[Silenced]

I want to be able to drive my headphones to about 90 dba without clipping. Under the assumption that if a headphone has enough power, most amps will be negligibly different which is the way to found out which is the minimum amplification. (for reference these are vintage headphones with a very low sensitivity and ohm rating)

 

[Justice Strike]

yes

 

[Silenced]

Quote:

Originally Posted by Justice Strike /img/forum/go_quote.gif yes

Enlighten me =)

 

[Justice Strike]

x

 

[Silenced]

Quote:

Originally Posted by Justice Strike /img/forum/go_quote.gif x

?

 

[Sovkiller]

Here is a table made by Rane that can give you an idea...

 

[iriverdude]

Not really it's the same for speakers, a cheap amp can drive speakers to loud levels, but at those levels the amp may have distortion. Basically need formula with driver sensivity, impedance, impedance along the frequency response, amplifier power output, and THD levels at specific power output levels, plus amps ability to drive low loads, and how the amps THD is effected for these harder to drive speakers.

 

[jcx]

also need an appreciation of dynamic headroom requirement, try looking at live music levels in:

HeadWize - Article: Preventing Hearing Damage When Listening With Headphones (A HeadWize Headphone Guide)

90 dB could be a OK average level for a few hrs - not as all day background music

but if you listen to music with real life dynamics you can need 20 dB more headroom to avoid clipping - I look for the ability to drive the headphone to 120 dB in a "audiophile" amp

 

[iriverdude]

oh also forgot distance to listener not a problem with headphones although same principle I guess, if I remember correctly for every meter dB level goes down 3dB, and for every 6dB (2m) you need double the power.

 

[Silenced]

hmmm, harder than I thought... so I guess the only way of knowing is by seeing what amps others have used and had good experience with for the headphone? That always sucks because I have a hard time trusting everybody's opinion.

 

[DanD]

You need to find the max voltage the amp put out and the impedance and the sensitivity of your headphones and the max power it can take..

It's similar to how you calculate for amp requirement for loudspeaker but you don't need to add an extra 3 dB because headphone are sealed to each ear, where stereo there are two speakers and you don't need to worry about distance. (unless you're dealing with something like K1000)

Say Your headphones has sensitivity of 80 dB/1mW. To gain the next 3dB you need to double your power.

That is if you feed it 1mW you get 80 dB.
2mW you get 83 dB
4mW you get 86 dB
8mW you get 89 dB
16mW you get 92 dB.... etc

Headphones with Headphones Amps can all typically reach above 100 + dB, some above 120 dB even. So to get 90 dB shouldn't be a problem as long as your headphone can take the power.

To work out how many Watts your headphone is getting from the amp, you need to get the impedance and the voltage out specs of your amp.

You can use this site like this one below to convert from amplitude to power:

Conversion between dBm - dBW - W and dBuV - dBV - V