SPL question

[btcomm]

What would be the difference between SPL at 108 dB vs 112 dB? Will you feel more pressure from the 112 dB headphones vs the 108 dB for more base you can feel?  Does it mean you will feel full pressure when it reaches the specified dB? Does it mean the the 112dB headphone can get louder than the 108dB one or does it mean something different all together?
 
 

 

[stv014]

Quote:

What would be the difference between SPL at 108 dB vs 112 dB? Will you feel more pressure from the 112 dB headphones vs the 108 dB for more base you can feel?  Does it mean you will feel full pressure when it reaches the specified dB? Does it mean the the 112dB headphone can get louder than the 108dB one or does it mean something different all together?

112 dB SPL is somewhat (by a clearly audible, but not very large margin) louder than 108 dB. The difference is equivalent to about 2.5 times more power, or about 1.6 times higher voltage. If these are quoted from the manufacturer specs of headphones (the numbers look familiar from Sennheiser specs), then they simply mean how loud the headphone will be from a given fixed input level, which is usually either 1 mW, or 1 Vrms - for Sennheiser, the latter is typical. Therefore, a higher number, at the same reference level (1 mW or 1 Vrms), generally means that the headphone is easier to drive. But to know exactly how loud a headphone can be from a particular source, you also need to know its impedance, and some basic electrical characteristics of the output of the source; manufacturers are also often optimistic with their sensitivity specifications.

 

[btcomm]

 
Quote:

112 dB SPL is somewhat (by a clearly audible, but not very large margin) louder than 108 dB. The difference is equivalent to about 2.5 times more power, or about 1.6 times higher voltage. If these are quoted from the manufacturer specs of headphones (the numbers look familiar from Sennheiser specs), then they simply mean how loud the headphone will be from a given fixed input level, which is usually either 1 mW, or 1 Vrms - for Sennheiser, the latter is typical. Therefore, a higher number, at the same reference level (1 mW or 1 Vrms), generally means that the headphone is easier to drive. But to know exactly how loud a headphone can be from a particular source, you also need to know its impedance, and some basic electrical characteristics of the output of the source; manufacturers are also often optimistic with their sensitivity specifications.

Thanks for replying.
 
I am looking at Sennheiser's right now.
 
So from what I understand, the spl dB is how loud they will be at a certain power level, so the 112 DB is easier to drive because it's louder at a the same power level.  The specific headphones I'm looking at are hd 555 which is what I have now and the hd 518's that I have ordered to replace them.  I think both versions are 50 ohms and I noticed the 518's are 108 dB spl and the 555's are 112 dBspl.  Since they are both 50 ohms does that mean the 555's can get louder?  Can one or the other get louder than the other with no distortion based on that rating?  Or could they maybe get to the same volume with no distortion it just takes more power?
 
I'm replacing the 555's because they cracked :\.

 

[Peshmerga]

 
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So from what I understand, the spl dB is how loud they will be at a certain power level, so the 112 DB is easier to drive because it's louder at a the same power level.  The specific headphones I'm looking at are hd 555 which is what I have now and the hd 518's that I have ordered to replace them.  I think both versions are 50 ohms and I noticed the 518's are 108 dB spl and the 555's are 112 dBspl.  Since they are both 50 ohms does that mean the 555's can get louder?  Can one or the other get louder than the other with no distortion based on that rating?  Or could they maybe get to the same volume with no distortion it just takes more power?
 
 

 
Simply put:  The sensitivity ratings of both headphones just means that with the HD518, you will have turn up the volume more to listen at the same loudness as you once had with the HD555. Slightly more.

I hope you're not listening to music at these sound pressure levels.  Cause you will have permanent hearing loss in only a few minutes with a headphone screaming at 108 dB.  112 dB does that in less than half the same time as 108 dB.
 
 
 

 

[tinyman392]

There is a difference between dB SPL and just dB. dB SPL is measured in Pascals (Pa) while dB is measured in decibels (dB). So there is a conversion required to get it to what we are used to seeing on the FR graphs.

That said, sensitivity deals mainly with loudness of a pair of headphones. For every W or mW of power you feed a pair of headphones, it'll output x dB SPL. That is what the rating means. So if the rating is 100 (easy number to calculate), and you gave it .5 mW of power and it was rated at 100 dB SPL,/ mW, you would get a loudness of 50 dB SPL.

50 dB SPL is very loud BTW. That is why resistance is also important to keep these levels lower. Something that has 16 ohms of impedance will cut the output by a factor of 8 while something with 32 will do by a factor of 16. That way you won't blow out your ears as easily (or your drivers).

Hope this is helpful.

 

[Peshmerga]

 
Quote:

For every W or mW of power you feed a pair of headphones, it'll output x dB SPL. That is what the rating means. So if the rating is 100 (easy number to calculate), and you gave it .5 mW of power and it was rated at 100 dB SPL,/ mW, you would get a loudness of 50 dB SPL.

Sound pressure level is measured on a logarithmic decibel scale.  Your example is miscalculated.  The correct formula to find a certain dB SPL, given that you know the sensitivity rating, and you measured how much power is going into the headphone is:
 
dB SPL = Sensitivity in dB/mW + 10 * LOG(mW)
 
So going by your example of 1mW/100 dB SPL and 0.5mW given, you get:

 ​

~97 dB SPL = 100 + 10*LOG(0.5)​

 ​

97 dB SPL rounded up.​

 

[Headzone]

 
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Can one or the other get louder than the other with no distortion based on that rating?  Or could they maybe get to the same volume with no distortion it just takes more power?

You can't make any conclusions about the headphones loudness based on that rating.. And you shouldn't care about it, cause it doesn't matter. Both of them are more than loud enough.

 

[skamp]

It matters. Lord Voldemort suggests shooting for a SPL of 110 dB if you're listening to more or less audiophile (quiet) albums. The Sennheiser HD 518 would require 31.6 mW to reach that level, which a portable player, for instance, or a laptop, might not be able to output. It's quite easy to max out an iPod or a laptop, especially when they're subject to EU limitations on volume.

 

[Headzone]

Yeah I was thinking about the max spl considering you already had an amp lol. I agree my statement is wrong because I more like said it doesn't matter in any case..
 
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Or could they maybe get to the same volume with no distortion it just takes more power?

Possibly but the problem is we don't know how much power they can handle.
 
Btw Aren't the 518's a downgrade from 555's? I thought the 555 new equivalent was 558.
 
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The Sennheiser HD 518 would require 31.6 mW to reach that level

HD518's sensitivity is 108dB @1vrms. If 1vrms is ~5mW, they would require ~8mW to output 110dB?

 

[btcomm]

Depends the 518's have a lower frequency reponse than the 555's and from what I have read have more bass which I enjoy. Also my 555's cracked I'm not just replacing them for something better.
 
Quote:

Yeah I was thinking about the max spl considering you already had an amp lol. I agree my statement is wrong because I more like said it doesn't matter in any case..
 
Quote:

 
Or could they maybe get to the same volume with no distortion it just takes more power?

Possibly but the problem is we don't know how much power they can handle.
 
Btw Aren't the 518's a downgrade from 555's? I thought the 555 new equivalent was 558.
 
Quote:

The Sennheiser HD 518 would require 31.6 mW to reach that level

HD518's sensitivity is 108dB @1vrms. If 1vrms is ~5mW, they would require ~8mW to output 110dB?