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Critic's Corner Discuss a review. Provide constructive feedback. Talk to the industry. |
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Critic's Corner Discuss a review. Provide constructive feedback. Talk to the industry. |
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In Reply to: Finally someone wants to try and verify some of the numbers, many of the manufacturers are quoting... posted by Ugly on October 21, 2019 at 15:59:53:
How is trying to come up with 10 or so tests to try and finally obtain an apples to apples comparison database fixating?
How would you select the tests? If they are going to be used to compare and judge audio products, they should be relevant to sonic performance. Otherwise, we're just playing with numbers.
Amir seems to like measuring DACs, and focuses a lot on THD+N/SINAD.
In fact, that is how he ranks them. But why should anybody care about THD+N for a DAC? Even comparatively poor measuring modern DACs have insignificant levels of distortion and noise that are comfortably below other sources and contribute essentially nothing to the system. Filterless DACs are an exception, but they are so "broken" there's really no point in comparing them to a standard DAC.
When questioned about the relevance of certain measurements, he always pulls out the bad engineering card. I think you know what I mean. If measurements of a product show deviation from linearity creeping up below -100 dBFS, or an FFT shows spuria at the -120 dB level when some other products keep them all below -130 dB, the manufacturer will be accused of bad engineering. AS IF it's good engineering practice to spend effort chasing numbers that don't matter.
Another issue I have with trying to use Amir's measurements to judge & rank components is that I don't see him making enough of an effort to give each product a thorough evaluation. He's busy, so he typically performs a "drive by" review and if there are problems with how he did things, or things he should have done differently specific to the DUT, their discovery happens later and its buried in the comments. The review is not updated, and the headline/conclusion and ranking remain the same.
A good example of that was the first time he measured an A/V pre-pro.
The manufacturer specified a rated output of 2.4V for the XLR outputs, and a reference output level of 2V at 0 dB volume setting. Amir missed this when he measured it. Because it's an A/V pre-pro not a DAC and he was measuring the pre-amp output, the logical thing to do would have been to measure at reference volume (0 dB). Instead, he turned it up higher to get 4V from the XLR output with a full scale input. Several pages into the comments section, when the results were cross checked with others, it became evident that exceeding the rated output was highly likely to have generated the higher distortion he measured. But by then it was too late to re-measure.
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Follow Ups
- RE: Finally someone wants to try and verify some of the numbers, many of the manufacturers are quoting... - Dave_K 14:08:19 10/22/19 (3)
- RE: Finally someone wants to try and verify some of the numbers, many of the manufacturers are quoting... - Ugly 21:45:23 10/22/19 (2)
- RE: Finally someone wants to try and verify some of the numbers, many of the manufacturers are quoting... - Dave_K 12:55:51 10/24/19 (1)
- RE: Finally someone wants to try and verify some of the numbers, many of the manufacturers are quoting... - Ugly 11:58:34 10/26/19 (0)
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