# What is headphone max output (mW)?

Discussion in 'Sound Science' started by naurispunk, Feb 5, 2011.
1. Alll headphones has this value attached to them. For example Pioneer HDJ-2000 has  3500mW.

I know that if this property is high the headphones can produce louder sound.

But what I was wondering about is - does this value represents the optimum input mW for headphones or is it the max power that these headphones can take and beyond that they will break?

In practice if I have headphones with 3500mW does that mean I have to get amp that outputs the same to get the best out of them or does it mean that I cant plug them into anything that outputs more than 3500?

That is the maximum recommended power input. Exceed that level and you risk damage to the phones and most likely you will have all ready exceeded a safe listening level for your hearing by that time. It really has more to do with the abuse tolerance then how loud they will play.

This spec tells us more -
Output sound level.......................................................................107dB/mW

From 1mW of power input, the phones produce 107dB of sound pressure. I would suggest these look like easy to drive phones and could be used from nearly any headphone jack.

3. It's the maximum power they will take. Depending on the manufactured this could be measured differently.

Option 1: Play pink noise (or any standard signal), raise the volume up until the drivers break, the value just before breaking is the one written down.
Option 2: Play pink noise (or another standard signal like A-weighted) at a certain power for a dozen hours, check that the drivers have not suffered any damage, repeat, until the drivers break or have significant damage, the next to last value is the one written down.

Between those 2 there are a multitude of possibilities, but, note that how linearly the driver behaves is not taken into account, it's about whether the driver is damaged.

4. Quote:

Many headphones don't even need more than 1 mW to produce high SPL levels.

This is supposed to be the absolute maximum power it can take before blowing up, but it's not clear under what conditions the manufacturer measured those 3.5W ... so, imo, this number has marketing value only.
And you wouldn't even want to get close to this number if the headphones were somewhere near your ears.

5. Output power simple the amount of sound energy a headphone can produce per second at a maximum. Impedance is a factor in this.

for reference

POWER = VOLTAGE X CURRENT

6. Hey guys, so I recently exposed my headphones to a loud burst of sound from my Fiio E17.  It was loud enough to cause an instant reaction to turn the thing off and pull the headphones off.  My headphones have a 1000mW output and they seem to still sound fine, although I am still paranoid.  I guess my question is how likely is it that they are damaged? I would think it should be a noticeable rattle if they were blown out especially in the bass region.  Is this a correct assumption? ( I am new to the amping world)

7.
The E17 is not capable of anything close to 1 W (1000 mW) output, so you couldn't have put that much into the headphones. The amount depends on the headphone impedance, volume setting, input level, etc., but suffice to say, it was not near the limit, whatever physically that really corresponds to for the headphones in question. But I would be a lot more worried about your ears than the headphones. Very uncomfortably loud is still not enough to damage most headphones.