which value of impedance makes me know that the phone has high or low impedance?
Mar 29, 2008 at 3:38 AM Thread Starter

#### lucky_star

##### Banned
just as my title
can anyone tell me the appropriate value of impedance to make me know that it is low impedance or high impedance phone?
is low impedance equal to high sensitive phone?
and high impedance equal to low sensitive phone?
thanks

Mar 29, 2008 at 3:42 AM
low = 16 ohms
high = 600 to 2000 ohms

Edit: And no, there is no guaranteed correlation between impedance and sensitivity.

Mar 29, 2008 at 3:52 AM
so 30ohm- 150ohm is also low impedance right?
how can i know which phone is high sensitive or low sensitive?

Mar 29, 2008 at 4:15 AM
Quote:

 Originally Posted by ericj /img/forum/go_quote.gif low = 16 ohms high = 600 to 2000 ohms Edit: And no, there is no guaranteed correlation between impedance and sensitivity.

For consumer headphones there is a rough correlation I'd say, but once into the h-fi territory there is enough discrepancy (especially from those AKGs from what I've read) between impedance and sensitivity due to differences in designs that the only sure way to know for sure is to ask around.

Mar 29, 2008 at 4:16 AM
Although ericj is definitely more knowledgeable on question regarding impedance and sensitivity, my own experience tell me (which can be wrong):
Assuming sensitivity around 100dB SPL/mW, headphone with < 50 ohms often are easy to drive from a portable source; headphone with 50 ~ 120 ohms generally benefit from amping; headphone > 120 ohms are difficult to drive with out amping. Also, the higher the sensitivity the easier to drive, and headphone with 96db SPL/mW or below often sound tiny with out amping. Remember, this is just my observation on 'phones that I have experience with, might not represent the whole case.

Mar 29, 2008 at 6:34 AM
thank a lot now i understand.
one more newbie question: when i read reviews of headphone, people usually say GS1000 or Denon D5000 isn't very good at midrange. what is the midrange? is it the voice of singers or the sound of instrument?
thanks again

Mar 29, 2008 at 6:40 AM
i actually think it depends...

id say:
iems, earphones
below 32 ohm - low
above 32 ohm - high

under 150 ohm - low
above 150 ohm - high

Mar 29, 2008 at 6:53 AM
Mid range is about 200Hz ~ 5kHz. Check out the sticky on the forum for glossary for describing sound.

Mar 29, 2008 at 6:55 AM
Quote:

 Originally Posted by lucky_star /img/forum/go_quote.gif thank a lot now i understand. one more newbie question: when i read reviews of headphone, people usually say GS1000 or Denon D5000 isn't very good at midrange. what is the midrange? is it the voice of singers or the sound of instrument? thanks again

Kind of. Most sounds will emit into multiple ranges, and there is some overlap between those ranges as well -- so what may be considered the upper spectrum of mid-range may also be part of the lower highs. Essentially, mids are probably the single most important range, as the majority of audio will be there (voice, main instrument sounds).

The reason why people can notice even subtle differences in mid-range performance is because we are far more used to this range in our day-to-day lives, unless of course you are a chipmunk.

If a set of headphones has poor mid-range reproduction, you will know it. This varies from person to person, as this is a very, very subjective matter. Even identical twins "hear" differently. That's why you'll see many people with differing opinions on headphones, one person will say the mids rock, another will call them the worst headphones ever made.