Your Hearing and You

Interesting, I'll calculate mine later, thanks!
 

There are a couple of things that don't make sense to me.

For example he's saying that the headphone drivers are in parallel. That's not the case, there's usually a single driver per channel.

Then he's saying 10% volume corresponds to a gain of 0.1 which is just a measly -20 dB.

His power formula also seems off.

It's actually quite simple:

P = V * V / R

Let's say the ipod is set to max volume and output 1 V into the headphones which have 32 ohms nominal impedance.

P = 1 * 1 / 32 = 0.03125 watts = about 31 mW

Let's say the headphones have 100 dB @ 1 mW efficiency. To get the SPL:

Sensitivity + 10 * log10(P/0.001) = 100 + 10*log10(0.03125 / 0.001) = 115 dB SPL.

This is with full-scale sine waves of course. For rock music you can subtract about 12 dB (-> 103 dB SPL), compressed metal about the half (-> 109 dB SPL).

I used the guy´s program to automatically calculate my listening,level. On my Sennheiser HD 598's 50-ohm impedance and 112 dB SPL (which I assume is the sensitivity) and at half the iPod Touch's volume (level I usually listen to) I get 86 dB, which is kinda loud. But I assume it will also depend on each song's "innate volume" level, some songs are naturally louder than others at the same volume level.

Thanks for this thread.
 

Yes, HD598's sensitivity is 112 dB SPL @ 1 V, that is about 99 dB SPL @ 1 mW.

Could you check if the tool outputs about 112 dB SPL at full volume with your HD's?

Quote:

Originally Posted by samandhi 

  I found this an interesting read, and there is a decent app that will calculate listening levels to give you and idea of the level at which you listen to your music (I realize there are other variables involved though, like the level at which your music was recored at, and etc... that are not accounted for). http://www.ifans.com/forums/threads/estimating-headphone-volume.364522/

 

  Protect your hearing!

The biggest problem with his method is the assumption that the iPod volume control is a linear attenuator.  It isn't, and no volume control is. The assumption that a 50% position setting is half the output voltage is completely wrong, it's more like around 15dB of attenuation, just under .2 volts.  The calculation as it stands would be way off, the results would be artificially and significantly high.  The level at which music is recorded is a huge variable also, and there's no accounting for a volume normalizer like Sound Check.  

The best way to do this is to actually measure the voltage across your headphone with an RMS meter using the music in question, then back into the actual SPL based on the efficiency calculations.  In fact, if you're using an iDevice, or a Clip which has a fairly low output Z, you probably can come close enough just measuring the output voltage without headphones at all.  

I just got 101dB... i'm ****ed.... lmao

I listen to my ipod nano 6th generation at around 70-80% with HD 558's. I thought maybe the openness would be more safer then a closed pair of headphones..

Well look at this: http://www.industrialnoisecontrol.com/comparative-noise-examples.htm

There`s no way i listen to music at 100dB.. Those bassheads on the other hand might learn a thing or 2 from this thread though :)