How do you know if an IEM needs amped?

Quote:

Originally Posted by 7Virtues 

Are there any that even require to be amped?

I'm new here, so forgive my possibly too simple explanation, as the "Output Impendance" gets higher (measured in Ohm), an IEM becomes harder to drive, thus the requirement of an amp...

To answer your question, I don't think any IEM "require" an amp, but when you pair a low impendance player like a Sansa Clip+ with a high impendance IEM, you only get a tiny sound, and while getting an "amp" isn't a "must", you got no other choice...

Quote:

Originally Posted by Xinn3r 

I'm new here, so forgive my possibly too simple explanation, as the "Output Impendance" gets higher (measured in Ohm), an IEM becomes harder to drive, thus the requirement of an amp...

 

To answer your question, I don't think any IEM "require" an amp, but when you pair a low impendance player like a Sansa Clip+ with a high impendance IEM, you only get a tiny sound, and while getting an "amp" isn't a "must", you got no other choice...

Correct, some IEMs have impedances of like 8 ohms, these phones are impossible to make use of without an amp to be honest.

Balanced armature based earphones do have low impedances, but you should also remember that their sensitivity is relative high. So even if the impedance is low doesn't mean your need an amplifier.

Output impedance of smartphones, mp3 players vary alot. You should check if the output impedance is relatively the range of the earphones. If so you might need to get an amp if there isn't sufficient current from your source

Good answer. The answer is probably deeper than anyone here can readily answer. We are not a forum of scientists. We are a forum of audiophiles. So, we'll believe what whatever we want. (And, I'm not very good at explaining things, even if I am very familiar with them. I'm sure someone will turn my explanation into something intelligible if what I wrote is unintelligible.)

If your source has very high Ω output impedance, it will have a hard time driving low Ω earphones especially as bass resolution and some highs rely on low Ω. Generally, low notes drop output impedance half, sometimes more. An IEM with 18Ω can hit 6Ω on bass notes, and if your player has a 32Ω output, you won't get any of that resolution in the lower notes. When the signal load returns to 32Ω or higher, the player will have no problem playing the resolved material.

That said, modern SOC players can generally output very low Ω loads. My iPod touch 4G has NO problem with any earphone I've tried, even earphones that jump down to 6Ω on low notes. My Sony players, however, are dead after about 16Ω. The T51 is as good as the iPod touch, but has more headroom if you want to break your ears. (See below.)

That is only technically the most important audio-important issue. Another issue, and the one people most quote when talking about hard-to-drive earphones, is just volume. If you don't get enough volume, you may want an amp, but I'd be careful. A lot of people who think they need an amp, merely listen to music way too loudly. Even noise isolating earphones that can hit over 90dB with no problem from any source, are considered by some to be too quiet.

If you think you need an amp, check whether your listening volume is too loud. If you can't do it at home, you can take your source and earphones to an audiologist and measure there. Be careful with your hearing.

The final issue is somewhat delicate. If you are pushing your earphones too loud and your player goes into sizzle territory where it doesn't have the power to sustain loud volumes (especially with low Ω/high sensitivity earphones), high volumes (above 90% of the volume pot or volume slider of your player) can become 'thin' for lack of a better term. 

If that is your problem, you had BETTER check with an audiologist as again, most players are more than capable of burning your ears without an amp and don't need it for comfortable and safe listening levels.
 

Quote:

Originally Posted by KarmaIncluded 

Balanced armature based earphones do have low impedances, but you should also remember that their sensitivity is relative high. So even if the impedance is low doesn't mean your need an amplifier.

Output impedance of smartphones, mp3 players vary alot. You should check if the output impedance is relatively the range of the earphones. If so you might need to get an amp if there isn't sufficient current from your source

Yes, "need" may not me the best wording.  None really "need" an amp but an amp can make many IEM's sound a little bit better.  The two areas are;

1)  The line-out on a player is typically a little cleaner sounding that the headphone out so grabbing the signal through the line-out may provide just a touch more clarity.

2) As was mentioned above, the volume.  If you tend to listen on the loud side and you are getting distortion or hear that the continuity of the music is struggling to keep up at the higher volumes, then, yes, an amp will generally help out there as well.  Whether the volume level is safe and for what duration period is a whole nother topic.