[briers]

Does anyone else get this annoying hiss?

I don't have a USB port for idrive so aux is my only option and the hiss really spoils the sound.

Also what's the thing in the armrest, says tdu or something like that.

[Kerr]

All iPhones do it. I've had 5 connected to my aux and they all did it. Plenty of other people have complained about it too. My new phone is superb though.

Turn the iPhone volume to max and it cuts down on the hissing but it's always going to be there.

With good earphones you hear the background noise from iPhone and iPods too. They don't perform too well with sound.

[ed335d]

You need something like this:

http://www.amazon.co.uk/Belkin-Auto-...337382&sr=8-76

[hogbmw]

My 3gs didnt do it, but when I "upgraded" to a 4 it does. Pain in the butt I have to use the usb/aux dongle cord and scroll through like 200 artists every time I want to pick something.
Asked dealer about it when I took it in for some other stuff saturday and was less than happy with the answer.. nothing they could do.

[gIzzE]

Not only that, my 4s is now picking up alternator whine!!
As soon as I unplug the phone from the aux it ends completely.

Gutted.

[Billyray911]

I think it's because you're using equipment that isn't made for an I phone ie you get the same interference sometimes on docking stations that aren't specifically made for the phone,but are for an iPod.
Usually,by turning the phone to airplane mode,this will stop any interference-not much use I know!
I use a Kensington liquid aux with no issues...

[Billyray911]

That's on a IP4 using 5.1

[jimmylad]

using a nokia 5800 music phone though my aux input & when I connect it asks me what I want the output for so I select "line out" which seems to boost the gain and no hiss or alternator noises at all.

One question..... do you have anything charging in the car ?

Not really a comparison but my tranny van has a tom tom wired in through aux & sometimes the interference is horrendous especially through the radio. Took me ages to work out it was the 12v charger for the tom tom so I unplug it on the go & leave it charging overnight.

[chanlon1]

I had exactly the same problem and discovered a product that solves it.

A Ground Loop Isolator.

I bought mine from www.Car-Vision.co.uk for about £10, but looking on their site they dont appear to have anymore - only more expensive ones.

I did some something more or less identical on amazon: http://www.amazon.co.uk/Ground-Loop-.../dp/9792403817

Been using it for well over a year and has completely removed any additional noise

[Boyd1963]

Originally Posted by chanlon1

I had exactly the same problem and discovered a product that solves it.

A Ground Loop Isolator.

I bought mine from www.Car-Vision.co.uk for about £10, but looking on their site they dont appear to have anymore - only more expensive ones.

I did some something more or less identical on amazon: http://www.amazon.co.uk/Ground-Loop-.../dp/9792403817

Been using it for well over a year and has completely removed any additional noise

+1

I used to use one of those on my Saab's Aux in

[briers]

I did buy a line out for my 4s and it does solve the hiss but it has introduced a new problem.

It's like the iPhone volume has a setting of 12/10 on the line out with no way to adjust it.

I now get distortion on all songs at certain points, like when the song volume increases or at certain frequencies. It is worse than the hiss.

I can replicate it using the normal headphone cable socket too, along with the his, if i turn up the volume to max it starts to distort.

[Kerr]

Do those not just compress the sound to hide the hissing?

Pretty sure there is no way of removing the sound of the hiss without removing other frequencies in the sound too.

Hence why it will never sound right.

[gIzzE]

Originally Posted by briers

I did buy a line out for my 4s and it does solve the hiss but it has introduced a new problem.

It's like the iPhone volume has a setting of 12/10 on the line out with no way to adjust it.

I now get distortion on all songs at certain points, like when the song volume increases or at certain frequencies. It is worse than the hiss.

I can replicate it using the normal headphone cable socket too, along with the his, if i turn up the volume to max it starts to distort.

Then you aux input is set too high, or you have taken the sound check off on the iPhone and probably have the EQ on.

The line level does not clip if the EQ is off.

[flyfs6]

As always superb advice Gizze.

[gIzzE]

Apple got a lot of stick before ios5 as their EQ reduced the volume.

If you wanted Bass Boost for instance you would maybe raise the 20, 80, 120hz points by 3db, however, what the iPod did was lower everything else by 3db, so you were not getting more bass but less of everything else.

It did this as the iPod has a really low power output so there was nothing left in reserve, but reducing the gain was a bit of a problem as it was then too quiet a lot of the time.

From iOS5 they now do raise the curve rather than drop it, but if your recording is already at the limit it will clip (distort), and most commercial stuff these days is already pushed to the limit, if not beyond.

Turning on the Sound Check brings it back to how it was previously.

I don't think the EQ worked on the line out in ios4, but not 100% on that.

[gIzzE]

Also, the ipod line out needs you to set the aux to the middle setting, any higher and you will clip the input with most modern material.