Headphone impedance
Jul 28, 2011 at 10:02 AM Thread Starter Post #1 of 12

shrimants

1000+ Head-Fier
Joined
Nov 8, 2006
Posts
1,175
Likes
79
I'm looking through various portable source components and tryign to decide which I should get and weighing the pros/cons of each. As ive been doing this I've found that with no load certain players have an extremely flat frequency response but with a low load (16-32 ohm) they have severe bass roll off.

Does this mean that bass roll off can be reduced with high impedance headphones? How does one go about getting the full audio spectrum from 6hz (at least) all the way up to 20khz? Is the only way to do this via EQ and/or portable amps (as far as portable source gear goes)?
 
Jul 30, 2011 at 4:26 AM Post #2 of 12

JGOelfke

100+ Head-Fier
Joined
Jan 9, 2011
Posts
156
Likes
12
I don't know how much this will help you, but I have a pair of the 32 ohm DT770s. I noticed a huge difference in the bass timbre when they are amped vs. running straight out of my iPod. 
 
Jul 30, 2011 at 3:34 PM Post #3 of 12

jack black

New Head-Fier
Joined
Jul 26, 2011
Posts
30
Likes
11
I'm not sure impedience is the only story. There is a nice comparison between MDR-V6 and HD280pro, and while HD280pro is a better headphone, V6 sounded much better on iPod due to it's high sensitivity, low power requirement, and intrinsingly strong bass:
http://byrneweb.com/sunburn/audio/hd280vsv6.html
 
BTW, V6 is 63 ohms, and HD is 64 ohms.
 
This review steered me toward V6 and I don't regret that.
 
Jul 30, 2011 at 8:06 PM Post #4 of 12

Uncle Erik

Uncle Exotic
Joined
Mar 18, 2006
Posts
22,596
Likes
505
Remember that you have to consider the amp's output impedance and output power as well as the headphone's sensitivity and impedance.

Headphone impedance is only 25% of what's going on. You can't make a determination without knowing the rest.

That's like saying that x + y/z = n. You know y is 32. But you cannot work the equation knowing only one variable.
 
Jul 30, 2011 at 11:21 PM Post #5 of 12

shrimants

1000+ Head-Fier
Joined
Nov 8, 2006
Posts
1,175
Likes
79
While your answers were helpful, they just made me further confused as to what headphone i should pick....dag nabbit.
 
Aug 1, 2011 at 11:36 AM Post #8 of 12

imackler

Headphoneus Supremus
Joined
Nov 17, 2008
Posts
5,834
Likes
411
Uncle Erik,
What could I read to get a better sense of these four factors? Any article or explanation on line, etc.?
Thanks!
Quote:
Remember that you have to consider the amp's output impedance and output power as well as the headphone's sensitivity and impedance.

Headphone impedance is only 25% of what's going on. You can't make a determination without knowing the rest.

That's like saying that x + y/z = n. You know y is 32. But you cannot work the equation knowing only one variable.



 
 
Aug 2, 2011 at 4:37 AM Post #9 of 12

Uncle Erik

Uncle Exotic
Joined
Mar 18, 2006
Posts
22,596
Likes
505
My favorite book on basic electricity is "There Are No Electrons: Electronics For Earthlings," by Kenn Amdahl.

Possibly the most entertaining book on a dry subject. It explains all the basics and you'll have fun reading it. After that, poke around Pete Millett's website for loads of free texts.

Also, I'd strongly recommend building something like a CMoy. Only $20 and spend some time learning what's going on as you build. Nothing is better than hands-on experience to get your head around something. Even better, you can move onto bigger projects. Like building an amp that would cost $2,000 commercially for $400-$500.
 
Aug 3, 2011 at 10:53 AM Post #10 of 12

The Monkey

Monkey See, Monkey DAC
A really sick dud
Joined
Oct 28, 2004
Posts
8,010
Likes
135


Quote:
My favorite book on basic electricity is "There Are No Electrons: Electronics For Earthlings," by Kenn Amdahl.

Possibly the most entertaining book on a dry subject. It explains all the basics and you'll have fun reading it. After that, poke around Pete Millett's website for loads of free texts.

Also, I'd strongly recommend building something like a CMoy. Only $20 and spend some time learning what's going on as you build. Nothing is better than hands-on experience to get your head around something. Even better, you can move onto bigger projects. Like building an amp that would cost $2,000 commercially for $400-$500.


I've been looking for a book like that.  Thanks for the recommendation, Erik.
 
 
Feb 19, 2013 at 1:53 PM Post #12 of 12

RexPrice

Member of the Trade: Skullcandy
Joined
Feb 11, 2013
Posts
3
Likes
12
Some amplifiers use a coupling capacitor at the output to block DC bias voltage in an amplifier from being passed on to the headphone or speaker.  This DC bias could displace the diaphragm from a centered position (and may cause the voice coil to heat excessively).  Attaching a headphone to the amplifier output now creates a high-pass filter (good image on the Wiki page, see Figure 1).  The cut-off or corner frequency varies with 1/R (where R is the DC resistance of the headphone), so increasing R (high impedance headphone) will cause the corner frequency to go down.
 
Some amplifiers do not use a blocking capacitor at the output (because they are built to minimize the DC bias voltage at the output) and these amplifiers are capable of a flat response down to around 6 Hz (I measured a Presonus headphone amplifier that had flat response when loaded with a low impedance headphone.
 

Users who are viewing this thread

Top