Audio diagnosis

[Howling]

So a bit of an odd one;

Sometimes (about half of the time tbh) when I start my Mustang, the audio is .... not-clean; like there's a bit of distortion on it. And this persists from the moment you start up until you turn it off, ie it doesn't get better over the drive. But sometimes I start up and the audio is perfect - and as before, doesn't change until next start.

It seems to distort more when it's cold (so generally morning starts) but if it was just temperature I'd have assumed that as the car warmed up that the audio would clear up; but whatever state it's in when you power it up is the state it stays in. I can't even tell which speaker it's coming from (if it's located on just one) - it kinda sounds like maybe the mid-dash speaker, could be the passenger side though.... Could also be all of them

Any tips for going about diagnosing this?

 

[Armageus]

You can use the Left/Right balance and Front/Back fade settings to try and work out if it's a specific speaker, in which case it could be a loose connection or an issue with a specific channel on the amp/stereo

If it's all speakers then sounds more like it could be interference from the alternator etc in which case could be a bad ground somewhere.

 

[jpaul]

You get the distortion before you even start the engine ? maybe make recordings with phone attached near different speakers to isolate if its one in particular or willing passenger ?
maybe a cone is deteriorating/split (had some bmw door speakers/mids that did that before they were upgarded to hertz)