I have Inspiron 15R SE with intel i5 and works on win 8 with tag No:50DM1X1 . I'm suffering with this laptop especially a lot with the Audio card (Connexent).
When I install the last updated drive or even any previous driver the speakers produce in many occasions a crackling and static noise. When I remove it and work on the default windows driver (High Definition Audio) the problem solved, but the Mic doesn't work well the sound from the mic is verrrrrrrrrrrrry low and there is a lot of background noise.
If you tried all of them and got the noise, but not with the native Windows driver, then it appears to be an issue with the Conexant driver versions. I don't know of a solution. You should report this issue to Dell so it will know a new driver or BIOS revision may be needed.
Jim Coates -- 15 years on the Dell Laptop Audio boards -- since 2/6/04