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KOSS KS4102 Digital Coax Delays

2669 Views 18 Replies 8 Participants Last post by  noelb
My Koss 4102 has no delay when receiving analog audio from my Cable HD STB but does have a 1/4-3/4 second delay when receiving Dolby 5.1 from the same cable STB via digital coax. The video from the cable STB is going to a HDTV and that is where the delay is noticable.

I have not yet been unable to get a clear answer from KOSS as to if this is a know problem and if it is there a soltuon.

Anybody else have this problem or any information as to a solution.
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I noticed this with DD5.1 coming from the cable box. Setting the cable box to PCM digital out has no sync delay.

So, is it the cable box or receiver?
The problem was a delay in the Koss unit and Koss took the unit back and gave me a refund.
Why would PCM digital in have no sync delay and Dolby Digital in have delay?
because PCM is esentialy analog while Dolby Digital has to be decoded.
extremely inexpensive HTiB systems, especially ones from Koss, are notorious for delays like that. you get what you pay for, and it's very hard to find a HTiB system with an optical input for under $150, so you have to expect that it's not going to be the best quality. i know it sucks, especially when you don't have money to throw away, but unfortunately that's how things are...
I'll just use PCM and Dolby PLII until I decide to upgrade again. All I had before was analog in and dolby prologic I.
Big difference between PLI and PLII isn't there? :cool:
Yea, PLII is almost as good as 5.1 Much more spatiality and more out of the rear surround speakers. Before, it was hard to tell if there was anything coming out of the surround on the magnavox mrd200. I can live with digital PCM and PLII for now. I do wish DD5.1 worked on external digital in....
Dear Mike,

Thank you for contacting Koss Customer Support.

We understand from your e-mail that, you are experiencing a audio- video

synchronization problem with the KS4102 home theater system.

We suggest that, you reset the unit to resolve the issue. To reset the unit

follow the procedure.

1. Make sure there is no disc inside.

2. Turn the unit off.

3. Unplug the main Power chord of the DVD player from the power outlet. Wait

for 20 seconds and replug the power chord to power outlet.

4. Select the DVD mode by pushing the "DVD" button on the remote control of

the DVD player.

5. Now enter the digits "7" , "6", "4", "1", "9" using the remote control.

- The VFD will display " Goodbye" & power off.

- Press the "Power" button again.

Koss Service Center

11733 Missouri Bottom Road,

Hazelwood, MO 63042

Phone 1-800-726-3801

Please feel free to contact us for further assistance.

"When you reply to our mail, please use the reply button in your email

program to

include the text of previous correspondence. This will help us process your

query efficiently."

KOSS Customer Support

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I'll try it after I get home from work. Koss customer service asnwered within a day of me sending in the question. Pretty good.
KOSS upport tried all sorts of solutions with me including the one sent to Mike.

Finnaly after checking with their engineers they stated that there only solution was for me to switch to analog audio since the delay could not be eliminated.

They then had me send a copy of my receipt and then send the unit back to them and they refunded to me what I had paid.
So...about the crappy KOSS HTIB system:

Through the help of Koss customer service, which is comparably much better than most, I have found a fix to the digital delay problem with the KS4102 HTIB. This is a pain for sure, but it works. First, follow the previous instructions and reset your receiver. Once you have your receiver reset, leave it on the DVD screen (so that you can see the following steps take place). At that point in time, go to the faq page regarding the system:

Go to the koss-av website, select faq's under customer support, select the fifth option down (at the bottom of the page), then select the third question.

Download the zip file, and extract the files. Burn them, using roxio, nero, windows, etc to a cd. Using my roommate's windows laptop (I'm a mac user, but wasn't sure if it would work properly), I just selected the newly extracted files and copied them to a cd to be burned.

Upon burning the two files to the cd, load the disc. It may cause a little stir with your screen for a sec, but that's okay. Allow the CD to load the software fully, and then power down and then power up your system. NOW FOR THE GOOD PART! Go to a channel using your digital cable box where someone is talking, make sure your settings on the cable box are for dolby digital, and select av1/2 on the receiver with either the coax or optical input selected.


Hope this helps,

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I am glad to hear that Koss has finally resolved this problem. Their support staff worked with their engineers and they did admit the problem last year but did not have a solution at that time.

The allowed me to return my system directly to them and refunded me the price I paid which I put towards the purchse of another brand of HTIB.
Cool. Gonna try it soon and see how DD5.1 works with it
Got it upgraded. Much better. I can only see a slight delay with voices now but I think that has to do with time difference betwen video and audio being processed by two different sources. The STB dolby decoder might have better sync than the koss. Need to do some other testing between DD5.1 and Dolby PLII with PCM.
PCM with Dolby PLII lip sync is near perfect (test with audio from tv speakers to see if there is any delay). Before, I could hear a delay between the tv speakers and the koss. Need to do some testing with DD5.1 but I think it is still off by a hair.
I installed the latest firmware update from KOSS and it broke DTS playback!

All my DVD's that have DTS soundtrack playback silent now :mad:

If I switch to standard Dolby Digital the soundtrack works. This was definitely working for me just before installing the latest firmware for the KOSS 4102 so Im pretty sure thats what caused it.

Can any one else test this and report back if DTS works?
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