Why you can't trust measurements

[GoldenOne]

2 minutes ago, pkane2001 said:

 

This was brought up here before, but I'm not sure what the answer is. Are your measurements done with the same AP project settings as those that Amir is using? If not, there could be differences in settings (as per your video) that could account for some of the differences.

It depends. Amir has not shared his configuration publicly and he's hardly going to give it to me I imagine so I have no idea if it's the same or not.

 

But for the basic bench mode 1khz test where most of the settings can be pretty much assumed and the bandwidth is shown, I can match his config for that specific one. And in that situation I've had some devices which did not perform the same.

 

And to be clear that's not any 'fault' of amir. He's measuring the device given to him.

The issue is that some manufacturers may cherry pick and there is no way for amir (or viewers of his site) to know if that's happening or not

[Josh Mound]

20 minutes ago, pkane2001 said:

 

It would be unethical for him to conduct a teardown of a product that the owner doesn't want torn down :) Where permission is given, Amir usually does and posts a separate thread for these. 

I think it’s unfair to manufacturers for some, but not others, to receive that kind of scrutiny. (He’s noted that Topping, for example, gives him products for free without asking it be returned, but has not done teardowns on all of those products, so it’s clearly not solely a permission issue.) If not all people who submit products agree to teardowns, he can either not do teardowns at all or purchase units himself.

 

I’ll add that — even as a proud anti-corporate pinko who’s a big “consumer movement” Naderite — I still recognize that people’s livelihoods, no matter how big the company, are impacted by reviews. So bending over backwards to be fair to all companies only seems right to me. The zeal to try to help consumers, which I share, doesn’t obviate that.

[pkane2001]

3 minutes ago, GoldenOne said:

It depends. Amir has not shared his configuration publicly and he's hardly going to give it to me I imagine so I have no idea if it's the same or not.

 

But for the basic bench mode 1khz test where most of the settings can be pretty much assumed and the bandwidth is shown, I can match his config for that specific one. And in that situation I've had some devices which did not perform the same.

 

And to be clear that's not any 'fault' of amir. He's measuring the device given to him.

The issue is that some manufacturers may cherry pick and there is no way for amir (or viewers of his site) to know if that's happening or not

 

Yeah, the 1kHz dashboard, while revealing, isn't painting the whole picture. I much prefer sweeps with varying levels and frequency showing noise, THD/IMD, linearity. With those tests, there are some parameters that can differ significantly without being visible on the AP chart, that's why I'm asking. 

 

 

[GoldenOne]

Just now, JoshM said:

I think it’s unfair to manufacturers for some, not not others, to receive that kind of scrutiny. (He’s noted that Topping, for example, gives him products for free without asking it be returned, but has not done teardowns on all of those products, so it’s clearly not solely a permission issue.) If not all people who submit products agree to teardowns, he can either not do teardowns at all or purchase units himself.

On this note I'm quite curious to see internals of the new topping LA90.

 

Afaik topping hasn't done a discrete amp before so it'll be interesting to see what's inside this.

 

But whilst topping usually has at least partial internal views in their marketing material and full internal shots available elsewhere, there are no views of the insides available and they've seemingly asked Amir not to open it.....

 

[GoldenOne]

Just now, pkane2001 said:

 

Yeah, the 1kHz dashboard, while revealing, isn't painting the whole picture. I much prefer sweeps with varying levels and frequency showing noise, THD/IMD, linearity. With those tests, there are some parameters that can differ significantly without being visible on the AP chart, that's why I'm asking. 

 

 

There absolutely are. But unfortunately as mentioned Amir does not share his configuration publicly so there's no way to verify.

[Josh Mound]

1 minute ago, pkane2001 said:

 

Yeah, the 1kHz dashboard, while revealing, isn't painting the whole picture. I much prefer sweeps with varying levels and frequency showing noise, THD/IMD, linearity. With those tests, there are some parameters that can differ significantly without being visible on the AP chart, that's why I'm asking. 

 

 

I suspect I’ll be hitting you up for some advice on best practices using your Multitone with the Cosmos ADC. I have some vintage DACs I want to write up.

[pkane2001]

3 minutes ago, GoldenOne said:

On this note I'm quite curious to see internals of the new topping LA90.

 

Afaik topping hasn't done a discrete amp before so it'll be interesting to see what's inside this.

 

But whilst topping usually has at least partial internal views in their marketing material and full internal shots available elsewhere, there are no views of the insides available and they've seemingly asked Amir not to open it.....

 

 

Topping seems very concerned about competition copying their designs. Lately they started to scratch off all chip/component labels from every PCB before shipping. Looks kinda ugly. Wonder what they did in a discrete design LA90 to obscure it :)

 

[GoldenOne]

1 minute ago, pkane2001 said:

 

Topping seems very concerned about competition copying their designs. Lately they started to scratch off all chip/component labels from every PCB before shipping. Looks kinda ugly. Wonder what they did in a discrete design LA90 to obscure it :)

 

That's probably pretty valid tbh. 

 

I'll be getting one in soonish and will open it up to have a look. Hopefully it's not too obscured inside.

 

[fas42]

1 hour ago, pkane2001 said:

 

It's important to know what measurements are and what they are good for. Certainly, poor measurements can point to poor design and/or poor engineering. Or, they may demonstrate intentional deviation from transparency.

 

 

The severe tribalism in the audio world does no favours, for anyone. Measurements have almost no value for someone who wants to assemble a system for maximum listening satisfaction; it's become a fetish to either put numbers on a sacred altar, or treat them with contempt - the truth, as is often the case, is elsewhere .

 

It has been repeated an infinite number of times, that conventional measurements are a poor guide to a system's subjective qualities - personal experience, 35 years ago, made this obvious. Ongoing beating on the worn out drum that it's possible to assess a setup by checking each component on a testbench is getting the audio world nowhere - it's time to move to better methods ...

[pkane2001]

5 minutes ago, fas42 said:

It has been repeated an infinite number of times ... personal experience, 35 years ago, made this obvious. 

 

You're right, Frank! You've repeated this an infinite number of times 😉 

 

[opus101]

Nah its definitely only a finite number. It was only five years ago that that number he quoted was 30.

[fas42]

Gosh, you just reminded me ... 30 years ago, I said to someone, 5 ...

[pkane2001]

5 hours ago, opus101 said:

Nah its definitely only a finite number. It was only five years ago that that number he quoted was 30.

You’ll need to account for the number of messages per year, month, week, day, hour, second, millisecond, etc. As far as infinities go, what we're dealing with here might be one of those larger, uncountable infinities, as per Georg Cantor :)

[fas42]

Yes, I'm aiming for a googolplex - at least ...

[yamamoto2002]

6 hours ago, fas42 said:

Yes, I'm aiming for a googolplex - at least ...

 

It seems relatively small number of bits are needed to express 1 googolplex with PCM digital 🙂

 

33219280948873623478703194294893901758648313930245806120547563958159347766086252158501397433593701550996573718 + 1 bit (extra one bit is for sign bit)

 

BTW number of atoms of the earth is approx. 10^49 to 10^50, so it is not possible to build the storage to store this data.

 

 

 

 

[yamamoto2002]

I looked into further and now I think symbolic math approach is better to accommodate such a big numbers, i.e. 1 googolplex is expressed as a string of "10^{10^{100}}" as a sampled value of PCM: On this approach, 1 googolplex number occupies only 13 bytes on the storage, and much larger values than 1 googolplex can be expressed (Fig.1). Furthermore, there is no quantization error on rational, irrational and complex numbers such as "{-1+i√3)/2" which is e^{i*π/3} = cos(π/3) + i*sin(π/3) because there is no quantization performed, and any sinusoidal waves can be expressed mathematically exact.

 

Fig.1

[pkane2001]

8 hours ago, yamamoto2002 said:

 

It seems relatively small number of bits are needed to express 1 googolplex with PCM digital 🙂

 

33219280948873623478703194294893901758648313930245806120547563958159347766086252158501397433593701550996573718 + 1 bit (extra one bit is for sign bit)

 

BTW number of atoms of the earth is approx. 10^49 to 10^50, so it is not possible to build the storage to store this data.

 

 

 

 

Now we just need to ask the developer of the AS forum software to increase the number of bits used to store the message counter.  Just in case the storage capabilities catch up in the near future:)

[botrytis]

1 hour ago, pkane2001 said:

Now we just need to ask the developer of the AS forum software to increase the number of bits used to store the message counter.  Just in case the storage capabilities catch up in the near future:)

 

OH, come on now. Not that bad......

 

100 TB SSD Price

 

NOT THAT BAD 🤣

[Windows X]

You already know measurement is the best selling point for budget product. And people who can buy only budget gears need to convince themselves they buy best bang of the buck product having measurements superior to more expensive product. If you try to crash their foundation of their belief, they will treat your content as heresay.

 

From my years long debate with such people, it's better to leave them alone in their comfort zone. They will never change their mindset until they're rich enough to afford better things. Truth is it's never about objective VS subjective but rich VS poor under audio terminology. Just enjoy with what you have and people can be happy with different things.

[Samuel T Cogley]

Ah yes.  The predictable "Objectivists are envious peasants" trope.  Where have I seen that before? 🙂

 

Oh, and I think the word you're looking for is heresy, not "heresay" [sic].

 

 

[botrytis]

On 5/12/2022 at 1:06 AM, Windows X said:

You already know measurement is the best selling point for budget product. And people who can buy only budget gears need to convince themselves they buy best bang of the buck product having measurements superior to more expensive product. If you try to crash their foundation of their belief, they will treat your content as heresay.

 

From my years long debate with such people, it's better to leave them alone in their comfort zone. They will never change their mindset until they're rich enough to afford better things. Truth is it's never about objective VS subjective but rich VS poor under audio terminology. Just enjoy with what you have and people can be happy with different things.

 

What nonsense.

 

Some people react, others care not one wit.

 

Use what you like. I don't judge. I mean a Yugo gets you to the same place as does a Brand-new Ferrari. They both get the job done.

 

I still believe, one needs both measurements and listening. W/O that it is too much decision making based on emotion.

[Windows X]

14 hours ago, botrytis said:

 

What nonsense.

 

Some people react, others care not one wit.

 

Use what you like. I don't judge. I mean a Yugo gets you to the same place as does a Brand-new Ferrari. They both get the job done.

 

I still believe, one needs both measurements and listening. W/O that it is too much decision making based on emotion.

 

Nonsense? I saw a lot of objectivists who's been through exactly like I said. Some even told me his regrets. I also believe there's audiophiles using both objective and subjective data to make decision. But budget gear's best selling point is still about measurements. That's the only thing you can claim you're doing this better than more expensive things "objectively". ;)

[botrytis]

5 hours ago, Windows X said:

 

Nonsense? I saw a lot of objectivists who's been through exactly like I said. Some even told me his regrets. I also believe there's audiophiles using both objective and subjective data to make decision. But budget gear's best selling point is still about measurements. That's the only thing you can claim you're doing this better than more expensive things "objectively". ;)

 

Really - one needs both. One cannot make an honest opinion without objective measurements. Subjective data means nothing, because so many of the reviewers are older than me and have worse ears than me. I cannot use their ears and have their background which affect how they hear things. Subjective data is NEVER used in science as it is hard to prove a negative.

 

My wife and I just bought a new piece of equipment, based on measurements and then a trial in our home. The dealer was great, and he basically said, take it home and listen, if it is not an immediate difference bring it back. 

[Samuel T Cogley]

8 hours ago, Windows X said:

 

Nonsense? I saw a lot of objectivists who's been through exactly like I said. Some even told me his regrets. I also believe there's audiophiles using both objective and subjective data to make decision. But budget gear's best selling point is still about measurements. That's the only thing you can claim you're doing this better than more expensive things "objectively". ;)

 

So once objectivists get some money, they're not objectivists anymore???? 🤔

 

[Windows X]

37 minutes ago, Samuel T Cogley said:

 

So once objectivists get some money, they're not objectivists anymore???? 🤔

 

 

They're still objectivists but they probably realize something and stop making comments they used to perhaps. I haven't seen any highend objectivists besides me here too. If there's there any objectivist who uses $30k CD Player or Transport + DAC at least, please say hi. I miss you guys. Thanks.

 

Regards,

Keetakawee