- Mar 26, 2016
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.