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Sennheiser IEM Power Handling

mike7877

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I have some ie200 IEMs from Sennheiser and haven't been able to determine their RMS and peak power rating.

There are two specs given which at least might be relevant information:
First, there's their efficiency, which is either 101 or 104dB/mW, and
second, there's a maximum level of 119dB.

+15dB would be ~32x more power, +18dB would be ~64x more power. Since 101 (or 104) are at 1mW, 32 x 1mW implies 32mW, and 64x : 64mW.

~50mW seems... low, though. 30 seems, definitely too low (and 104 is the more likely correct efficiency, so...
Should I just go with this assumption?
Does anyone know this top secret, heavily redacted information? xD
 
The only mention of 119dB that I could find was in relation to their sensitivity, which the website claims is 119dB/V and the quick guide claims is 124dB/V (both at 1kHz, lol).

Where does it say that 119dB is the maximum level?
 
The only mention of 119dB that I could find was in relation to their sensitivity, which the website claims is 119dB/V and the quick guide claims is 124dB/V (both at 1kHz, lol).

Where does it say that 119dB is the maximum level?

Hmm. I was looking everywhere, and it was the only value I found anywhere. I didn't bookmark it and was on like 50 sites, so unforunately...

It does seem likely that I or they misattributed the 119dB

The IE 200s are apparently 18 ohms, so 1V into 18 ohms is 56mW. With 56mW it makes 119dB, and 1mW: 101dB. 18dB is about 64x power, and since 56 is pretty close to 64, it looks like 101dB/mW is the correct efficiency rating.

Yeah, the dB/V is just one of the two standard units of measure for headphone efficiency - it has no bearing on maximum level. It could probably be given for a headphone that's not actually able to generate that SPL - extrapolated from a lesser voltage.

I don't want to cook the tiny 7mm things... They do seem extremely capable though, especially coming from my last IEMs (Salnotes Zero). The IE 200s bass has less distortion even though its driver membrane has less than half the surface area of the Zero's - and the midrange just seems... more realistic. The IE 200 can be a lot smaller (and it is - literally ~half the size) of the Zero with the same frequency extensions etc. (approximately...), and since the driver apparently can move at least more than double the distance of the 10mm in the Salnotes Zero before distorting, it takes advantage of having the smaller, lighter, more rigid, less resonant case. Anyway...

I really really like knowing the power ratings of things... I'm very happy to know that my HD 650s are capable of 500mW average power and put out ~100dB per mW over most of the audible spectrum. I like knowing that my ears will be very uncomfortable before any damage is done to the drivers, unless the damage is from a freak accident - something like a tonne of LF energy immediately. Since I generally try to take care of my hearing, I know that there's nothing extra I have to do to ensure my headphones are looked after as well. Random fact: HD 650 xmax is about 2.5mm peak to peak, pretty impressive IMO {{I had the ear pad and flat foam piece off, and you can see the center half of the driver right there, so I though: why not?}}

I've even tried looking for the power rating of their other IEMs with no luck! Maybe Sennheiser believes that people don't need the power ratings because the IEMs can go to uncomfortable levels before being damaged themselves...

I did a bass test of the IE 200s, the same thing I did with my Salnotes Zeros: Put various low frequencies to them and increased the level by 0.1dB until xmech is reached (audibly when the voice coil former part of the membrane reaches the magnet, it's a very faint clicking). When doing the Salnotes Zero, I actually began smelling the drivers in the 50Hz range. Granted, I'd already been testing 20, 30, 42, 47Hz, each for maybe 20-30 seconds up to xmech, but still, it's pretty extreme to be literally smelling up the place (Zeros don't smell during normal use. They sound decent if you equalize - they're good value for $20)

Maybe you see now why I'm slightly anxious to know the power rating
 
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tl;dr under -----

I put 20Hz into them at 0.776V for 1.5 hours with no adverse reaction (no smell lol). That was about 10dB below xmech (the driver's mechanical limit). I don't know what their impedance is at that frequency, but if it's 18 ohms like the rating, the IE 200s are good with 33mW continuous, which is quite loud.

I'm thinking of doing a bit of an experiment.
Use 250Hz instead of extremely low frequencies to better approximate average driver movement during music at power levels tested.
Place IE 200 onto carpet or similar material for small amount of heat retention (like wearing)
Starting at 40mW and increasing by 10mW every 5 minutes, send 250Hz until driver impedance increases by x %.
(it's not like there's a passive crossover interacting with the driver's changed impedance causing ugly operation, but I still think this is fair.
Second aspect (maybe): I have an IR thermometer - if the external temperature rises by more than 10 degrees C before a (3 or 5%?) increase in impedance, that will be the max power handling. If the impedance rise is first (I think it will be) then that will be the as

I'm thinking it's fair to say that once a driver's impedance rises to between 3-5%, it's no longer operating as intended. If it's a speaker using 1% parts (and those parts are the correct size for the driver{which they should be if they're 1% parts...}) once the driver's impedance changes more than 1%, it's out of spec. I'm not saying that it'd sound bad (a speaker of quality drivers and box, and crossover of 1% parts is still a very good speaker with one part suddenly out 4%. And a speaker of 10% parts might sound better when the woofer's impedance rises 7% lol).

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Does anyone know, roughly, how much impedance usually rises when you give a [properly specified] speaker its RMS rating? Obviously it varies a bit, but this should be a good way to find the IE 200's power rating
 
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