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Problem with driving 250 ohms version of Beyerdynamic DT990

post #1 of 5
Thread Starter 

Hey I've been playing with those headphones for a couple of days and noticed a weird phenomenon:

When I plug them directly into my HP 4411s (a business notebook). It sounds OK and the volume's set at about 70-75%.

But when I use E17, I use 12 gain and the volume is about 30 (out of 60).

 

Did my notebooks gain some super power secretly or Fiio sucks?

post #2 of 5
Quote:
Originally Posted by syryanyang View Post

When I plug them directly into my HP 4411s (a business notebook). It sounds OK and the volume's set at about 70-75%.

But when I use E17, I use 12 gain and the volume is about 30 (out of 60).

 

So, what is the problem exactly ? You cannot simply compare the position of volume controls, because they can have different taper functions. The output level can be a linear, quadratic, exponential, or other function of the volume setting, so "50%" or "12 o'clock" volume can be anything. The FiiO could increase much more in volume from 30 to 60 than the laptop does from 50 to 100. It is also possible that the input voltage you feed to the E17 is low (this is only relevant if you use it as an amplifier only).

However, it is entirely possible that the laptop alone has enough power to drive the headphones at your preferred listening volume. There is a wide variation in what loudness people listen to music at, and music with low dynamic range (which includes most popular styles) also needs less power, because it does not have peaks much higher than the average level. The FiiO might have about 10 dB higher maximum output voltage (i.e. slightly more than 3 times as high, something line 2.5 Vrms instead of 0.8 Vrms, these are realistic estimates), and that translates to about twice the perceived loudness.


Edited by stv014 - 11/20/12 at 1:11am
post #3 of 5
Thread Starter 
Quote:
Originally Posted by stv014 View Post

 

So, what is the problem exactly ? You cannot simply compare the position of volume controls, because they can have different taper functions. The output level can be a linear, quadratic, exponential, or other function of the volume setting, so "50%" or "12 o'clock" volume can be anything. The FiiO could increase much more in volume from 30 to 60 than the laptop does from 50 to 100. It is also possible that the input voltage you feed to the E17 is low (this is only relevant if you use it as an amplifier only).

However, it is entirely possible that the laptop alone has enough power to drive the headphones at your preferred listening volume. There is a wide variation in what loudness people listen to music at, and music with low dynamic range (which includes most popular styles) also needs less power, because it does not have peaks much higher than the average level. The FiiO might have about 10 dB higher maximum output voltage (i.e. slightly more than 3 times as high, something line 2.5 Vrms instead of 0.8 Vrms, these are realistic estimates), and that translates to about twice the perceived loudness.

Ok my question is, if the laptop alone is enough to drive my headphones,(in terms of loudness?), then an additional amp is unnecessary? 

Also how is it possible that my business laptop being able to drive high impedance headphones (DT990) fine, but back when I had Denon AHD5000, I had to crank the volume to MAX?


Edited by syryanyang - 11/20/12 at 1:25am
post #4 of 5
Quote:
Originally Posted by syryanyang View Post

Ok my question is, if the laptop alone is enough to drive my headphones,(in terms of loudness?), then an additional amp is unnecessary? 

 

If you think the laptop sounds great (while onboard audio is often poor, it can be decent on some computers if it is well implemented), and cannot hear any improvement with the FiiO, then you might just as well use the laptop.

 

Quote:
Originally Posted by syryanyang View Post

Also how is it possible that my business laptop being able to drive high impedance headphones (DT990) fine, but back when I had Denon AHD5000, I had to crank the volume to MAX?

 

Is this comparison made with the same laptop, and under the same conditions (same audio settings, same music, etc.) ? If yes, then the headphone jack on your laptop could have very high output impedance, and that reduces the voltage on the low impedance Denons significantly, but not as much on the DT990. You may also have used the Denon from a line output, while the DT990 from an amplified headphone output (there might be a Windows driver setting to select which mode the audio output jack should operate in, for example).

post #5 of 5

Heya,

 

Quote:
Originally Posted by syryanyang View Post

Hey I've been playing with those headphones for a couple of days and noticed a weird phenomenon:

When I plug them directly into my HP 4411s (a business notebook). It sounds OK and the volume's set at about 70-75%.

But when I use E17, I use 12 gain and the volume is about 30 (out of 60).

 

Did my notebooks gain some super power secretly or Fiio sucks?

 

Quote:
Originally Posted by syryanyang View Post

Ok my question is, if the laptop alone is enough to drive my headphones,(in terms of loudness?), then an additional amp is unnecessary? 

Also how is it possible that my business laptop being able to drive high impedance headphones (DT990) fine, but back when I had Denon AHD5000, I had to crank the volume to MAX?

 

Amplification occurs in two steps, voltage and then current. Each device you're using has different builds, so they are designed differently. You laptop can't raise voltage fast enough, so you have to turn the volume up high. Your E17 hits voltage faster, so it doesn't have to be turned up as high (or you've set a base gain increase, which is the same as just increasing the volume by that much automatically).

 

Your laptop can drive them enough to listen to them, but that doesn't mean they're fully dyanmic. I would play back some low bass tones, usually underpowered headphones reveal right there, play back a 30hz or 40hz tone and listen. If it's muddy, loose, and clipping, then you need power. If it's tight, controlled, and a very solid hum with no breaks, then you're power is sufficient probably.

 

The Denons were low impedance, but they still really benefit from current. It just shows that your laptop has high impedance output, so it basically drives some voltage, but has next to no current output in the second step, so a low impedance headphone like the Denon needs everything it's got to make volume. The higher impedance headphone that just needs voltage, but little amounts of current, will operate better on your laptop's output, because your laptop is clearly ok for voltage gain, but terrible at current gain.

 

It's not that your laptop is good or bad, it's simply using a different kind of amplification method.

 

The E17 is superior in every way and handle both headphone types without being maxed out the way your laptop is.

 

Very best,

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