Best picture and sound

i assume you are hooking up from tv to receiver with an optical cable? Check the settings on your tv. Most tv's have a setting to turn on/off the optical audio output

you can alternatively hook RCA cables to the cable box/satellite receiver or to the dvd/Blueray player

Get thje proper hook up cables then it might work,

Hi if there is an optical out on the television i would use that direct to your Harmon Kardon AVR 125, the sound would be in sync with picture, as the source is the same.

hook up the ps3 to the 5.1 and then run an audio cable of some kind from 5.1 to the tv

It is either a mismatch or improper ground connection.
Try correcting it by putting a ground line at your AVR
254.

in what display i need to put reciver when i use the optical digetal

I am attaching some pictures that will show a couple of wiring schemes based on the type of home theater you have. If you have questions with the set up of your HK receiver, please reply with those questions prior to rating your help.

I think I had the same problem. This is how I fixed it.

I have my vizio 42 hooked up to a Harmon Kardon surround sound, and the digital cable box. Essentially, I can adjust the volume 3 ways - through the tv, cable box or av receiver. The humming sound happens when you have the volume maxed out on the av receiver and not the cable box.

For example, the sound level on my Harmon Kardon goes from -10 (lowest) to 10 (loudest), with 0 being the middle ground. The buzzing was happening when the Harmon Kardon was set to 10, and I was using the cable box volume to adjust the sound. To fix it, I turned down the volume on my receiver to 0, which may be about 50% max volume of the receiver. Then, I switched devices and used the volume on my cable box. This got rid of the static I was getting. Hope that helps.

plug eash units sound in red whites from dvd tv main out the set speaker wires in place front ch a ok turn it on make sure ch a speakers on only select corect video input dvd ect turn it up