Originally Posted by amirm
I apologize as my two-digit IQ is not enabling me to understand your post. But I did note the reference to the Onkyo HDMI review from NWAVguy.
Please forgive my lack of clarity. There was no intent to be rude. I didn't realize that you possess a double digit IQ. I'm not sure why you refer to NWAVguy and cite from the Archimago website. In any account, in my previous post I attempted to illustrate that you were:
- *previously* dismissive of the archimago hdmi/optical measurements (which demonstrate the inaudibility of hdmi jitter) on the grounds of poor speculation (computer soundcards aren't properly calibrated and the authors measurements are invalid because a soundcard was used; and claiming that measurement of the Onkyo model 1009 is invalid because you obtained different measurements with product 8xx)
- dishonest when citing from the website (citing the author "hdmi is quite jittery," but ommitting that he/she indicated "inaudibly jittery")
- hypocritical in that you claimed the archimago author's measurements are invalid in a previous discussion on the topic of jitter, but in this discussion embrace his information on the basis that it matches your opinion and because he is, like you, an engineer
IOW, your reasoning is as useful as screen door on a submarine; regardless of IQ and other credentials that you bring to the conversation. Earlier, you warned others against listening to some dude citing tidbits on the Internet. Consider that its YOU who loses credibility when you weakly cite from the SAME source as the dude; quoting a portion that suits your belief, while ignoring the more substantial portions that doesn't. Tut, tut.
Are these 'Internet tidbits' valid, or are they just unworthy bits from unworthy tids?
I did see this. The measurement involves analog connectivity to the sound source, not hdmi.
Originally Posted by amirm
Here, he is testing the analog pass-through in the Onkyo TX-NR1009 AVR. Initially he finds it to have excellent performance with noise levels that are down some 110 db. But a remarkable thing happens when he hooks up a Blu-ray player to its HDMI input and connects the HDMI output to his display:
As excited as I am about those results above, a modern AV receiver is meant to process HDMI and be connected to a TV. This receiver has a HDMI "passthrough" which is essentially always in operation and for most people, it would not be left in "Pure Audio" mode with all the video gear disconnected. As such, look what happens when I connect my LG 55LW5600 TV (55" passive 3D, LED TV from 2011) to the ONKYO and repeated the measurements:
Noise floor raises way, way higher to -77 to -79 db:
Ugly, my friends... Clearly having the TV HDMI connected has injected very significant amount of noise in the system! Dynamic range has dropped to ~80dB across the board (equivalent to 13-bits). Notice a very strong 60Hz mains hum which is even showing up in the frequency response graph... What is happening here is that I'm seeing the effect of ground loops. There are ways to overcome this of course.
Ugly my friends!
Recall that I pointed out the same thing in my measurements. That even when using S/PDIF input, mere act of connecting the source to the HDMI processor/AVR degraded its performance. That degradation was very small but this one is massive.
So don't go celebrating that "this reviewer" said HDMI is fine. It is not fine. HDMI electrically couples of the products together, making a long chain that can suffer from ground loops and noise transmission.
Maybe where analog audio connections are concerned, but the Onkyo did not suffer the same problem when HDMI was used for audio purposes.
Originally Posted by amirm
Again, this was all on the NWAVguy's web site. So please read the information you are citing. Don't just go for headlines. If not me, there will be another double digit IQ person who would call you on lack of due diligence.
Come again. Its not me lacking dilligence, it's YOU!
Okay, in the past amir and rant bud, DonHo, have relegated me (UndersAVS) to some dude posting tidbits from the Internet trying to shout down the mighty Microsoft Exec, business owner, and degreed Engineer. How dare! No chance that UndersAVS will earn those AVS oak leaf clusters. Folks, bear with me please.
Amir points out the website's Onkyo AVR analog measurements, revealing ground loop/TV/hdmi related problems, but totally ignores the website measurement of HDMI performance with TV and Blu-ray player connected and powered-on; -108.8dB or better. Quote:
"Since I want to check the performance in a more "naturalistic" fashion, I made sure the TV was connected and on as well as my Blu-ray player (Panasonic BMP-TD220). Remember that in my previous post, plugging in the HDMI TV cable added significant noise to the analogue pass-through. All results were made with the Onkyo in "Pure Audio" mode to defeat any audio DSP/bass management."
"MEASUREMENTS: ONKYO TX-NR1009 as HDMI / SPDIF DAC... Are AV Receivers any good?"
The -78dB noise that amir mentions from the same website, but different page, is ANALOG performance, NOT HDMI PERFORMANCE, and caused by ground loop interference.
"MEASUREMENTS: Separate vs. AV Receivers (Emotiva XSP-1 vs. Denon AVR-3802 vs. Onkyo TX-NR1009) as Analogue Preamp."
The bottomline, is that hdmi performance was not degraded by the ground loop error and the noise measurement is excellent.