Looking for Reliable HDMI --> COAX/SPDIF Converter

[tmike]

I was actaully wanting to try that next to measure the room SINAD. But for the various equipment you would need a recording interface like a Focusrite Scarlett Solo/2i2 or I'm using a Topping E2x2.

 

[staticV3]

Thanks for sharing. Curious I have REW / Umik Microphone can I measure SINAD for the different devices I have?

You can certainly measure room SINAD with the UMIK-1, but that mic has very high self noise which will likely mask any component differences upstream.

If you want to measure the TV's digital output with different hardware configurations, then best to get a HiFime UR23.

 

[rimmi2002]

You can certainly measure room SINAD with the UMIK-1, but that mic has very high self noise which will likely mask any component differences upstream.

If you want to measure the TV's digital output with different hardware configurations, then best to get a HiFime UR23.

Thanks, for now I'll just measure the whole system and see if there is any difference between HDMI to digital audio converters....would you be able to share any instructions or perhaps an online tutorital on how to check SINAD with REW/uMIK? Thanks.

 

[staticV3]

would you be able to share any instructions or perhaps an online tutorital on how to check SINAD with REW/uMIK? Thanks.

Plug in the UMIK, open REW, and go to Preferences->Soundcard.

Choose Driver type: Java and select the EXCL versions of your DAC and UMIK in the drop-down list.

Open the Generator and RTA window.

In RTA, click the Cogwheel then:

Mode: Spectrum
No smoothing
64k FFT Length
Averages: none
Window: Hann
Max Overlap: 93%

In the Distortion settings:
Use high pass: 20Hz
Use low pass: 20,000Hz
Use AES17 Standard notch: On
Show distortion in dB

Back in the RTA window in the top left corner, set the y axis to dBc and click on Show distortion.

In the Generator, choose Tones->Sine->1000Hz.
Add Dither according to the output but depth of your DAC (REW will report the input and output bit depth on the bottom edge of the main REW window
Set output to either L or R to get a cleaner signal.

If you can control volume on your DAC directly, then you can set the REW generator to -1dBFS, otherwise set it to something lower.

When you're done, click on the green Play button in the Generator, then the red Record button in the RTA.

When the FFT has stabilized, click the red Record button again to stop the recording, then the Play button to stop playback.

In the bottom edge of the RTA window, turn off Peak then on top click Save current to save the measurement and/or click the camera icon top left to export the graph.

Before exporting, click on "20 .. 20k" in the bottom right corner, then on the Limit icon next to the Cogwheel top right, then "Match y to data".

That will center the FFT nicely.

 

[rimmi2002]

Plug in the UMIK, open REW, and go to Preferences->Soundcard.

Choose Driver type: Java and select the EXCL versions of your DAC and UMIK in the drop-down list.

Open the Generator and RTA window.

In RTA, click the Cogwheel then:

Mode: Spectrum
No smoothing
64k FFT Length
Averages: none
Window: Hann
Max Overlap: 93%

In the Distortion settings:
Use high pass: 20Hz
Use low pass: 20,000Hz
Use AES17 Standard notch: On
Show distortion in dB

Back in the RTA window in the top left corner, set the y axis to dBc and click on Show distortion.

In the Generator, choose Tones->Sine->1000Hz.
Add Dither according to the output but depth of your DAC (REW will report the input and output bit depth on the bottom edge of the main REW window
Set output to either L or R to get a cleaner signal.

If you can control volume on your DAC directly, then you can set the REW generator to -1dBFS, otherwise set it to something lower.

When you're done, click on the green Play button in the Generator, then the red Record button in the RTA.

When the FFT has stabilized, click the red Record button again to stop the recording, then the Play button to stop playback.

In the bottom edge of the RTA window, turn off Peak then on top click Save current to save the measurement and/or click the camera icon top left to export the graph.

Before exporting, click on "20 .. 20k" in the bottom right corner, then on the Limit icon next to the Cogwheel top right, then "Match y to data".

That will center the FFT nicely.

Thanks this is awesome! Really appreciate you taking the time and writing out all the steps. Will try it out this weekend and post results for the different adapters.

 

[rimmi2002]

Here is the info for SINAD for whole system MiniPC --> Tested Device --> Anthem STR Preamp --> Buckeye Purifi6525SA --> Speakers

Devices:

1. OREI DA-41 Digital Audio Converter added downstream of HD Fury 4K:
2. Amazon HDMI to digital Audio Coverter
3. OREI HDA 912 Converter (they were all about the same, I went with this one, since it supports HDCP 2.2 / HDR10+)
4. Direct USB connection from MiniPC to STR AMP (kind did it as a control, but it performed the poorest on 2/3rd harmonic)

 

[staticV3]

As expected, the UMIK's high self-noise masks any differences.

The small variations you see, are likely caused by the differences in level.

E.g. the lowest playback level also has the lowest SNR and vice versa.