Have you checked - Audio level setting for playback. In Loopback all FFT softwares do not Control RTX. Some do and causes the output to lower level. Make Playback to Maximum for your loopback. It takes some time to understand how one software works as the documentation lacks such details.
Yes, it is important to state also the switch settings when doing measurements, since dBFS in itself is not the whole story. The units are calibrated, so the conversion is relatively straight forward, but I realize that it is easy to get the scales wrong.
I hope that, going forward, there will be support in some analyzer SW packages for automatic conversion. The switch settings are availvable on the USB interface (HID) and with this information it will be possible to scale the voltages in the program, thereby avoiding the manual conversion from dBFS to dBV, dBu or whatever is preferred.
The information about whether the unbalanced or the balanced output is used would have to be entered by the user though, since there is no way to get that information from the analyzer. The 6 dB difference can lead to confusion if not accounted for.
It would be great if analyzer SW like HpW Works, MATAA, audioTester, ARTA etc. would get built-in support for it. But this is not under my control in any way.
I hope that, going forward, there will be support in some analyzer SW packages for automatic conversion. The switch settings are availvable on the USB interface (HID) and with this information it will be possible to scale the voltages in the program, thereby avoiding the manual conversion from dBFS to dBV, dBu or whatever is preferred.
The information about whether the unbalanced or the balanced output is used would have to be entered by the user though, since there is no way to get that information from the analyzer. The 6 dB difference can lead to confusion if not accounted for.
It would be great if analyzer SW like HpW Works, MATAA, audioTester, ARTA etc. would get built-in support for it. But this is not under my control in any way.
zfe,
You seem to be missing the content.
Assume the RTX6001 to be perfect and will never require calibration.
It is the Software that requires calibration or programing for each selector switch position.
For switch position 1; 0dBFS equals 100Vrms
For switch position 2; 0dBFS equals 31.6Vrms
For switch position 3; 0dBFS equals 10Vrms
For switch position 4; 0dBFS equals 3.16Vrms
For switch position 5; 0dBFS equals 1.00Vrms
For switch position 6; 0dBFS equals 0.316Vrms
For switch position 7; 0dBFS equals 0.100Vrms
Without knowing the attenuator switch position 0dBFS could mean any of 7 possibilities.
Many audio analyzers are auto ranging, The RTX6001 requires manual range adjustments by the operator.
Also the 6dB difference between balanced and unbalanced needs to be accounted for.
I am still in the process of setting up the RTX6001 on my bench. In the process I will fill in a spread sheet for the special numbers for each switch position for audio Tester V3 and post it here for inclusion in the wiki if there is interest.
To include all the autorange pieces parts would push the price point beyond reach.
JensH thanks for your time and effort producing the RTX6001. A first class machine.
DT
You seem to be missing the content.
Assume the RTX6001 to be perfect and will never require calibration.
It is the Software that requires calibration or programing for each selector switch position.
For switch position 1; 0dBFS equals 100Vrms
For switch position 2; 0dBFS equals 31.6Vrms
For switch position 3; 0dBFS equals 10Vrms
For switch position 4; 0dBFS equals 3.16Vrms
For switch position 5; 0dBFS equals 1.00Vrms
For switch position 6; 0dBFS equals 0.316Vrms
For switch position 7; 0dBFS equals 0.100Vrms
Without knowing the attenuator switch position 0dBFS could mean any of 7 possibilities.
Many audio analyzers are auto ranging, The RTX6001 requires manual range adjustments by the operator.
Also the 6dB difference between balanced and unbalanced needs to be accounted for.
I am still in the process of setting up the RTX6001 on my bench. In the process I will fill in a spread sheet for the special numbers for each switch position for audio Tester V3 and post it here for inclusion in the wiki if there is interest.
To include all the autorange pieces parts would push the price point beyond reach.
JensH thanks for your time and effort producing the RTX6001. A first class machine.
DT
Sure! It would be cool if were not the only one adding content to the WIKI page.
I'd suggest to keep details to software-specific configuration related to the RTX in a separate section. I added a new section (2.3) for this.
Apart from the two extremal cases you mentioned, it is good to know where FS is located on your scale, as about 10dB below you get the best performance (distortion or noise wise) - which is e.g. important if you have a very low noise DUT.
At least I have a better feeling in terms of dBFS on where the ADC noise floor is located - which is important to know if you want to know if the noise floor you see is from the ADC of the DUT.
I know for the DiAna, Edmond 🙂
Wow! I didn't know that the asio4all have such capabilities!
Thanks, nyt!
Wow! I didn't know that the asio4all have such capabilities!
Thanks, nyt!
It can be ... finicky... but it works in a pinch. That's what I used to measure the Motu into the RTX.
Yeah, I had seen your measurement with Motu at the REW but I don't immagine that this was with asio4all.
Very useful information, my congrats.
Just, complete some dac measurements with RTX on a dac via asio4all.
Very useful information, my congrats.
Just, complete some dac measurements with RTX on a dac via asio4all.
This is a sample “calibrated” balanced plot scaled in dBV.
The output switch is in the center position 1 volt, -20dBFS is selected in the steup options.
The input switch is in position #6, -10, 0.316.
Select options from the menu, click calibration and enter 316.22 mv and enter.
Sample size is 192K. 10 averages.
The computer is gen. 8, I7 8700k coffee lake.
This RTX 6001 rocks.
DT
The output switch is in the center position 1 volt, -20dBFS is selected in the steup options.
The input switch is in position #6, -10, 0.316.
Select options from the menu, click calibration and enter 316.22 mv and enter.
Sample size is 192K. 10 averages.
The computer is gen. 8, I7 8700k coffee lake.
This RTX 6001 rocks.
DT
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That's impressive! I actually didn't believe that mine is as good as this, so I repeated the loopback test with your settings. Wow, mine is the same!
(I should stop drooling over loopback results and get some real work done...)
Attachments
Hi mbrennwa,
As far as I understand you are using your own sw tool? If so, it shouldn't be to hard to get access to the HID interface on the RTX using libusb and possibly python.
I really wish there were a good tool that run on Linux.
My RTX 6001 is still in the box, as I haven't had time to look at it, so I haven't tried to access the HID interface.
Mogens
As far as I understand you are using your own sw tool? If so, it shouldn't be to hard to get access to the HID interface on the RTX using libusb and possibly python.
I really wish there were a good tool that run on Linux.
My RTX 6001 is still in the box, as I haven't had time to look at it, so I haven't tried to access the HID interface.
Mogens
