How would you get the digital audio into the wireless transmitter?

 

I assume he would use the composite video input to input a coaxial digital audio signal. I bet it wouldn't work, but it would make for a nice experiment. I don't think the RF wireless gadgets are just like using a cable (since composite video and digital coax can be interchanged in a pinch). I don't ever have to use the wireless devices so my experience is limited, but I'm pretty sure they modulate/demodulate the signal to transfer it via airwaves. If that's the case it likely won't work.


Brent Huskins

 

OK, I was thinking the optical output. Anyway, your going to need a wireless transmitter that is capable of sending a digital signal across the air. I have not seen this. Your not going to use the standard stereo wireless transmitters because they have a left and a right channel input for your audio only and not a digital input. Unless you can show me a optical or coax digital connection capable transmitter.

 

Actually it all should come to transmitter bandwidth. Video signal (NTSC or PAL) has a band width of about 5MHz. That is a plenty of BW to send Digital Audio even for 5.1 channels. DTS (much higher data rate than AC-3) uses about 1.5Mbit/s data rate. With even as primitive modulation sceme as PCM it will not take 5MHz to transfer 1.5Mbit/s.

In other words; as long as max frequency coming out of COAX DIXITAL OUT is less than standard VIDEO OUT it could work. What I'm not so sure about is the stability of those video transmiters. If modulation/demod is not stable enough digital receiver will not be able to syncronize.

Yet another question is the signal level. If my PCM OUT overdrives the video transmitter, all goes to heck, but that can be adjusted too.

Well, I have to talk my friend in to this this weekend since he has the transmitter and I have the rest of the stuff.

I will post the results whenever I have got some.

 

Test came out positive.


As I thought, it worked like a dream. Here is the test setup:


JVC XV-S500 DVD Player

X-10 Wireless Video Transmitter (about 3 years old model)

Onkyo TX-DS575X Receiver


Digital Coax out is connected to Wireless Video in and in the other end Video out is connected to PCM Digital in. That simple!


With no problem receiver recognized the signal at the PCM input. Turning transmitter away from receiver causes loss of signal and sound mutes without cracks or other distortion. Re-alligning TX and RX leads to quick recovery.

I did not have change to run actual distance tests, but I bet it is better than video, which works thru walls and wooden floors.

Walking between the TX and RX does not cause any problems.


With this setup I could now set the DVD player close to my sofa with projector (minimize S-video cable length) and keep my receiver in the front close to speakers. Multi-room systems could use this too!?


I only tested one product combination, but since Digital Coax out is a standard and so is Video, I believe you should be able to make this work too.


Good Luck

 

That worked?

That's nice to know. So your A/V receiver on the receiving end of the dolby digital signal actually recognized the dd signal?.


I'm guessing you know this because your 5.1 lights on the A/V amp were nice and bright?

 

Yes. I played both Dolby Digital and DTS movies. DTS I had more concern with due to much higher data rate (More sound information), but both worked fine.

Since this IS digital connection, any problems are likely to cause total muting of sound. When intentionally turning the transmitter off and then on, my receiver recovered very quickly showing Dolby Surround for a fraction of a second and then full 5.1 DD. Of course all channels were clear and audible.