others feel that it is insufficient is beyond me.

I'd check your cable. I dump all my songs on the hard drive. When I do use the iPod, I need to wiggle the cable or experience similar problems that you are.

[sanchezj14]

have any of you guys upgraded the subs? I see a lot of people changing them to earthquakes and you have to take out the whole seat without damaging the air bag. How hard is the install? I had a 12" kicker L7 in my last bmw so these subs do take some getting used to. So you guys think the best thing would probably be just to upgrade the subs?

[fdriller9]

If it's happenig with different sources it has to be your Head unit, amp, speakers, or your connections.

You have to get a T50 torx bit and take the 4 screws out of the 4 corners of the seat. Then unscrew the 6? Philips head screws for the woofer grill. You then have access to the woofer which is held in by 4 torx screws...either 15 or 20 torx bits, can't remember. Then you can check the connection which should be facing toward you.

[fdriller9]

Don't go upgrading yet...you need to find out if this is system related. If it is, then you'll have the same problem with the bew subs.

BTW, if you unplug the airbag under the seat (yellow harness), disconnect the battery or else you'll trip the airbag light on your dash.

[sanchezj14]

thank you for the info. How would i be able to check if its the head unit or the other audio components?

[fdriller9]

If you're asking that question I would have a pro look at it. I'm not saying you are incapable of doing it yourself, I'm just saying that you probably won't have the equipment to test the components individually.

You can start by unplugging the woofers and makin sure the sound does not come from the door speakers.

If not then you know it's the woofers. However it could just be the wiring. So the you would need to wire the woofers directly to the amp.

There's allot more you can do. I see your in NY, I'm going home to Jersey this weekend. Im about 20 mins from NYC, i can meet up with you and take a look of you want.

[sanchezj14]

thanks for all the answers and i appreciate the offer i am actually about 2 and a half hours from the bronx so it is hard to get down to NYC. I guess i would have to take it to a car audio place?

[reign528]

I am actually taking my car to BMW next week for the same exact issue. I hear a distortion sound from my logic 7 sound system when its cranked past a certain volume on certain freqs. Im not sure if I blew a speaker or something or where exactly it was even coming from. Funny thing is that it does this w/ CD's, iPod via OEM iPod cable and iPod via AUX....

So maybe my speakers arent blown or messed up like I thought...

BTW I do have 2 12in Alpine subs in the trunk (They sound amazing) Its just annoying to hear the distortion sound because I want to crank up my stereo and hear more bass from my trunk subs and less bass from my car speakers...

I dont want to add a crossover because I dont want to splice any wires... The car is still under warranty.

[fdriller9]

Yea I think that's your best bet...if you mention you want to get some new underseats installed maybe the shop will troubleshoot it for free.

[fdriller9]

Originally Posted by reign528

I am actually taking my car to BMW next week for the same exact issue. I hear a distortion sound from my logic 7 sound system when its cranked past a certain volume on certain freqs. Im not sure if I blew a speaker or something or where exactly it was even coming from. Funny thing is that it does this w/ CD's, iPod via OEM iPod cable and iPod via AUX....

So maybe my speakers arent blown or messed up like I thought...

BTW I do have 2 12in Alpine subs in the trunk (They sound amazing) Its just annoying to hear the distortion sound because I want to crank up my stereo and hear more bass from my trunk subs and less bass from my car speakers...

I dont want to add a crossover because I dont want to splice any wires... The car is still under warranty.

You can get Technics harness that is plug and play. Comes with a LOC already spliced in.

[pscmj84]

Is your L7 in music or movie processing mode? I was getting random garbled noises when I had either of those modes checked. Disabling those processing modes cleared up the issue.

If that works for you, it may be the amplifer for the L7. Since it was such a sporatic problem for me, the dealer couldn't replicate the issue unfortunately and now I'm out of warranty. I can't find it now, but awhile back someone was able to get their dealer to replace their amp. I think it had something to do with the amp having trouble with the handling all the channels involved with the music and movie modes.

[sanchezj14]

OK please let me know what the dealer says. The 2 modes for me are concert and theater. I usually have theater on but even when i turn it off, the sound is there. Usually, when i just have the car in the first mode for radio use, I can pump the Logic 7 and most of the time, it wont make the noise but the minute i turn the ignition on or i turn the car on, The noise will come on, depending on how long i had it playing for. Its like the sounds comes on when the system has been on for a while. It sounds really bad on certain bass notes and the farting noise that comes out of the sub is embarrassing when people are in my car.

[Technic]

Originally Posted by sanchezj14

hi guys,
I previously posted a thread on a problem Ive been having with my Logic 7 but got no replies. I have a month left on my warranty from the used car dealer and i would like to figure this out so i don't have to come out of pocket if something must be replaced. I have a 2008 335xi with the i drive Logic 7 system and I use an aux cable for the ipod. There is a popping noise almost like a fart noise coming from the speakers. This is only at certain times or at certain bass notes. The fart noise will come on instead of the bass note but when the volume is a little lower and when i first start driving the car, the bass from both subs sounds good. The distortion/noise will mainly come from the sub under the driver seat but seems to travel to the left side as well. I am wondering if this is an amp problem or if it is the subs. When i brought it to them, he said the bass was too high. I now have the bass flat on the equalizer and the bass control and the sound is still there. Please help me

When you use the AUX input you need to understand that what you are doing is feeding an already amplified signal into your OEM system. In other words, you will have to match that amplified signal level to whatever input level your OEM system tolerates. And you do that by adjusting both the AUX device volume and the OEM system volume.

This always been the main problem with any AUX input, in any car.

When you use the OEM USB port you are sending both a digital (control) and an analog (sound) signal to the OEM system. The reason that the USB port sounds better than pure AUX is that among the digital messages there is a message to set the USB player AUX volume to match the OEM system volume level. Thus the level mismatch does not happen, and bass "farts" are not heard as much.

This could be the major part of your problem, the minor part of your problem could be MP3 songs that are clipping. You can fix any clipping by either using the Sound Check option in your iPod (normalize all your songs to a non-clipping level automatically), set the volume lower to only those particular songs that you hear the bass clipping with the iPod or use MP3gain (www.mp3gain.com) to set all or some of your songs to a particular volume level.

There are editing MP3 software in the market that allow you to do more than just volume normalization to your songs, for example you can set your own EQ curve to each song with more bands than what the iPod provides.

[sanchezj14]

thanks for the info i will try it again tomorrow on cd mode to see if it is mainly the aux or the wire. Today, I had the bass up when i just had the car in radio mode and it was bumping. The minute i turned the car on and then turned it off, the farting noise was present.