Radsone EarStudio ES100
Mar 5, 2018 at 11:19 AM Post #316 of 6,390

veraideishal

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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.

I think the problem with the USB sound card is different from the problem with the Earstudio. On the USB sound card, it takes in uncompressed PCM data and outputs a voltage. If there is any aliasing, it's due to only that process (PCM to voltage, possibly due to bad rounding and a lousy anti-aliasing filter).

With the Earstudio, if AAC (and the USB DAC output, if that gets tested) show no problems, then it is not the PCM to voltage conversion that is to blame (testing the USB DAC mode of the Earstudio is probably the best way to confirm this, since it is taking in PCM data directly).
The problem then lies with the Decoder, which takes in either compressed SBC and aptX and converts to PCM. There is likely to be more problems that result from the decompression process.

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...

WS is probably asleep; it's the middle of the night in Korea.
 
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Mar 5, 2018 at 11:28 AM Post #317 of 6,390

SubMash

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I think the problem with the USB sound card is different from the problem with the Earstudio. On the USB sound card, it takes in uncompressed PCM data and outputs a voltage. If there is any aliasing, it's due to only that process (PCM to voltage, possibly due to bad rounding and a lousy anti-aliasing filter).

With the Earstudio, if AAC (and the USB DAC output, if that gets tested) show no problems, then it is not the PCM to voltage conversion that is to blame (testing the USB DAC mode of the Earstudio is probably the best way to confirm this, since it is taking in PCM data directly).
The problem then lies with the Decoder, which takes in either compressed SBC and aptX and converts to PCM. There is likely to be more problems that result from the decompression process.

WS is probably asleep; it's the middle of the night in Korea.
I still need to test AAC properly. I don't remember now. I will test USB DAC also for sure.
 
Mar 5, 2018 at 11:28 AM Post #318 of 6,390

antdroid

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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...

I cant try out your test right now. I have pretty weak LTE coverage at my office and also the phone mic picks up a ton of ambient noise. I dont know how accurate it would be.

That said, are you hearing audible issues using apt-x with actual music/videos or just the test?

I just listened to a couple songs and switched back and forth between SBC, AAC, Apt-X and AptX HD and i dont hear any clipping or any issues of note.
 
Mar 5, 2018 at 12:08 PM Post #319 of 6,390

SubMash

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I cant try out your test right now. I have pretty weak LTE coverage at my office and also the phone mic picks up a ton of ambient noise. I dont know how accurate it would be.

That said, are you hearing audible issues using apt-x with actual music/videos or just the test?

I just listened to a couple songs and switched back and forth between SBC, AAC, Apt-X and AptX HD and i dont hear any clipping or any issues of note.
Ambient noise doesn't matter - if headphone will be at the microphone - it will overpower everything - you can see signal pattern.
I started searching for the issue with Lana Del Rey and Soulsavers songs - on a high pitch clean tones I can clearly hear clipping.
Btw, since I have 3 devices - I've tried them all.
 
Mar 5, 2018 at 12:10 PM Post #320 of 6,390

SubMash

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Some update - I tried AAC from iPhone X. RMAA for it is really bad. And, btw, I found out RMAA doesn't catch this issue well - I will post it later. But - there is NO aliasing or clipping on AAC on EarStudio although sound is not very sharp (and RMAA confirms it), but it's consistent. Look at those. So issue is with SBC/APTX encoders.

Ear_Studio_Sweep_AAC.png


Compare it with APTX on EarStudio:
Ear_Studio_Sweep_APTX.png


And here is AAC 17.4kHz tone - a lot of smooth harmonics.
Ear_Studio_Tone_AAC.png


Still need to finish USB DAC
 
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Mar 5, 2018 at 12:41 PM Post #321 of 6,390

SubMash

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USB DAC can't test today - there is -70dBA Noise Level which obviously is a ground loop.
Ear_Studio_Noise_Level_Modes.png

I need to think how to remove it tomorrow. It's midnight for me as well.

I also probably need to redo the whole RMAA - it was on the 10kHz limit for THD.
 
Mar 5, 2018 at 6:21 PM Post #322 of 6,390

RobinFood

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Is there a way to get an earstudio in Japan? Amazon US and Canada won't ship here, and I can't find any resellers on ebay or aliexpress either.

I need some kind of clip-on with bluetooth for my er4 when commuting, and was thinking of this as a solution that can keep the sound quality and let me take out the PtoS adapter.
 
Mar 6, 2018 at 1:10 AM Post #324 of 6,390

wslee

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All,

I'd like to share some ES100 data measured using Audio Precision 2722 right next to my desk.

[Test condition]
- ES100 3.5mm output
- No load
- EQ, DCT off
- AK4375a / sharp roll-off / 1x

aptX (with Galaxy S8 source device)
upload_2018-3-6_14-58-38.png


It's just a lossy waveform codec using no psychoacoustic model.
It uses QMF(Quadrature mirror filter) to split the input into a certain number of sub bands.
And then it encodes each sub band with the limited bit allocation;
more bits in the lower frequency band, less bit in the higher frequency band.

SBC(SubBand Codec) also split the input into sub bands, but it allocates the same number of bits per for all sub bands.
That's the one of the main difference between SBC and aptX.

SBC is a very simple codec with low complexity.
The low complexity nature was the primary reason for having SBC as mandate Bluetooth A2DP codec.

And CSR released the new codec aptX with the key idea of allocating the different number of bits per each subband;
more bits in the lower frequency band, less bit in the higher frequency band.

So typical frequency response of a single tone would be as above.
The noise floor is not flat across frequency ranges because the quantization noise from aptX codec loss makes the floor.
aptX-HD performs better but the frequency response is similar to aptX classic.

AAC (with iOS)
upload_2018-3-6_14-58-58.png


It's a complicated codec based on the psychoacoustic model.
As you see below, the 1KHz and 10KHz tone is not sharp but shaped like a tower or triangle.
The key idea of the psychoacoustic model is that;
the signal or noise below the shape(i.e., Masking Curve) is not audible and not critical.
Eventually we just need to allocate as less bit as possible for the target signal below the masking curve.

So, the codec like AAC using the psychoacoustic model requires frequency analysis, the masking curve calculation for the time-varying input continuously,
which cost a lot of processing power and power consumption.

Since it's not a waveform coder, measuring THD+N for the signal through AAC codec has no meaning.
Only perceptual domain performance would make sense.
Anyway, AAC is more complicated than mp3, showing the better perceptual performance than mp3 at the same bit rate.

USB (lossless, with iMAC USB)
upload_2018-3-6_14-59-26.png


It shows the baseline performance of ES100 HW.
Unfortunately, ES100 USB supports 16-bit only, the overall THD+N is limited by the 16-bit PCM (-96dB), not by H/W.

Please take a look at them all above.
You will find there's no such a design flaw or HW defect as SubMash insist.

If ES100 have any H/W issue, all the BT codecs, and USB would result in the same defect.
Because all of them use the same H/W resource including DSP, DAC, and Power.
SubMash mentioned AAC & USB sounds OK.
Then it's not an H/W issue.

And if we have the problem with aptX,
how could we have ES100 in the Qualcomm's official aptX product list?
They have their own qualification and certification process for aptX enabled products.
We sent ES100 to them for their testing and finally had ours on the list.

https://www.aptx.com/products/radsone-earstudio-es100-bluetooth-receiver-headphone-amplifier

Lastly, I just took a look at the SubMash test results and graphs from his mobile phone screenshot.
It seems that he ran the test with his mobile phone.
Anyway, as I see them, those results are showing the tremendous and unacceptable noise.
If those graphs are indeed real and represent ES100 output,
the sound would be considerably worse than the expected,
and everyone would definitely notice the defect right at the start.

We can't deceive many thousands of ES100 users.
The users are not fools and would notice the that much of conspicuous defect very easily.

Thanks and Regards,
WS
 
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Mar 6, 2018 at 2:08 AM Post #325 of 6,390

myusernameislove

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Anyone used it with aptx except me? Because I can't be alone who can hear those problems.

http://www.audiocheck.net/audiotests_aliasing.php

Try this and tell me you don't hear random clicking and sand noise together with heavy harmonics ringing and sweep tones going all wrong directions. My test show harmonics louder than tone on SBC and APTX. Hope it's firmware bug - it sounds like wrong frequency conversion..

I tried it with my Sony xPeria XZ1 BT5 smartphone and Audio Technica AT-PHA55BT receiver with SBC, AAC, Aptx, LDAC support (no AptxHD), and LDAC, AAC, SBC is fine, but with Aptx I hear some sand.

edit/ I also tried my phone with Inateck BR1006 receiver with SBC, AAC, Aptx, AptxHD. SBC and AAC is fine, but with Aptx and AptxHD I hear some sand again.

There is two times longer sand noise with Aptx then with AptxHD on Inateck. The length of sand noise with Aptx on Inateck and on AT is about the same. The sand noise appears twice (two peaks) at higher end of the spectrum.

I have also heard one or two clicks with both units and all codecs (even LDAC) but after I repeated the test the click was gone, so I guess it is OK. Yes, I tested LDAC in all priority modes.
 
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Mar 6, 2018 at 2:33 AM Post #326 of 6,390

SubMash

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I tried it with my Sony xPeria XZ1 BT5 smartphone and Audio Technica AT-PHA55BT receiver with SBC, AAC, Aptx, LDAC support (no AptxHD), and LDAC, AAC, SBC is fine, but with Aptx I hear sand.

edit/ I also tried my phone with Inateck BR1006 receiver with SBC, AAC, Aptx, AptxHD. SBC and AAC is fine, but with Aptx and AptxHD I hear sand.

There is two times longer sand noise with Aptx then with AptxHD on Intaeck. The length of sand noise with Aptx on Inateck and on AT is about the same. The sand noise appears twice (two peaks) at higher end of the spectrum.

I have also heard one or two clicks with both units and all codecs (even LDAC) but after I repeated the test the clicks stopped occuring, so I guess it is OK. Yes, I tested LDAC in all priority modes.
So problem not only sand. It plays in the beginning sound that is NOT the tone itself, but harmonics at the lower frequency instead. And you can understand it, because tone should go linearly down and if instead it's moving up/down or doing steps - it's not the tone you hear - it's garbage.
I can confirm that sand is everywhere, but with EarStudio it's way stronger - I have a suspicion that load + oversampling influences noise. I need to check it again.
 
Mar 6, 2018 at 2:34 AM Post #327 of 6,390

tim0chan

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Using the es100 now, no issues with noise etc. With aptxhd it sounds better than with my LG g6 with quad dac
 
Mar 6, 2018 at 2:36 AM Post #328 of 6,390

wslee

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I tried it with my Sony xPeria XZ1 BT5 smartphone and Audio Technica AT-PHA55BT receiver with SBC, AAC, Aptx, LDAC support (no AptxHD), and LDAC, AAC, SBC is fine, but with Aptx I hear some sand.

edit/ I also tried my phone with Inateck BR1006 receiver with SBC, AAC, Aptx, AptxHD. SBC and AAC is fine, but with Aptx and AptxHD I hear some sand again.

There is two times longer sand noise with Aptx then with AptxHD on Inateck. The length of sand noise with Aptx on Inateck and on AT is about the same. The sand noise appears twice (two peaks) at higher end of the spectrum.

I have also heard one or two clicks with both units and all codecs (even LDAC) but after I repeated the test the click was gone, so I guess it is OK. Yes, I tested LDAC in all priority modes.

@myusernameislove:
Can I ask the sand noise you're experience is with the test tones or sweeping chirp?
Just want to check if you hear the noise only with the test signal or also with regular music sources.
Thanks and Regards,
WS
 

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