Bass control differences between DAC? What to check with measurements?

[Pdxwayne]

How did you adapt RCA to the Solo's balanced input? Monoprice RCA --> XLR cable? You may want to temporarily resort to battery operation on the laptop in order to defeat any ground loop issues.

I think Audacity uses WASAPI by default these days, but it's shared mode and as such settings for the recording device have to be explicitly chosen (the control panel dialog has gotten even more hidden since Windows 10 but is still there). Format might default to 16/44 for all I know.

In the CS4272's ADC as used in this device, digital filter stopband at single speed starts at about 0.58fs, so you really want to run that at 48 kHz at least (no aliasing until 0.42fs = 20.2 kHz). I would recommend 96 kHz (stopband from 0.68fs --> no aliasing until 0.32fs = 30.7 kHz). 192 kHz probably is diminishing returns territory (stopband from 0.78fs --> 0.22fs = 42.2 kHz, though ultimate rejection is a few dB better still).

BTW, in controlled listening tests level matching to 0.1 dB is advised. 0.3 dB is about the limit of human perception. A mismatch of 0.5 dB probably won't cut it.

I see. I will use 96KHz to capture and see how it is.

I was using the right channel of Scarlett Solo today when using Reaper and got very bad loopback noise (noisy even when laptop in battery mode). I switched to left channel, using RCA to XLR adapter from DAC, then it is a lot quieter.

Yeah, the E30 is about 0.7db louder than X16 when using same db setting on each DAC. So, even if I adjusted E30 db 0.5db lower, it is still about 0.2db louder.

Thanks!

 

[Blumlein 88]

Only suggestion I have left is try 96 khz. And you shouldn't need to do so. Oh and try another track of music that has response into the higher frequencies. And maybe look at how your cables run. Are the signal carrying cables close to a PS block or something like that. If you can run the signal carrying cables so they close to nothing except the device on each end.

 

[Blumlein 88]

Do a short track of some silence and one with a -60 db 1 khz tone. And let us see the spectrum of that in Deltawave. Use a little over 30 seconds. Will let us see if you have some steady noise somewhere.

 

[Pdxwayne]

Only suggestion I have left is try 96 khz. And you shouldn't need to do so. Oh and try another track of music that has response into the higher frequencies. And maybe look at how your cables run. Are the signal carrying cables close to a PS block or something like that. If you can run the signal carrying cables so they close to nothing except the device on each end.

I have been placing my laptop on top of my large 15" sealed sub.... Could it cause interference?

 

[Blumlein 88]

I have been placing my laptop on top of my large 15" sealed sub.... Could it cause interference?

Subs typically have class D amps or switched power supplies so that is quite possible.

 

[Pdxwayne]

Subs typically have class D amps or switched power supplies so that is quite possible.

And my RCA cable is between the large sub and my power conditioner....

OK. I will remove my DAC away from my stereo setup and just check on a table next.
: )

 

[Pdxwayne]

Do a short track of some silence and one with a -60 db 1 khz tone. And let us see the spectrum of that in Deltawave. Use a little over 30 seconds. Will let us see if you have some steady noise somewhere.

Simple 30 seconds 1 Khz tone captured twice with x16 seems to show simple tone is doing ok.

Matched spectra:

Delta of spectra of 1Khz tone (1 Khz looks fine)

However, when comparing music, even capture same music twice on X16, they don't really match in the high freq, but seems good enough with variants of 0.2db up to around 20Khz?

Using 96khz to compare e30 and x16, it would seems the high frequencies differences up to 20Khz would not be audible. So it would seems my observation of high freq differences might not be valid.

Anyway, even moving my chain away from subwoofer and power conditional, my chain still have a little noise in the high freq, but not sure which one is the culprit. : (

Thanks for all the tips!

 

[Blumlein 88]

Actually most of these look improved when you take into account the different scaling on the db side. It isn't uncommon if playing 44.a files and recording at 96 khz the above 20 khz has lots of noise in it.

Now for instance where you capture the X16 twice that looks pretty good. If you use a LP filter in Deltawave with that set at 20 khz you'll get likely an even lower null and it is already pretty darn good at near -90 db. And that one didn't seem much effected by below 20 khz noise. Just a little bit more than maybe I'd expect.

Well sorry I didn't foresee some of these issues in the way, but on the bright side you've learned a bit about how to do this. I certainly wish I'd remembered to warn you about recording directly to Audacity. Audacity is a terrific free bit of software unfortunately it does have a few hidden gotchas.

 

[Pdxwayne]

Actually most of these look improved when you take into account the different scaling on the db side. It isn't uncommon if playing 44.a files and recording at 96 khz the above 20 khz has lots of noise in it.

Now for instance where you capture the X16 twice that looks pretty good. If you use a LP filter in Deltawave with that set at 20 khz you'll get likely an even lower null and it is already pretty darn good at near -90 db. And that one didn't seem much effected by below 20 khz noise. Just a little bit more than maybe I'd expect.

Well sorry I didn't foresee some of these issues in the way, but on the bright side you've learned a bit about how to do this. I certainly wish I'd remembered to warn you about recording directly to Audacity. Audacity is a terrific free bit of software unfortunately it does have a few hidden gotchas.

I found Audacity easier to use than Reaper. So I use Reaper to record and Audacity to cut the recorded file to proper length.
: )

I appreciate all the tips. I am happy to learn about all these free softwares.

 

[Pdxwayne]

The high frequencies noise in my previous measurements seems to be related to using Node2i Coaxial out.

Using USB out directly from laptop to DAC, using a full song from another artist, E30 vs X16 matched pretty much perfectly up to 20Khz.

 

[Pdxwayne]

Same song as the one above, using USB in. Anything to learn from the phase diff between E30 and X16?

 

[Pdxwayne]

Anyone here knows how to interpret Phase Delta and Group Delay? Thanks!

Using same 15 seconds bagpipe high notes song, here is the Phase Delta between DAC, using Coaxial and Optical:


Phase delta between DAC using Coaxial:

Phase delta between DAC using Optical:

 

[Pdxwayne]

Anyone here knows how to interpret Phase Delta and Group Delay? Thanks!

Using same 15 seconds bagpipe high notes song, here is the Phase Delta between DAC, using Coaxial and Optical:


Phase delta between DAC using Coaxial:
View attachment 113984

Phase delta between DAC using Optical:
View attachment 113986

I was told by Deltawave developer that the phase diff for the bagpipes notes is nothing to concern about. So we are good.

 

[Pdxwayne]

Now I realize why I said X16 is significantly better in bass when I first compared to E30 using headphone setup. At that time I was listening with CD quality music via Tidal.

This is a very strange thing. When playing back Tidal Master in 96Khz today, I noticed that they are about the same loudness when E30 volume is set at -15.5db and X16 volume is set at -15db. According to DeltaWave app, E30 is about 0.2db louder when set volume that way.

However, when playing back CD quality music (44.1Khz) via Tidal via USB to E30 vs X16, X16 is significantly louder than E30 (when everything set the same as before when listening to 96Khz music). DeltaWave can't even compare the captured music as the dB difference is too large! X16 is 12db louder when playing back Tidal's CD quality music!

Here is the DeltaWave message:

DeltaWave v1.0.61, 2021-02-21T17:25:28.1327114-08:00
Reference: e30_ella_minus_first_song_30seconds_e30_minus15.5_solo_in_Reaper_96khz_32_bit_left_channel_usb_in.wav[L] 2880000 samples 96000Hz 32bits, stereo, MD5=00
Comparison: x16_ella_minus_first_song_30seconds_x16_minus15_solo_in_Reaper_96khz_32_bit_left_channel_usb_in.wav[L] 2880000 samples 96000Hz 32bits, stereo, MD5=00
Settings:
Gain:True, Remove DC:True
Non-linear Gain EQ:False Non-linear Phase EQ: False
EQ FFT Size:65536, EQ Frequency Cut: 0Hz - 0Hz, EQ Threshold: -160dB
Correct Drift:True, Precision:30, Subsample Align:True
Non-Linear drift Correction:False
Upsample:False, Window:Hann
Spectrum Window:Hann, Spectrum Size:32768
Spectrogram Window:Hann, Spectrogram Size:4096, Spectrogram Steps:2048
Dither:False
Trim Silence:False
Enable Simple Waveform Measurement: False

Discarding Reference: Start=0s, End=0s
Discarding Comparison: Start=0s, End=0s

Initial peak values Reference: -17.84dB Comparison: -5.864dB
Initial RMS values Reference: -29.106dB Comparison: -17.119dB

Null Depth=4.264dB

X-Correlation offset: -57 samples
Stopped! One or more errors occurred.
Signature: 7e6c0dc9dba58ed6b0e6fcaa6983c8c4


The track in question:

 

[Pdxwayne]

I am concluding this thread with my findings:

That bass issue is specific to Tidal app issue on Windows. Somehow when using forced volume mode, it forced down volume for e30. Turn off forced volume, then manually set everything to max, then it is OK. However, if I touch the volume slider inside Tidal app, like slide it down and then to max, Windows volume control would auto adjust down E30 volume. Very odd.