Bad sound quality (sizzling) on iPhone speakers

[iSpiritus]

Hi guys new here and to music production. I just finished working on an edm track and I am having some issues with sound quality on my iphone speakers. When I play the track on my speakers it sounds like it's playing at a really low audio quality setting. It sounds sort of muffled and distorted with sizzling in the high end. I have tested the track in my car, my speakers I mix with, laptop speakers, external computer speakers, my Nexus 7 tablet and my iphone headphones. It sounds crystal clear on all of those but it sounds awful on my iphone speakers. The speakers aren't bad because I tested one of my other tracks on it right after and it sounded just fine. I'm thinking it may be something in the production stage but I'm not quite sure what (It seems to be coming from the sounds with high end frequencies). Do phone speakers have a weird frequency range that they play at? Thanks for the help!

Also not sure if I posted this in the right area so I apologize if I didn't

[yur2die4]

Drop the finalized wav file into Live, unwarped. Bare for fx, absolutely nothing on any channel.

Then add a Utility and bring the Width down to Zero. Do you get similar issues?

[iSpiritus]

Problem is still there after lowering the width on the utility. I have been experimenting with other methods in the mean time. I filtered out frequencies from low mids and highs in different tracks and tested them individually. The track I tested with the filtered out highs seemed to have the most impact on removing the issue, it was almost gone. I filtered out all frequencies from 22k down to 13k kHtz. I expect if I go lower it will remove the rest that are causing the problem. The only issue I need to figure out now is how I can remove those frequencies that are causing issues without totally cutting out the high end of my track. I've looked at the spectrum tool and there doesn't seem to be any weird spikes in frequencies in the higher end everything seems normal.

[yur2die4]

So you are saying that the problem is not there, when played back on a stereo speaker system. Including your computer.

But from an iPhone speaker, the problem does exist.

When you add the utility and set width to zero, does that cause the problem to happen on the computer? Or only cause the problem to happen on your phone later?

It sounds like you might have something that does mid/side stereo field width expansion etc. that is making half your track disappear when you play it back summed to mono.

[iSpiritus]

Before I saw this I isolated the problem to my synth patches that I had made but I could't figure out why they were the issue. Now that you say that however I did have mid/side eq'ing done to them to thicken them up a bit. I will see if removing it solves the issue. I guess I will have to find another means to thicken them up or play with the eq to boost in other areas that won't cause an issue.