Radsone EarStudio ES100
Mar 5, 2018 at 6:51 AM Post #301 of 6,390

PiSkyHiFi

100+ Head-Fier
Joined
Dec 15, 2009
Posts
273
Likes
152
I gather you're detailing how SBC and APT-X can have their flaws revealed - can you offer a comparison of other implementations of Aptx and SBC that have a better spec list to reveal that the ES100 is different ?

I haven't noticed any issues with SBC, other than the quality is overall less than AptX HD.

Just putting on Miles trumpet in Kind of Blue's Blue in Green reveals the issues with SBC... ringing tones can be heard easily.


Also, please graph AAC, this is a pretty good codec imo, how does it stack up against the others?
 
Last edited by a moderator:
Mar 5, 2018 at 7:14 AM Post #302 of 6,390

SubMash

100+ Head-Fier
Joined
Mar 4, 2018
Posts
294
Likes
120
Location
Prague
I don't have same problems with any other SBC or APTX transmitters. But I will test now more. AAC with Beats have abosolutely no aliasing or clipping or any other audible harmonics to me. My VW stereo SBC has very tiny aliasing and no clipping.

I do not believe clipping is part of APTX. I do not believe such heavy aliasing is solely SBC either.

Could you guys graph aptx-hd already? App is readily available and it's 2 minute test. Thanks.
 
Mar 5, 2018 at 8:07 AM Post #303 of 6,390

p50kombi

Head-Fier
Joined
Jan 15, 2018
Posts
64
Likes
81
Location
UK
I don't have same problems with any other SBC or APTX transmitters. But I will test now more. AAC with Beats have abosolutely no aliasing or clipping or any other audible harmonics to me. My VW stereo SBC has very tiny aliasing and no clipping.

I do not believe clipping is part of APTX. I do not believe such heavy aliasing is solely SBC either.

Could you guys graph aptx-hd already? App is readily available and it's 2 minute test. Thanks.


Well, at least you're not impatient or your posts don't come across as demanding...that's a plus :wink:
 
Last edited:
Mar 5, 2018 at 9:36 AM Post #305 of 6,390

SubMash

100+ Head-Fier
Joined
Mar 4, 2018
Posts
294
Likes
120
Location
Prague
So second series of test.

What if the problem is only due to low Ohm earbuds (Shure SE846 is 9Ohm).
Or what if that noise is codec only?

Let's compare it to 20$ 6 years old Nokia APTX transmitter.
https://www.ebay.com/itm/Nokia-MD-2...HROMECAST-CAST-AUDIO-MUSIC-WIFI-/272949648938

This is Spectral recording on 24 bit 192kHz 113dB SNR line input. 17.4kHz sine tone.
Left to right: EarStudio SBC, EarStudio APTX, Nokia APTX, Nokia SBC
Ear_Studio_vs_Nokia_on_20k_Ohm_Line_In.png


Nokia is a bit louder, but not enough to invalidate results.
Nokia doesn't have aliasing at all.
APTX obviously noisy with both of them. But if you hear sound from both - it's night and day.
I will do recording later - logarythmic spectral doesn't give it justice...

It's obvious that with lower load harmonics decreasing significantly.
But it's still there - it's the same 8kHz at extremely low load which should never be an issue for an amplifier.

I'm going to do more tests.

More of tests - now comparison of Nokia APTX and EarStudio sweeps. What if test is irrelevant and issue only happens at high frequency? Here is full sine sweep 20KHz-20Hz. Guess who is who. Again - NO LOAD.
Nokia_Sweep_APTX.png

Ear_Studio_Sweep_APTX.png
 
Last edited by a moderator:
Mar 5, 2018 at 10:01 AM Post #307 of 6,390

SubMash

100+ Head-Fier
Joined
Mar 4, 2018
Posts
294
Likes
120
Location
Prague
What are your settings during the test?
DCT level?
DAC Filter?
HD Jitter Cleaner?
I can promise you that I've tried all settings - the only thing that changes the picture is codec switch SBC/APTX. APTX introduces heavy clipping noise but has same harmonics.

Those tests made with Jitter Cleaner ON, 2x Current Unbalanced out, no EQ obviously, DCT OFF, Short Delay Slow Roll-Off filter, 4x oversampling. But, again, I tried to change them all - no perceivable difference for those issues.
 
Mar 5, 2018 at 10:08 AM Post #308 of 6,390

scotvl

100+ Head-Fier
Joined
Feb 22, 2016
Posts
310
Likes
221
So second series of test.

What if the problem is only due to low Ohm earbuds (Shure SE846 is 9Ohm).
Or what if that noise is codec only?

Let's compare it to 20$ 6 years old Nokia APTX transmitter.
https://www.ebay.com/itm/Nokia-MD-2...HROMECAST-CAST-AUDIO-MUSIC-WIFI-/272949648938

This is Spectral recording on 24 bit 192kHz 113dB SNR line input. 17.4kHz sine tone.
Left to right: Nokia SBC, Nokia APTX, EarStudio APTX, EarStudio SBC
Ear_Studio_vs_Nokia_on_20k_Ohm_Line_In.png


Nokia is a bit louder, but not enough to invalidate results.
Nokia doesn't have aliasing at all.
APTX obviously noisy with both of them. But if you hear sound from both - it's night and day.
I will do recording later - logarythmic spectral doesn't give it justice...

It's obvious that with lower load harmonics decreasing significantly.
But it's still there - it's the same 8kHz at extremely low load which should never be an issue for an amplifier.

I'm going to do more tests.

Sometimes two devices just don't have great synergy together, do you have another aptx or aptx hd source you can try? Have you tried the double current option for the 3.5mm output in the app? Wslee posted that lower impedance earphones would greatly benefit from this option. My ES100 is on the way so I can't test it yet but all of the reviews I've read here and elsewhere say it sounds amazing so I hope it's something you can figure out maybe 2.4 GHz wifi interfering with the ES100 somehow?


https://www.amazon.com/gp/aw/reviews/B078H4YD2L/ref=cm_cr_dp_mb_top?ie=UTF8
 
Last edited:
Mar 5, 2018 at 10:09 AM Post #309 of 6,390

meinname123

New Head-Fier
Joined
Dec 18, 2017
Posts
40
Likes
21
Location
Germany
I can promise you that I've tried all settings - the only thing that changes the picture is codec switch SBC/APTX. APTX introduces heavy clipping noise but has same harmonics.

Those tests made with Jitter Cleaner ON, 2x Current Unbalanced out, no EQ obviously, DCT OFF, Short Delay Slow Roll-Off filter, 4x oversampling. But, again, I tried to change them all - no perceivable difference for those issues.
Ah, ok.
 
Last edited:
Mar 5, 2018 at 10:40 AM Post #310 of 6,390

scotvl

100+ Head-Fier
Joined
Feb 22, 2016
Posts
310
Likes
221
So second series of test.

What if the problem is only due to low Ohm earbuds (Shure SE846 is 9Ohm).
Or what if that noise is codec only?

Let's compare it to 20$ 6 years old Nokia APTX transmitter.
https://www.ebay.com/itm/Nokia-MD-2...HROMECAST-CAST-AUDIO-MUSIC-WIFI-/272949648938

This is Spectral recording on 24 bit 192kHz 113dB SNR line input. 17.4kHz sine tone.
Left to right: EarStudio SBC, EarStudio APTX, Nokia APTX, Nokia SBC
Ear_Studio_vs_Nokia_on_20k_Ohm_Line_In.png


Nokia is a bit louder, but not enough to invalidate results.
Nokia doesn't have aliasing at all.
APTX obviously noisy with both of them. But if you hear sound from both - it's night and day.
I will do recording later - logarythmic spectral doesn't give it justice...

It's obvious that with lower load harmonics decreasing significantly.
But it's still there - it's the same 8kHz at extremely low load which should never be an issue for an amplifier.

I'm going to do more tests.


Maybe you are right and it could be the low impedance of the 846s combined with the output of the ES100. The iBasso IT01s I will primarily be using with the ES100 are 16 ohm so I hope they sound great together.

http://nwavguy.blogspot.ca/2011/02/headphone-amp-impedance.html?m=1

THE FREQUENCY RESPONSE PROBLEM: If the output impedance is more more than 1/8th the headphone impedance there will be variations in the frequency response. With some headphones, especially balanced armature or multi driver designs, these variations can be rather extreme. Here’s what 43 ohms of output impedance does to the Ultimate Ears SuperFi 5’s frequency response—a total, and very audible, variation of 12 dB:
 
Mar 5, 2018 at 10:50 AM Post #311 of 6,390

veraideishal

New Head-Fier
Joined
Mar 26, 2016
Posts
48
Likes
38
More of tests - now comparison of Nokia APTX and EarStudio sweeps. What if test is irrelevant and issue only happens at high frequency? Here is full sine sweep 20KHz-20Hz. Guess who is who. Again - NO LOAD.
Nokia_Sweep_APTX.png

Ear_Studio_Sweep_APTX.png

These results are very interesting; I like looking at measurement data. :)

If we were to look at the block diagram provided by Radsone, we may be able to narrow down the possible source of these artifacts:

Capture.PNG


Working backwards from the Sound Output stage, you say that the output has no load on it (by which I assume you mean it is connected to a high-impedance Line In device and nothing else), so it's probably not the Analog Gain Control (i.e. the PGA and headphone amp) that is saturating and distorting.
(For those who are speculating that it's a problem with damping factor aka impedance mismatch, I would like to clarify that damping factor changes the frequency response but does not introduce new frequencies that were not originally present, and especially not over such a large frequency range. New frequencies created == nonlinear distortion.)
You say that AAC does not appear to have artifacts (do you have any plots to show this?), so it probably isn't the D/A Conversion stage (which includes the DAC's antialiasing and oversampling settings) consistently outputting wrong analog voltages in response to the digital PCM input.

Has the Digital Gain Control (which is probably also where Radsone's proprietary DSP such as Jitter Cleaner, DCT lives) been set at 0dB, so no truncation error can result?
Perhaps Jitter Cleaner may introduce artifacts when it re-clocks the decoded PCM?
If not, by process of elimination, it leaves the Decoder stage for SBC and aptX as the possible culprit on the Sink (i.e. the Earstudio) end.

Going further backwards to the Source device, we can probably rule out the Encoder stage, since as you say you've tried several sources
The Digital Gain Control of the source may be a factor (again, due to truncation error); are the source volumes also set to maximum?
 
Last edited:
Mar 5, 2018 at 10:52 AM Post #312 of 6,390

SubMash

100+ Head-Fier
Joined
Mar 4, 2018
Posts
294
Likes
120
Location
Prague
Sometimes two devices just don't have great synergy together, do you have another aptx or aptx hd source you can try? Have you tried the double current option for the 3.5mm output in the app? Wslee posted that lower impedance earphones would greatly benefit from this option. My ES100 is on the way so I can't test it yet but all of the reviews I've read here and elsewhere say it sounds amazing so I hope it's something you can figure out maybe 2.4 GHz wifi interfering with the ES100 somehow?


https://www.amazon.com/gp/aw/reviews/B078H4YD2L/ref=cm_cr_dp_mb_top?ie=UTF8
1. Yes, I've tried MacBook Pro instead of Samsung S8+ - exactly same sound.
2. Yes, I'm testing everything on double current option - that was the whole point of buying it.
3. I've tried single current also - no difference.
4. No it's not interference - it's stable intermodulation harmonics or aliasing. Clipping also consistently depend from tone frequency.

Maybe you are right and it could be the low impedance of the 846s combined with the output of the ES100. The iBasso IT01s I will primarily be using with the ES100 are 16 ohm so I hope they sound great together.

http://nwavguy.blogspot.ca/2011/02/headphone-amp-impedance.html?m=1

THE FREQUENCY RESPONSE PROBLEM: If the output impedance is more more than 1/8th the headphone impedance there will be variations in the frequency response. With some headphones, especially balanced armature or multi driver designs, these variations can be rather extreme. Here’s what 43 ohms of output impedance does to the Ultimate Ears SuperFi 5’s frequency response—a total, and very audible, variation of 12 dB:

Second test was to check if low impedance is an issue - NO. I put it to >20kOhm line input - strong aliasing - tests above are all without any load. So it's not the reason.
 
Last edited by a moderator:
Mar 5, 2018 at 10:58 AM Post #313 of 6,390

scotvl

100+ Head-Fier
Joined
Feb 22, 2016
Posts
310
Likes
221
1. Yes, I've tried MacBook Pro instead of Samsung S8+ - exactly same sound.
2. Yes, I'm testing everything on double current option - that was the whole point of buying it.
3. I've tried single current also - no difference.
4. No it's not interference - it's stable intermodulation harmonics or aliasing. Clipping also consistently depend from tone frequency.
Just trying to help, it sucks when you order something then wait for it while you read how others are enjoying it and when it arrives you have problems with it. Good luck and I hope you are able to return them if you can't find a fix.
 
Mar 5, 2018 at 11:05 AM Post #314 of 6,390

SubMash

100+ Head-Fier
Joined
Mar 4, 2018
Posts
294
Likes
120
Location
Prague
These results are very interesting; I like looking at measurement data. :)

If we were to look at the block diagram provided by Radsone, we may be able to narrow down the possible source of these artifacts:

Working backwards from the Sound Output stage, you say that the output has no load on it (by which I assume you mean it is connected to a high-impedance Line In device and nothing else), so it's probably not the Analog Gain Control (i.e. the PGA and headphone amp) that is saturating and distorting.
(For the rest who are speculating that it's a problem with damping factor aka impedance mismatch, I would like to point out that damping factor changes the frequency response but does not introduce new frequencies that were not originally present, and especially not over such a large frequency range.)
You say that AAC does not appear to have artifacts (do you have any plots to show this?), so it probably isn't the D/A Conversion stage (which includes the DAC's antialiasing and oversampling settings) consistently outputting wrong analog voltages in response to the digital PCM input.

Has the Digital Gain Control (which is probably also where Radsone's proprietary DSP such as Jitter Cleaner, DCT lives) been set at 0dB, so no truncation error can result?
Perhaps Jitter Cleaner may introduce artifacts when it re-clocks the decoded PCM?
If not, by process of elimination, it leaves the Decoder stage for SBC and aptX as the possible culprit on the Sink (i.e. the Earstudio) end.

Going further backwards to the Source device, we can probably rule out the Encoder stage, since as you say you've tried several sources
The Digital Gain Control of the source may be a factor (again, due to truncation error); are the source volumes also set to maximum?

I need to repeat AAC test yet - still doing RMAA on Nokia for reference.

Digital volume was set to 0dB, for sure - that was first question support has asked me and I studied docs well before using it. I tried to change all settings - nothing removes clipping or aliasing. Now I have to say - APTX on Nokia also sandy, BUT it's so low level that I have to crank up the volume really high. While on EarStudio it's extremely loud.

I have 2$ USB sound card - it also has aliasing doesn't matter which signal or what setting are sent - I assume it's frequency conversion with bad rounding.

We already eliminated source - Nokia on exactly same source doesn't make any aliasing and clipping is way below the level of importance.
 
Mar 5, 2018 at 11:09 AM Post #315 of 6,390

SubMash

100+ Head-Fier
Joined
Mar 4, 2018
Posts
294
Likes
120
Location
Prague
Just trying to help, it sucks when you order something then wait for it while you read how others are enjoying it and when it arrives you have problems with it. Good luck and I hope you are able to return them if you can't find a fix.
I don't really care that much about returning. I can afford to lose 300$ without ruining my mood. It's a Kickstarter purchase - it's meant to support new companies that propose good ideas. But I thought I would help guys to find and fix a problem and found out that they don't care?... So I assume some people here might care still and somebody could be really frustrated in mine place.

I still would like to hear feedback from WS...
 

Users who are viewing this thread

Top