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Technical factor to consider and compare in choosing IEM ? - Page 2

post #16 of 23
Quote:
Originally Posted by JohnSantana View Post

Ah yes, so the factor to consider are as follows:

 

1. Number of Drivers

2. Crossover (more crossover means better sound quality)

3. Bores (Yes means better sounding)

4. Comfort

5. Isolation

6. Frequency response (at least within 20-20k Hz range)

7. Impedance (lower impedance means not needing amplification to produce sound clarity).

 

Please let e know if I need correction in those factors above.


Here's my take on those 7 points:

 

1. As has been said before, high number of drivers does not mean better sound. Some single-driver dynamic IEMs sound better than 3-way BA. More BA drivers have the potential of sounding better (wider frequency response, less distortion, higher output level), because two BAs cannot cover 20 Hz - 20 kHz.

 

2. No crossover is the best crossover. :)

 

3. Bores as in vents? More vents don't guarantee better sound but maybe a more balanced/weaker bass response.

 

4. Comfort is important.

 

5. Isolation too, if you need it, but isolation will suffer with vents and also if the IEMs don't fit right (comfort?).

 

6. FR is very important. Doesn't have to be completely flat but there shouldn't be big peaks and dips. Also, bass might be boosted and treble rolled-off by a few dB (depends on your preference).

 

7. Impedance and sensitivity is a bit more complicated. Generally you do want a device/amp with a very low noise level if you have very sensitive IEMs, else you'll probably hear a constant hissing noise.

Best would be an IEM with very high impedance and also very high sensitivity, so that the amp doesn't have to provide much current (-> lower distortion, channel crosstalk, battery life ...).


Edited by xnor - 10/12/12 at 7:36am
post #17 of 23
Quote:
Originally Posted by xnor View Post

Best would be an IEM with very high impedance and also very high sensitivity, so that the amp doesn't have to provide much current (-> lower distortion, channel crosstalk, battery life ...).

 

Well, not *very high* because battery powered devices typically have a harder time generating high voltage, than they do current. 

post #18 of 23
Quote:
Originally Posted by liamstrain View Post

 

Well, not *very high* because battery powered devices typically have a harder time generating high voltage, than they do current. 

 

 

Well, as an example, check out HiFiMan RE-262 (I haven't heard it, but it's a dynamic driver IEM, pretty flat impedance):

http://www.innerfidelity.com/images/HiFiMANRE262.pdf

 

149 ohms, 0.043 Vrms to reach 90 dB SPL.

 

And we have people saying that it benefits a lot from "amplification" and so on.

post #19 of 23

You don't need much voltage if the headphones also have very high sensitivity. ;) Of course, in reality there are limits and you cannot have both.

 

But indeed, the latest, properly implemented portable devices do not struggle driving 16 ohm loads. Distortion and crosstalk still increase a bit though.

 

Regarding the 150 ohm IEM needing amplification: the reviews I've seen contained guesses and hunches such as "since they are 150 ohms I expected them to demand an amp", or "150 ohms and a sensitivity of 95 dB, so an amp is recommended" or the typical everything improves with amp X, if you don't have that amp you shouldn't buy that IEM ...

 

Some of the amps used actually perform worse than an iPhone yet everything improves if you just get that amp.. if you don't you really miss out on the improvements on everything.


Edited by xnor - 10/12/12 at 10:11am
post #20 of 23
Thread Starter 
Quote:
Originally Posted by liamstrain View Post

 

The frequency response. The top left graph - should try to trend as flat as possible. There are some caveats to that, but as a general rule, for accurate response, that's a good one. 

thanks Liam,

 

when comparing between the AUD $ 95 UE700 http://www.innerfidelity.com/images/UltimateEarUE700.pdf it is rather flat but with the USD $ 5000 Stax SR-009 http://www.innerfidelity.com/images/StaxSR009.pdf it is not that flat but rather fluctuated ?

post #21 of 23

the UE700's deviations from flat are deeper, despite the 009 having more of them. Overall the 009 trends flatter (think of it as an average, combined with a total deviation from 0). 

 

Personally, I also don't consider the 009 a good reference monitor but it is a fantastic headphone (likewise the LCD 2). 

post #22 of 23
Thread Starter 
Quote:
Originally Posted by liamstrain View Post

the UE700's deviations from flat are deeper, despite the 009 having more of them. Overall the 009 trends flatter (think of it as an average, combined with a total deviation from 0). 

 

Personally, I also don't consider the 009 a good reference monitor but it is a fantastic headphone (likewise the LCD 2). 

 

Many thanks for the response Liam, so in this case the closer lines drawn to the 0 dB the better the performance is ?

post #23 of 23
Quote:
Originally Posted by JohnSantana View Post

 

Many thanks for the response Liam, so in this case the closer lines drawn to the 0 dB the better the performance is ?

 

Generally speaking, the more accurate the performance is (this is not a hard and fast rule, but it's a good guideline). Better is subjective. 

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