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

blanc

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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 or open (closed) back characteristics? Am I going to ge the same phenomenon with a balanced cable (I don’t have one yet)?
 

MaxwellsEq

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I don't think it's possible to answer this without knowing more facts. For example, is one pair high impedance and the other low impedance and what are the characteristics of the amplifier?
 

DVDdoug

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Of course, the more sensitive headphone should be louder. But you can't always trust the manufacturer's specs. ;)

Maybe one is rated in Volts/millivolts and the other in Watts/milliwatts?

Balanced/unbalanced doesn't make any difference in sensitivity but most balanced outputs put-out twice the voltage (+6dB) in balanced mode.
 
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blanc

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I was talking about open-back Ananda and closed-back Sundara. I don’t remember the player. It’s not mine, but a conventional portable hardware media player.
 

staticV3

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I found out with the same volume configuration the open back hp creates a much weaker sound pressure level. Is this due to sensitivity or open (closed) back characteristics? I was talking about open-back Ananda and closed-back Sundara.
Sensitivity already takes the headphone construction (open/closed) into consideration.
Most likely, HiFiMan's official sensitivity specs are simply not indicative of retail units. They're very unreliable when it comes to their sensitivity and impedance specs.

We already know how the Ananda performs from 3rd party testers:
Screenshot 2022-10-26 185809.pngThe Sundara Closed however is pretty new on the market and so hasn't been tested by 3rd parties yet.
Based on your report I'd expect it to have either a higher sensitivity (dB/Vrms), or a higher impedance (Ω), or both.
 
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blanc

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I think sensitivity is only one side. A portion of acoustic energy is going to be radiated outside of the open-back hp so the volume should be increased to get the same sound pressure as closed-back ones.
 

staticV3

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When manufacturers or 3rd party testers like Amir measure sensitivity, they only measure the acoustic energy that reaches the ear/microphone.
Not the total acoustic energy radiating from the headphone.
So no, you don't have to compensate for that.
 

Curvature

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Frequency response has to be accounted. I assume that OP did not measure SPL but is only reporting what he heard.
 

staticV3

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@blanc SoundStageNetwork has measured both the Ananda and Sundara Closed. If you convert their numbers to dB/Vrms, then you get:

Ananda: 108.5dB/Vrms
Sundara Closed: 110.2dB/Vrms

So there's your answer. At the same Amp volume, the Sundara Closed is louder than the Ananda, not because it is closed-back, but simply because it is more sensitive.
 
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