Is Someone Playing Fast & Loose With Measurements?

[Hiro]

the difference in distortion is nearly 10 times! i.e. LH Labs measurements showed a 10 fold increase in distortion.

 

Comparing measurements made by different people (and likely in different test conditions) strikes me as rather useless.

[Hiro]

Hi,

 

 

 

Interesting take.

 

So, you go to Les 5 Saisons at Westmount, you get 500 Gram Kobe Beef.

 

When you get home, you feel something is not quite right, you weight and you find they gave your 300 Gram.

 

You go back and raise the issue, only to be told:

 

"Comparing measurements made by different people (and likely in different test conditions) is useless."

 

The point of measurements is that they SHOULD be comparable and repeatable. Otherwise they would be rather useless.

 

How did the test conditions differ when making the two measurements?

 

I don't think you have understood my point...

[Hiro]

Hiro,

 

I understood your point perfectly.

 

Two different scales were used, from different manufacturers.

 

These are not different test conditions.

 

Larry Ho provided the following additional information for his test measurements:

 

"Here is my parameters setting, I'm open for any suggestion or discuss from you or JA. ;-)

 

* Output load is not 100k Ohm or 200K, which is usually not the real headphone load situation. I set 300Ohm in Audio Precision which is more real. By this alone, THD+N will be different.

 

 

* I set the bandwidth of measurement to 90K Hz. Not traditional 20K Hz.... Why? Because since everybody is talking about the important of HD music. Why limit the measurement bandwidth to 20k here. It's proven wrong to assume people could hear only below 20KHz.

Again, this single setting will change the SNR and THD results.

 

 

* I use 'un-weighted' numbers. A lot of people they use 'A-weighted'... why? Because A-weighted numbers looks better..."

 

My point is that unless other measurements are done under the exactly same set of parameters we can't really compare them.