pbarach, viva wikipedia! Now please take a look FFT of 27.5Hz piano sample to find that fundamental tone there like a modulator for overtones without any noticeable SPL level ;) Simple experiment: take piano music and cut off frequencies lover 50-100Hz, check the difference vs full range, can...

Green curve is he400i, yellow my old Sennheizer, sorry, I can not read the model # of that headphone, just too old and the name 100% erased, however, its freq.resp quite similar to hd600 with rolloff lower 100Hz.

GirgleMirt, I measured my he400i (2017 version) with calibrated mic EMM-7150 but without fake Pinna nor simulated ear canal i.e. exactly the same way like diyaudioheaven https://diyaudioheaven.wordpress.com/headphones/measurements/ My frequency response is dramatically different, and close to...

"Listen to piano with minimal mics" is the wrong material to talk about "nothing really under 45 Hz". I have doubt if a piano needs freq.resp. lower than 100-50Hz, and by the way >10kHz, in other words, 100-10000Hz frequency response limitation will notice about 5-10% of listeners.

BTW, according to https://www.innerfidelity.com/images/SennheiserHD600.pdf vs https://www.innerfidelity.com/images/HiFiMANHE4002014.pdf frequency response of he400i (2014) is quite flat up to 10-20Hz but HD600 drops lower 100Hz. I measured my he400i with calibrated mic and found the same flat...

To me, ringing is the high Q resonant, he400i membrane is a thin and soft mylar film i.e. low Q and in fact, aperiodic. This is the only reason to use thin film-actuators, planar or electorstatic instead of dynamic. All resonants in such type of actuator are air standing waves related but not...

are you serious about that? I thought less output impedance is always better. Actually, in the case of planar headphone load, we can expect near perfect linear Z vs Freq., hence, the higher output impedance will mean only lower power.

I think the test is 100% wrong.. they asked for my music and I reply [jazz] [classic] but finally, I got for the test some kinda eclectic junk with tonnes of uncontrolled bass )) No idea why I got such ugly track to test, it sounds rather like anti-jazz.

Ohh, It is a hardware DSP control app, without HW connected it works in Demo-mode just for illustration. The HW is "PowerDAC V2" the true digital USB audio interface Dimensions: 75x46x19mm Weight: 70g Materials: Fine sandblasted 6063 aluminum + black anodize, polished stainless steel + laser...

CoFire, it is DSP control app, nothing more. BT Low-Energy(BLE) interface is using as a physical link to PoverDAC V2. If your smartphone(I'm sure it does) supports simultaneous work of BT streaming and BLE, then DSP control and BT stream the same time is possible. The PowerDAC V2 has BLE only...

gregorio, it is a quite old story about Mr. Putzeys, for sure it happened on diyaudio.com 2003-2004 when he tried to establish there "Switching Power Amplifiers and Power D/A conversion" forum. And finally we got that forum, OMG, it was 15 years ago...

Yes, thank planar topology but even 1% of 2nd harmonic doesn't sound as harsh distortion. The 2nd harmonic is the same as octave tones just make a sound bit more rich and complex, usually, listeners don't associate 2nd harmonic with distortions at all. PS: I've published the App officially...

HE400 should have more 2nd(pleasant one) harmonic between distortion products because of magnets applied only one side of the membrane. BTW, this is probably the main reason for quite poor sensitivity.

huh, that is the first thing what people refer when compare vinyl vs CD, especially earlier ones, when producers wanted to implement all hopes regarding new format(CD) dynamic range, and did reduce compression for that. Finally, all consumers noticed the difference LP vs CD, however, it was...

pbarach, could you please upload particular track where you feell distortions, short one? What is the amp you using? I hear no distortions in mids(piano as well good, I've Yundi plays Chopin) but can notice low-end freqs turbulence noise, probably I can try other pads if want to fix. Actually...

Oh, sorry, wrong link, the App is here https://drive.google.com/open?id=1z6Ia-rKUsStK3zJ5CzVUgFL_OMTbSE2q

gregorio, well know your precise&slow style of reply, let me ask you one more question right now.. What's your opinion about the statement of Bruno Putzeys regarding that the flat THD+N vs freq plot is the factor(one of) of sound neutrality?

I using quite normal compressor cell with no artificial coloration or so, if you wish you can take a look my Android App here https://drive.google.com/open?id=1GNMPSEoxISauSIg4YKfEDFLSfvknuu3D It can work in demo mode without HW. Only one thing there a but unusual is Energy slider which allows...

gregorio, quite accurate corrections, and I agree. Only maybe about level vs volume maximizing difference doesn't look clear, and about the power, I said that 350mW isn't enough for AC/DC drive that means peak ability(700mW), of course, AVG power I can get 2x more ;) BTW, do you think it is bad...

I specify Zout as 1.5ohm@1kHz but in fact, it is a bit lower. And again, the compressor doesn't affect THD+N of static sine if release time slow enough, anyway, for the PowerDAC which is open loop system and its THD at level .006% is considered as a great result, I can not see compressor's...

I'm talking about so-called Fully Digital "Amplifier" or Power DAC(USB->digitally modulated PWM->72 LVC gates in parallel->passive LC demodulation so no analog amplification or feedback involved) which in my case powered from 5VDC USB rail, the highest power is available in case if power...

I'm not a rock-n-roll guy at all, and I prefer Diana Krall rather than AC/DC. However, last week I prepared some DSP presets for rock-n-roll. I tried a few AC/DC hits and quickly realized that 350mW isn't really enough for my HFM HE400i to drive AC/DC pleasantly, that corresponds to about 120db...

Ideas made us a human.

castleofargh, you could be right again. These two design is completely different for topology reason, first is open loop Power DAC(PowerDAC V2 = TAS5558 I2S->PWM and lots of LVC logic gates in parallel as a PWM power stage + passive LC demodulation), the second one is conventional DAC+AMP(#9038S...

I have two HPAs, one with 1.5ohm output impedance, second with 50 mOhm, and I easily hear the difference in bass there. 1.5ohm has a bit less control but noticeable more punch vs 50mOhm. It is quite normal for the 4-8ohm speakers if less damping induces some hump on the frequency response but I...