2019年12月17日 · THD+N is the inverse of SINAD in that it is the sum of all spectral components of the test tone (excluding the test tone itself) over a certain bandwidth. The voltage and level of the test tone and a greater or narrower bandwith (e.g., 4V, …

2019年11月24日 · Here are accuphase measurements LINK The THD+N graph at 0.1w show much much low levels and Signal to noise ratio is written as (1W A weighted) as 85dB all good. But here is budget Denon amplifier LINK. This Denon graph starts at 0.1 watt much higher level but the signal to noise ratio is tiny bit better at 87dB ? How come this anomaly ?

2017年9月15日 · Calculated THD for 300 Hz both numeric display and point on graph 4. Calculated THD+N for 300 Hz, numeric display and point on graph 5. 60 Hz mains noise at -90 dBu 6. 180 Hz mains noise at -105 dBu THD adds the dB levels of 2nd and higher harmonics of the fundamental input sinusoid found in the FFT, and compares the result to the fundamental ...

2019年8月29日 · THD+N (SINAD) = ratio of signal tone to everything else, noise and distortion. For example, for a 1 kHz tone, the amplitude of the 1 kHz signal to the complex or root-square-sum (RSS) of all the other frequencies' amplitudes from the FFT.

2018年11月6日 · In order to get the highest possible S/N ratio one has to play the headphone loud. For most dynamics there is a maximum power rating or linear excursion is limited. This is because one wants a high efficiency. When one could measure at 120dB it would be easier to get a higher S/N ratio.

2018年11月22日 · The processing gain can be calculated by the formula 10*log10(N/2) where N is the length of the FFT. The FFT length of Amir's dashboard is 32k (32768) so the processing gain is 10*log10(32768/2)=42 dB which means that the actual noise floor of the device is 42 dB higher than what it appears to be in the FFT.

2020年10月21日 · Rather ridiculous when viewed in context of considerably more data. THD+N vs frequency provides much more information. Additionally, 2nd, 3rd harmonics and 4+HD+N are also plotted. 4+HD+N is THD+N with 2nd and 3rd harmonics removed. Note how the THD+N and D2 lines overlap for much of the graph. THD+N for this amplifier is 2nd harmonic dominant.

2019年2月23日 · My intention is to show how wider bandwidth is reflected in THD and THD+N vs. power measurements. As a DUT, my PMA-NC252MP amplifier built with Hypex NC252MP module is used. The amplifier is in class I safety class device, with 3-wire mains cord using L, N and PE conductors.

2017年4月30日 · THD is usually no more than about 0.05% at full output which is about 20 volts. Line stage input impedance: 200 Kohm balanced, 100Kohm single ended Output imprdance: 250 Ohms from 2Hz to 400KHz Phono stage input impedance: 47 K ohms adjustable My amplifier - Benchmark AHB2 1kHz <0.0003% THD+N THD+N: 1kHz, 80kHz LPF, <-118dB (<0.00013%)

2019年2月23日 · THD+N = 0.00089% (20 - 20000Hz unweighted) makes 101dB SINAD, at THD = 0.00035% (valid just for the measurement, may differ with warm-up). I think the loop SINAD 101dB cannot be beaten by finding the "sweet spot". Anyway, There are also plots of THD and THD+N vs. level in post #1. THD/level shows some interesting inflection.