Jump to content

Apple Ipod Thread (Merged Topic)


Velvet Glove

Recommended Posts

  • Gold Platinum Member
  • Member
  • Member For: 20y 6m 14d
  • Gender: Male
  • Location: Victoria

Cosmic Gate listeners understand pinch.gif

ahhh what a great tune that one is. Luv it.

Regarding the shockBox, I can 100% vouch for it as I had sligh wine in IPOD but when connecting my laptop via the lengthy cables from the boot the whine was so bad it was a joke. I started selling tickets to come and hear the whine. "Come and see the amazing ford xr with its awsome carputer thart has the craziest sound ever". I was making a fortune with people coming from all the lands too hear it until I installed (in about 1.5 mins) the shockBox. WOW it was better than amazing not only was the wine gona I swear there is a bit more midrange frequesies now. Now im poor because people dont come to hear my whine nemore. my business went broke but not I have great audio.

sorry , skip the above gist of story is GET THE shockBOX its not just a crapy volume booster (preamp) it does more. well worth the $99.00

All I know is theres a lot of whining going on n most of its from me laughing.gif

I feel for you , welcome to the world of hurt I was in. When I charged my laptop in car the BA screen went really noisy... There are ways that MAY fix it. The worst maybe stupid option is to but a pure sine wave inverter and use the 240v charger but that maybe overkill for most people. Another thing you can maybe try is a 12v USB hub (if you can find one) then use the usb cable to charge it??

PS FM transmitters arnt so great because FM quallity is well crap! This doesnt matter if you have low kbps MP3s but most of us have better MP3s than FM transmitter bandwidth allows.

I think FM allows 96 kbps and I could never listen to music less than 128kbps but most of my stuff is 192kbps.

I made a homemade FM transmitter now that was dodge.

Edited by iDagabond
Link to comment
Share on other sites

  • voy74656
  • Member
  • Member For: 21y 1m 23d
  • Location: Adelaide

Just came back from ford - they installed the 'black box' then got me to take precious for a test drive with all the wiring loose on the floor. Was just a box with a retractable audio cable that connects to the aux audio port and the mobile office connector for the mobile phone. I had a little look and it was just marked as a 'signal booster'. It only camouflaged the underlying problem by boosting the mp3 volume heaps but the underlying whine is still there. Got em to take it out and talk to ford again. :Doh:

Link to comment
Share on other sites

  • 3 weeks later...
  • Member
  • Member For: 19y 3m 23d
  • Gender: Male
  • Location: Brisvegas


...getting back to the alternator whine thing, since it's the cause of all this drama, I was thinking about the problem the other day and came up with something so ludicrously simple it just might work!
How about this:
The noise is on the +12V power feed and is caused by an AC ripple voltage on top of the desired 12V DC output from the alternator, due to the nature of the alternator and the way it makes power, yes?
Well anyway, The real problem is eliminating the unwanted ripple frequency which is modulating the output transistors of the ICC (I think). This is difficult, becuase it's not a single frequency that you can just "notch" out - it moves with engine RPM, as anyone will tell you.
So, you need a filter that moves with it, yes?
How about isolating that ripple noise by capacitively coupling it into an op amp configured as a buffer (unity gain), but on the Inverting input, so that what comes out the other end is an exact copy of the noise, 180 degrees out of phase?
You could then feed this into the ICC's signal input, and (with a bit of luck) all but cancel out the noise! w00t2.gif
If you wanted to get super elaborate, you might even build an independent power supply for the ICC using power transistors (or maybe even a regulator?) modulated by the inverted noise signal, thus canceling the noise on all inputs, since the ICC itself is now noise-free.

Is this too simple to be effective?
Have I overlooked something fundamental to the problem?
Is a simple Dick Smith condenser more than adequate and I should just be quiet?

Dunno. That's why I posted it up here for the geniuses to scrutinize.
</My2c>

Link to comment
Share on other sites

  • Donating Members
  • Member For: 18y 5m 15d
  • Gender: Male
  • Location: perth

shockF6,

I think im going to have to purchase one of these puppies. Any chance of showing a photo of what the finished cable looks like?

bonz

Link to comment
Share on other sites

  • Member
  • Member For: 19y 3m 5d
  • Location: Melbourne

Hi Bonz,

here is a photo of the box. Its pretty straight forward, you plug it in to the aux socket that's behind your fuse panel, then plug in the power and all that's left to do is plug in your ipod/pda/carputer etc.

Let me know if you need more info :bum:

post-7456-1165280746_thumb.jpg

Link to comment
Share on other sites

  • voy74656
  • Member
  • Member For: 21y 1m 23d
  • Location: Adelaide

How about isolating that ripple noise by capacitively coupling it into an op amp configured as a buffer (unity gain), but on the Inverting input, so that what comes out the other end is an exact copy of the noise, 180 degrees out of phase?
You could then feed this into the ICC's signal input, and (with a bit of luck) all but cancel out the noise!




Yup - an isolator that removes the rippling noise by capacitively coupling into an op amp, configured as a buffer via unity gain on an inverting input which outputs the incoming audio signal to a 180 degree copy but out of phase with the origional input

TOTALLY SIMPLE!! why didnt I think of that.... fool.gif
Link to comment
Share on other sites

  • Donating Members
  • Member For: 19y 4m 20d

I must admit that I did not ready every post work for word but my experience with my ipod has been nothing but favorable. I purchased the necessary connections from Ford for $90 (similar price as those fm transmitters on the market that a few users have installed) and there has been no hint of whine or distortion. Even with the air con and all the lights turned on in the evenings the system has not faulted in the slightest.

Take the time to purchase and install the connections from Ford and you will have the desired results :)

Cheers.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
  • Create New...
'