Film-Tech Forum ARCHIVE: 6 channel to hdmi adapter?

This is topic 6 channel to hdmi adapter? in forum The Afterlife at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=12;t=001060

Posted by Louis Bornwasser (Member # 3063) on 08-13-2014, 01:36 PM:

I have 6 channel analog on RCA plugs that needs to convert to hdmi. The hdmi receiver is used in a cry room situation. "New" receiver does not have analog inputs for more than 2 channels.

Does anyone make such a device?

Posted by Carsten Kurz (Member # 5396) on 08-13-2014, 04:16 PM:

I haven't seen them with discrete multichannel audio inputs. One solution could be an SDI-Audio Embedder followed by an SDI-HDMI converter. Could be in the 300-500US$ range.

Stereo HDMI Audio Embedders can be bought cheaply.

Typically, these embedders need a valid video signal at an input, as there is no audio-only HDMI transmission. Some have a built-in black generator if audio-only conversion is needed.

Do a search for SDI or HDMI 'audio embedders'.

There is an expensive digital-only (4/8ch AES-> HDMI) converter available from Arvus. Although I am not sure wether it was actually really available, it looked like a vapour-ware product for a while. I have seen quotes around 1200US$.

- Carsten

Posted by Frank Angel (Member # 248) on 08-13-2014, 08:12 PM:

Lou, do you really need 6 channels in a cry room? Wouldn't stereo do? After all, babies in there are for the most part wailing.

A theatre I worked years ago had a cry room; we ran lots of 4trk mag, and they just got a LCR mix-down to mono.

Posted by Louis Bornwasser (Member # 3063) on 08-15-2014, 07:11 AM:

They are repurposing the room as an adult beverage room and $20 tickets. (No, I think it will be a disaster as well) Still that is what they want.

Older home receivers have the 5 RCA jacks on the back. The plan was to just buy a new one. Guess what? They are now all-hdmi. No RCA plugs except of real cheap stuff.

Posted by Alan Gouger (Member # 543) on 08-15-2014, 07:53 AM:

Not RCA analog input but....
http://aes-hdmi.com/aes-2h.html

Posted by Carsten Kurz (Member # 5396) on 08-15-2014, 08:42 AM:

I just bought a used Marantz AV receiver on ebay. It has analog discrete inputs and outputs, with basic mixdown options if less than an 5.1/7.1 speaker config is used.

I payed around 400US$ for it. And that is still a higher class model (SR5007). Sure you could get something similar for even less money. Where does the analog 5.1 audio come from?

- Carsten

Posted by Louis Bornwasser (Member # 3063) on 08-16-2014, 10:06 AM:

It is a resistive mixdown from the main bi-amp outputs of the cinema amplifiers. EQ in room is quite gentle. 3x8330 for "window" speakers and 2 small speakers for surrounds.

I had thought about the output of the CP-500, but I did not want it outside the booth where any moron could kill screen sound. The system sounds quite good, but is currently running on a 16 year old system that has a channel missing.

Posted by Carsten Kurz (Member # 5396) on 08-16-2014, 08:16 PM:

Hmm, you could feed the output of the CP500 through a couple of split transformers/DI-Boxes, so the main screen sound would be safe. But anyway, a suitable AV receiver should do the job. I just recently did a search for units with discrete multichannel analog ins, and still found a few. Mentioned Marantz receivers have suitable amps for 8330 and can be bought new for around 500-700US$. It's a compact solution then. One unit, one volume control, basic options for EQ, etc., and alternative inputs. They even have RS232 and could be automated from the booth if needed.

There is a difference, though between units - some just offer a sideway into the main amps, bypassing all other inputs, EQ, etc., while some have the analog multichannel inputs added as a regular input source, with channel mapping, EQ, delay, etc. The Marantz receivers do it that way, while I think the Yamahas RV have very limited processing available for the multichannel inputs.

- Carsten

Posted by Louis Bornwasser (Member # 3063) on 08-17-2014, 07:26 AM:

Audio in, volume control, and amplifiers will do it. I think they bought a Marantz off of Amazon. Many thanks.