Similar sensitivity, Way different perceived loudness?

[frimincoffee]

Hello.

I did some trial and error to match loudness of headphone with Peace(Equalizer APO) preamp

by
1. Using can's sensitivity(db/1Vrms) spectification and headphone power calculator.
2. Preamp to match my SPL target
3. Adjust non-preamp-ed volume to match my SPL target

It is not accurate, but I'm pretty satisfied what I did.

But when I try the same thing with IEM that I did with headphone,
its sound way louder so I had to adjust preamp setting by add -6db.
I know my dac/amp do not have some kind of high/low gain caused by impedance of can.


It really not a problem but this experience got me thinking

: With my short-knowledge speculation, the 'sensitivity' means how much SPL driver can make with 1 Volt.
Then what I should do with the differences of headphone and IEM to get similar loudness level I perceive?
Is this all about how driver close to eardrum?

 

[staticV3]

sound pressure level due to sensitivity or open (closed) back characteristics?

Hi, I’m new to this field. I just used a mobile player to drive one open back hp (sensitivity = 103dB) and one closed back one (sensitivity = 98dB) in SE mode. I found out with the same volume configuration the open back hp creates a much weaker sound pressure level. Is this due to sensitivity...

www.audiosciencereview.com

 

[frimincoffee]

sound pressure level due to sensitivity or open (closed) back characteristics?

Hi, I’m new to this field. I just used a mobile player to drive one open back hp (sensitivity = 103dB) and one closed back one (sensitivity = 98dB) in SE mode. I found out with the same volume configuration the open back hp creates a much weaker sound pressure level. Is this due to sensitivity...

www.audiosciencereview.com

So my thought about sensitivity was wrong!
Then why I had such a noticable difference? Because the manufacturer are different?
By the way I did some test with Sennheiser HD560s(110db/V) and 7hz Salnote Zero(108db/V)

edit : I'm terribly sorry, my dac/amp has some of output power change when impedance is different.

 

[DVDdoug]

If the measurements are done on the same set-up they should be comparable. Measuring SPL output from a headphone isn't as straightforward or reliable as something like a voltage measurement so I'd expect some differences with different manufacturers. Even the same manufacturer might use a different setup with headphones & IEMs.

And sensitivity is usually measured at 1kHz so frequency response differences can make a difference with music or other program material.

I know my dac/amp do not have some kind of high/low gain caused by impedence of can.

It's possible for a low impedance load to "drag down" the voltage making it lower than "expected". But usually it's the IEMs that are lower impedance so they would be quieter than expected.

 

[frimincoffee]

It's possible for a low impedance load to "drag down" the voltage making it lower than "expected". But usually it's the IEMs that are lower impedance so they would be quieter than expected.

Thanks. In this case IEM was louder, guess it is a measurement difference and I have to adjust by my ear.