[james444]

I don't have the time to read the whole context, but when conducting those IEM "burn-in" tests, have you allowed for letting the tips within the coupler to settle after a sufficient amount of time without playing any signals to see if the changes were due to small movements of the IEM within the coupler amid longer-term material compression or stretching? Could you compare the results of conducting the usual test both with and without any burn-in signals playing between measurements?

Good question! As for the comparison between "with and without burn-in signals playing between measurements": no, I haven't done that. Because it would require two brand new identical IEMs, which I simply didn't have at hand. However, I never used the supplied original tips for these "burn-in" tests, but picked particularly soft silicone third party tips instead, that have proven to give me reliable coupler seal and consistent results across a large number of measurements. Therefore, I think it's unlikely that changes in tips or fit played any role, although you're right that only a comparative test could answer that question once and for all.

 

[Ryokan]

Silicone tips benefit from warming up.

 

[james444]

Silicone tips benefit from warming up.

In which way? I'm not aware of any benefits apart from them maybe becoming more flexible and easier to get a seal with.

 

[Ryokan]

In which way? I'm not aware of any benefits apart from them maybe becoming more flexible and easier to get a seal with.

Better seal, better sound.

 

[james444]

Better seal, better sound.

Strictly speaking, there is no "better" seal. Tips either seal or leak. There are varying degrees of leakage though, that's true.

(In IEM measurements, you'd see distinct bass roll-off if the tips didn't seal. In the graphs I posted, there's no roll-off down to 20Hz.)

 

[taffy2207]

My Dinner benefitted from a burn in period of 30 minutes. There was a definite improvement in texture and taste of said food, but I did hear some noticeable sibilance from my food at around the 20 minute mark.

No further tests were carried out as the evidence was munched furiously.

 

[Syan25]

The best burn in happened when I set my ears aflame. After about 20m, I had no ears remaining. So it really doesn't take days...

 

[Ryokan]

Cables sound the same, burn in not a thing. You guys'll be telling me there's no Santa next

 

[KinGensai]

Cables sound the same, burn in not a thing. You guys'll be telling me there's no Santa next

Who's gonna pop that bubble I wonder lol

 

[Syan25]

Just enjoy the sound you've got - or buy different equipment. I wouldn't rely on anything but your own hearing.

 

[castleofargh]

I wouldn't rely on anything but your own hearing.

Everybody wants that, no matter the side of the argument. The difference comes with how to handle the fact that human experience is more than just listening. Some embrace it all, they accept that whatever influences will happen and just go with the flow (what I would call a real subjectivist). Some try to remove the non-listening elements to make their decisions only on what they hear. That's what I often try to do, and I believe it is the closest thing there is to "just listen". And some just pretend like they're living gods, always right, perfect memory from the sound 2 months ago, perfect control over biases.

 

[mbphotox]

okay...

Resolve is a big name among headphone users.. And he's convinced that ESS sounds different from Burr Brown DACs..

He did a somewhat lame blind test (for a guy with tens of thousands at his disposal..) and got basically everything right..

https://forum.headphones.com/t/blind-testing-source-equipment-the-limits-of-discernibility/6204


What should we think of this?

What do you tell someone who's like: "Resolve did it, it's so easy. If your ears aren't crap, everyone can do it, 100% success rate."



Should'nt you be able to just feed the signal through a DAC and back into the computer and compare what you get from "different" DACs on a spectrum?

 

[MrHaelscheir]

Should'nt you be able to just feed the signal through a DAC and back into the computer and compare what you get from "different" DACs on a spectrum?

For this, I think you can look up what people have found for DAC and amp "null testing". I think https://www.audiosciencereview.com/...-error-metric-discussion-and-beta-test.19841/ was the latest development for that on ASR, but I still need to do more reading. I would be more interested in software that could plot any spectral differences with respect to time for two chains playing the same music through the same transducer. Else taking the difference between the signals and analyzing them for audibility would suffice.

As for Resolve, others may be better at explaining the details of what may have been wrong with the test and what additional controls were needed.

Now, one thing that I am personally not clear with yet is the relation of the DAC linearity measurement to the DAC's magnitude and phase response which if different from flat would constitute "linear distortions". But I suppose that the multitone distortion measurements for different DACs already show pretty dead flat responses for the respective tones.

 

[VNandor]

I would be more interested in software that could plot any spectral differences with respect to time for two chains playing the same music through the same transducer.

Unless I misunderstand you, deltawave (the software you linked) can already kinda do that. It can give you the difference of spectrum as well the difference of amplitudes over time. If you want a graph that shows spectrum over time on a 2D plot, just load the difference file produced by deltawave into a spectrogram maybe. You could use a real time spectrum analyzer as well if you are OK with time being represented actually over time instead of on the X axis.

 

[Ryokan]

Strictly speaking, there is no "better" seal. Tips either seal or leak. There are varying degrees of leakage though, that's true.

(In IEM measurements, you'd see distinct bass roll-off if the tips didn't seal. In the graphs I posted, there's no roll-off down to 20Hz.)

It's much harder getting a good seal in the human ear compared to a measuring device with a uniform receptacle. Adding it all up there are just too many variables with our anatomy to conclude sound change is simply down to burn in I guess.