HDMI - SPDIF convertor

DO you want a HDMI -SPDIF convertor

  • No

    Votes: 10 11.8%
  • yes < $200

    Votes: 62 72.9%
  • Yes > $200

    Votes: 13 15.3%

  • Total voters
    85
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Nikon1975,

I assume you mean my HT system........

I run a mixture of Crown and EV pro amplifiers (about 6,000 watts). Speakers are JBL and EV commercial cinema types. Upfront are 3 JBL 3632 ScreenArrays and I use 6 JBL 8340A as surrounds. Subs are 2 EV TL880D's

Processing is through BSS Soundweb 9088/9008 combo.

Cheers
 
Goodness me!
Thats a lot of power at home!
Have you ever measured how much power you actually use when the system is at full power?

I put the CRO aross my speaker outputs when I was totally pumping the stereo and was surprised to find that I was only using 15 Watts!
 
Erin.

If it had anything to do with loudness, I'd be deaf in an instant. This is all about headroom and therefore....clarity.😉

You can't use pro cinema stuff at home unless you have VERY big room. Otherwise the transducers will never reach full extension and the sound is awful. They take a lot of setting up - much more than the consumer stuff.

Ashaw. It was good to talk to you and I've asked the question. No response over night.
 
Kwikas, yes I know about headroom. You must have a big room!
Not knocking you, or your system.
I still recon 6000W is overkill at home. I find that pro-audio touring amps generally do not provide the sonic refinement of a well designed "hi fi" amp.
But I bet the bass slam you get is awesome. I would consider a touring amp on the LF if I had huge actively crossed over pair of speakers.
 
Before I offer too much potential mis-information about this, can you please confirm that:

1. You want the ability to strip out 5.1 (6 channels) and/or 7.1 (8 channels) of digital HD audio from the HDMI feed?
Yes, please.
2. You want the HD audio output to be in the S/PDIF format (RCA/Coax)?
That's a viable option. I2S would be fine, too. In worst case, I'd take analog.
3. You want the ability to handle up to 24/96 for each channel (BluRay)?
Would be nice, yes.

You've mentioned your surely impressive equipment, but I didn't get what piece of it actually strips the audio from the HDMI?

Jörg
 
It's been a while.

Kwikas, if I got you correct you have this DMI switch:
Dual output 4x2 HDMI Matrix switch with 7.1 Analog Audio output. Version 1.3, Full 1080P. Connect HDMI to HDTV and 7.1 Analog Audio to Audio reciever, 1RU mounts included
retrofitted with such an S/PDIF transmitter board:
3x S/PDIF Transceiver (In/Out)

Nice, thanks a lot for the pointers. Your solution dictates that audio is alread decoded into PCM in the HDMI signal. Thats not the case for all devices. For my satellite receiver I need to decode AC3. Plus, it would be very helpful to have basic audio processing in that box, like speaker selection, delay equalization, bass asignment, and nonetheless volume control.

Meanwhile the Gefen box is available:
http://www.gefen.com/kvm/dproduct.jsp?prod_id=8202

I have bought one, it's here since a few days. It's already open, I have identified the internal I2S. Luckily, they are volume controlled. So I will add 3 S/PDIF transmitters, then I'm happy. The outputs can go directly to DACs and power amps, the front channel ones to my existing stereo system.

Pictures are due next, stay tuned.

Jörg
 
Here's a picture of its guts:
Bild: img_1178v8kt.jpg - abload.de


An externally hosted image should be here but it was not working when we last tested it.


(Edit: I'm struggling with how to post pictures here. Click on the second link that looks kindof dead, when the picture opens click it again to get full size.)

On request, I'd do a more detailed one.

The video board hosts 3 chips from Silicon Image, one SiI9135 for an Rx (only one of its two channels is used, boo), and two SiI9134 for the two Tx channels.
The main board has a Micronas "chipset" for decoding and mixing, a MAS3529 and a MAP5401. For the latter I found no datasheet, can anybody help?
The CPU is an exotic one, Winbond W78E065A. Also, no information found.
The circuit looks nice, with buffers inbetween the boards, series resistors everywhere. (Mechanical quality is sub par, the buttons rattle in plenty of play, the IR receiver is recessed by ~2cm, bad paint job, don't place the lightweight remote near a draft.)

So long,
Jörg
 
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Unfortunately, the editing time window for my previous post is expired, here is a better link, without advertising:
img_1178v8kt.jpg


Jörg
 
Jorg,

How is your project proceeding? Have you got it up and running yet?

Nice, thanks a lot for the pointers. Your solution dictates that audio is alread decoded into PCM in the HDMI signal. Thats not the case for all devices. For my satellite receiver I need to decode AC3. Plus, it would be very helpful to have basic audio processing in that box, like speaker selection, delay equalization, bass asignment, and nonetheless volume control.

I only needed to get AES3 into my BSS soundwebs. The Soundwebs do the rest. If I could find a PRO DSP unit that had an HDMI input and gives me all of the DSP I need, I would buy it in a heartbeat. The problem is that HDMI is really consumer and AES/EBU is more for pro use. I just don't see anyone like BSS or EV putting HDMI into any of their DSP equipment.
 
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I can not confirm it wont work because i do not have any HDMI audio device capable of doing 7.1 24bit/192kHz. HDMI useses EDID to identify what your audio equipment supports. So currently i can only select 2.0 (TV).

I have gathered some information about my HD4550 HDMI card on the internet and found "Now the bandwidth limit of the ATI audio output is listed as 6.144MB/s, does this mean the maximum setting I can use is 7.1 (8) x 16bit x 48kHz = 6.144."

-"No, the specs on the AMD site is wrong. It supports up to 24bit/192kHz 8 channels."

Any one who can confim?
 
ATI uses an audio cip on their videocards to send the SPDIF out via HDMI. What capabilities is that cip reporting?
ATI says: "Integrated HD audio controller with up to 2 channel 48 KHz stereo or multi-channel (7.1) AC3 enabling a plug-and-play cable-less audio solution."
That means for me that is either 2 channel 48kHz PCM (I suppose 16bit and obvious no multichannel) or 7.1 AC3 pass-trough (therefore requiring an external decoder). No way that you can send 8 channels of PCM 24bit/192kHz, no matter what the bandwidth is.
 
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Well... It has "support" for HD audio - that means pass-trough, not decoding/encoding. I think that decoding those formats work just for the analog outputs, I doubt it can be routed back into the HDMI as multichannel PCM.
In fact, the card is "Compliant with HDMI v1.3a industrial standard -HDCP 1.2 compatible". I didn't test it, it is based on the CMI8788 cip with some generic SiI cip for HDMI injection.
 
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