There is no contract of any sort. They made the offer to me to re-test everything I had reviewed with fresh, newly bought units. They made that offer because unethical people like you spreading untrue rumors. For that reason, I saw no reason to make them incur such a cost. It is easier to just debunk your random assertions and use that limited resource to test more products.
Are you still making those dangerous audio products Mike? Last I heard you had closed shop and left customers abandoned with unsafe and non-working amps and such.
No, that is not right. I do a ton of listening tests as part of my reviews.
That aside, I can run 100 measurements if I wanted as some people do. In doing so though, I would lose 90% of the audience. As such, it is critical that we use a core set of tests that are sufficient to characterize the level of excellence in engineering of a product.
The tests I ran already had a 32-tone test to cover full frequency range:
We can already see the slight rise in distortion with frequency. I don't know what you get out of running the same test but with only two tones.
Time to do some homework.No, that is not right. I do a ton of listening tests as part of my reviews.
That aside, I can run 100 measurements if I wanted as some people do. In doing so though, I would lose 90% of the audience. As such, it is critical that we use a core set of tests that are sufficient to characterize the level of excellence in engineering of a product.
The tests I ran already had a 32-tone test to cover full frequency range:
We can already see the slight rise in distortion with frequency. I don't know what you get out of running the same test but with only two tones.
https://www.ap.com/technical-library/more-about-imd/
Because the stimulus tones are high in frequency, CCIF is a useful measurement for observing distortion in devices that exhibit distortion that rises with frequency. Since the tones by default are only 80 Hz apart, much of the energy contained in the distortion products will fall near or below the stimulus tones. This makes CCIF a good choice for measuring distortion at higher frequencies in band limited devices, where harmonic distortion products from high-frequency stimulus tones would fall
out of band.
“In some applications, like production testing, a small number of tones is sufficient to catch manufacturing defects, and an excessive amount of data collection and detail isn’t desired. Additionally, the more tones you add together, the lower each one needs to be to keep the overall level the same, and this can lead to less accuracy in the distortion and noise measurements. But, 32 tones is great for a detailed frequency response graph. So, it’s a choice of what’s most important to you.”
https://www.ap.com/technical-library/multitone-analysis-with-apx500/
https://www.ap.com/technical-library/multitone-analysis-with-apx500/
A matter of
, and they do sound better than a pair of NCore channels (I don't own Purifi and most likely will never want to). It is impossible to match Purifi's efficiency in Class AB and it is expensive to match Purifi's high power (you need to parallel output devices in Class AB, among other things), but then at home you don't need more than a few dozen watts (in case the link doesn't work properly, see post #467 in that thread). On the other hand, matching Purifi's performance in Class D requires solving some rather involved math problems, and Bruno Putzeys and the team to cut through them .BTW, this Hypex white paper has a very nice explanation of why IMD measurement are useful, how they complement THD measurements, plus a couple of other things.
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I have no problems with ASR test. Though the ranking at 5W at 4ohm will make other amps struggle with the "Noise" part so the tendency is to make the input sensitivity / gain low (I myself guilty of it with Sylph-d200).
Because of the ranking system, future amps will just focus on designing amps with massive feedback since they can profit more on the score ranking instead of making amps with excellent and robust build quality.
Let's admit it, ASR is now slowly gaining influence and authority in the audio industry.
Maybe there is a need on re-ranking with normalized values based on input sensitivity / amplifier gain. And ranking based on other parameters like distortion, IMD etc.. New ways on how data is presented, so that we will not concentrate on a single SINAD score
Because of the ranking system, future amps will just focus on designing amps with massive feedback since they can profit more on the score ranking instead of making amps with excellent and robust build quality.
Let's admit it, ASR is now slowly gaining influence and authority in the audio industry.
Maybe there is a need on re-ranking with normalized values based on input sensitivity / amplifier gain. And ranking based on other parameters like distortion, IMD etc.. New ways on how data is presented, so that we will not concentrate on a single SINAD score
But quite some of them seem to be mono sessions - no? And your listening efforts are hardly "scientific", are they? Level control, same room, same tracks, fidelity (you seem to play mostly studio/artificial music form UT?) and do you optimise according to each producers positioning recommendation? I would stick to pure measurement and include some very hard ones so that the bar is still something for everyone to aim for. I think the site is generally fine but please consider the problems with KPIs - they will always be miss-used in some sense and one seldom get what one hoped for if they are not very well thought out. I do lack some way to explore the dynamic behaviour of amps in both freq. and time domain.
32 tone test is good. Maybe the situation with the higher levels as in a 2 or 3 tone test can show different aspects of the DUT.
Do you publish a with paper on your measurement strategy and what it is aimed to show? This would be interesting to read.
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Wow, ASR wars ..... Huh.
@amirmaj , in the twin tone CCIF tests, 19+20kHz (most often) or 18+20kHz or 18.5+19.5kHz or 18+19kHz are used. I think the reason of lower than 20kHz 2nd frequency is only the usual visualization in 20Hz - 20kHz band. Sometimes 13+14kHz or 10+11kHz tones are used, but it does not make much sense. 19+20kHz indicates to beginning of slew induced distortion, as well, and of course to HF nonlinearity.
@amirmaj , in the twin tone CCIF tests, 19+20kHz (most often) or 18+20kHz or 18.5+19.5kHz or 18+19kHz are used. I think the reason of lower than 20kHz 2nd frequency is only the usual visualization in 20Hz - 20kHz band. Sometimes 13+14kHz or 10+11kHz tones are used, but it does not make much sense. 19+20kHz indicates to beginning of slew induced distortion, as well, and of course to HF nonlinearity.
However I am not the one to be addressed by your post, I am not arguing with the war actors here.
Yes I agree, as long as a moderator should move it to another forum section and anyway with the diversion of the subject which has turned into a small war between the one who has the biggest car.
I suggest to use really simple sentences and words in its own native language if communicating via a translator. Your messages often come out really "special".
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