Land rover discovery 2 stereo upgrade

Hi guy, after much serching and not being able to find relevent infomation, i came across this site and hopefully you can help me. I have a landrover discovery 2 1998 ES with the Harmom Kardon high stereo, i have replaced the stereo with a "kenwood kdc-x7000dab" Now everything works, stalk controls ect ect, but i dont think it sounds as good as it should. tHis is the wires that im using "https://incartec.co.uk/landrover/1343/1033/2047/165/Browser.aspx" The problem i have is there is a hissing coming from the speakers, wasnt there before the HU swap. I have turned all the gains down on the amplifier integration interface, and whilst its still there is barely noticable. But if i remove the amplifier integration interface wiring it sounds so much better how i would expect it to, but the hissing is terrible. i know reading through the net there is no easy fix for background noise, but any ideas of simply fixes Thanks for your time

When you remove the interface harness are you using the deck's speaker wires or the RCA jacks?

Using the speaker wires, not the rca's

The adapter you posted the link to says it reduces speaker level signal to a lower level that can be used by the OEM amplifier. Try using the RCA jacks.

Metra calls for the 70-9400 harness. It has RCA jacks. Some of their harnesses with RCA jacks do not work properly. I have never used this harness, it may be one of the few that work properly with RCA level signals. http://metraonline.com/part/70-9400

Ok thanks for the advice, i brought a new bit of wiring and was hoping that it was per wired but its not, this is now what i have, any ideas of what wires go in to which hole

Stab the pins exactly like your other harness. Put the white where the white is on the other one. Put WHITE/ black where the WHITE/ black is on the other one, and so on.

ok, but they all seem to be black in a photo i have (on the car side)and surely they have to be paired?? or am i just being stupid........ thanks in advance

I will look at work tomorrow and see if I have the Metra harness. If I do, I will take a pic of it.

that would be great , thanks so much for your help