Hi Guys,
The speaker in the iPhone was fine. I had to replace the lightening cable, microphone flex cable. I did test the replacement speaker, but the sound was really distorted. So I kept the original apple phone.
I would recommend getting a genuine apple part, but thats difficult to source. Even the parts on this website aren't genuine parts.
I ordered mine from amazon UK for £6.
So its working now.
Thanks for your replies guys.