How does HDMI affect Jitter

How Can HDMI avoid jitter?

Does LPCM over HDMI suffer from jitter?

I somehow stumbled across these from one of the AVSForum threads and wanted to get you guys thoughts about it. I do use HDMI from my PC to a Yamaha receiver for 2 channel audio among other things, but am no audiophile by any means. Is this all a bunch of audiophile jibberish?

It's mostly the same old jitter hysteria story, that we know. HDMI indeed doesn't treat audio as a first class citizen, its clock must be derived from the video clock. On the other hand we are talking about high tech TDMS links at up to 10 gbit/s rates! To be able to transmit at these rates engineers had to solve much worse problems than your usual grain of jitter. Stable transmission of (even HD) audio data rates is a joke compared to that. Of course audiophiles have to run in circles because the design is not "pure" enough for their taste (or mental capacity). In practice relatively low cost sender/receiver pairs as the Silicon Image HDMI 9134/9135 can already be manually distracted with insane amounts of jitter without showing any measurable artifacts at their outputs.

Most reported problems aren't probably jitter related problems, but broken implementations. HDMI can lower the overall data rate according to the video rate. If you don't take further provisions the audio channel can get slower than needed. The sending unit must accomodate that.

These articles all share a common failing. They are all composed of speculations based on weak generalizations. There are zero real-world facts presented. Let me give you some examples of real world facts:

(1) Bench tests. Bench testing jitter is not rocket science. Everybody with a PC can generate test signals and burn media containing those test signals. Everybody with a desktop PC has line level inputs that can be used to capture the types of audio signals found in home and studio audio systems. Evreybody who can google "audio rightmarkj" can obtain a full suite of audio test programs for zero additional cost..

(2) Well-designed listening tests, which means level-matching, time-synching, and bias controls, etc.



Yeah. Big time.

I have nothing to worry about then because there is always video along with the audio since I run dual monitors, with the HDMI output to a Yamaha RX-V663.