Volume When Plugging Directly Into Laptops
Feb 1, 2013 at 3:46 AM Thread Starter Post #1 of 11

Basifrisk

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So I currently use a pair of Beyerdynamic DT-770 M's, that have an impedance of 80Ω. I plug them directly into my Macbook Pro (late 2008 model), and I find that instead of being too quiet, I have to stay around the 4/16 volume area on my Macbook as a maximum. (This is with the in-line volume control being in the middle)
 
Is this normal? I thought that with an impedance of 80Ωs, it should be a lot quieter.
 
 
I ask this as I am thinking of buying the DT-990s, which come in 32Ω, 250Ω, and 600Ωs. I'm trying to figure out whether the 32Ω will be too loud, or if the 250Ω will be too soft when directly plugged into my laptop.
 
The 770's have a 105db nominal SPL and the 990's have a 96db nominal SPL.
 
Thanks.
 
Feb 1, 2013 at 3:54 AM Post #2 of 11
I have heard that the 32 ohm version should not sound as good...
 
Feb 1, 2013 at 7:53 AM Post #4 of 11
Laptops often have output impedance close to 100Ω. With such high source impedance, the impedance of headphones matters much less - roughly 3dB of variation across 16-600Ω range. Furthermore, power received by the headphones is maximized when their impedance is equal to source impedance, so your DT770-80 is getting almost as much usable power as possible from this output. A lower impedance version with equal sensitivity would likely be few dB quieter.
 
Feb 1, 2013 at 8:18 AM Post #5 of 11
I find mine S600 sound MUCH more quiet on Realtek ALC1200 (integrated in ASUS P5QC) than on mine Desire HD. max volume on PC is just slightly above normal listening vol, while on my DHD I literally can't stand listening on max, it's even too much, lol.
Enable loudness equalization and see if that helps, I find it very helpful when watching movies, but don't leave it on forever, as it makes some other tracks quieter than before. Also, use VLC, it has higher volume (up to distortion).
 
Feb 1, 2013 at 11:52 AM Post #6 of 11
Quote:
Furthermore, power received by the headphones is maximized when their impedance is equal to source impedance, so your DT770-80 is getting almost as much usable power as possible from this output. A lower impedance version with equal sensitivity would likely be few dB quieter.

 
No, matching headphone and amplifier impedance is a mistake if the sound quality is important. In fact, they shouldn't match at all.
 
Impedance matching is important for maximum power transfer. But, a headphone amplifier acts as a voltage source, so impedance matching isn't ever useful. When a headphone's input impedance is less than 8 (or 10) times the amplifier's output impedance, the amp will have difficulty damping the 'phones.
 
Feb 1, 2013 at 6:30 PM Post #8 of 11
And then again, why the heck don't they just integrate those things (amps) in the higher-end cans? Can someone explain that? 
biggrin.gif

It looks like a brilliant way to compensate spikes and dips  with built-in EQ preset designed for particular HP's as well.
 
Feb 1, 2013 at 7:44 PM Post #9 of 11
Quote:
Is this normal? I thought that with an impedance of 80Ωs, it should be a lot quieter.
[...]
The 770's have a 105db nominal SPL and the 990's have a 96db nominal SPL.
 

 
The impedance of a headphone isn't the determiner for 'loudness'. It's efficiency (often quoted as a nominal SPL at a given distance for a given power output.) For loudspeakers, that's usually loudness measured with 1W input at a distance of 1m. If everything else is equal (and it never is): The greater the efficiency, the higher the SPL. The numbers you quote (105dB for the '770 vs 96dB for the '990) means the '770 will be about twice as loud as the '990. ('Twice as loud' = 10dB.)
 
It's often the case that low-impedance, full-sized headphones are inefficient and therefore require gobs of power. But they don't have to be.
 
Feb 1, 2013 at 8:35 PM Post #10 of 11
Quote:
 
The impedance of a headphone isn't the determiner for 'loudness'. It's efficiency (often quoted as a nominal SPL at a given distance for a given power output.) For loudspeakers, that's usually loudness measured with 1W input at a distance of 1m. If everything else is equal (and it never is): The greater the efficiency, the higher the SPL. The numbers you quote (105dB for the '770 vs 96dB for the '990) means the '770 will be about twice as loud as the '990. ('Twice as loud' = 10dB.)
 
It's often the case that low-impedance, full-sized headphones are inefficient and therefore require gobs of power. But they don't have to be.

 
Oh, ok.
So you're saying that there will only be a negligible difference?
 
Feb 1, 2013 at 9:14 PM Post #11 of 11
Quote:
Quote:
The impedance of a headphone isn't the determiner for 'loudness'. It's efficiency (often quoted as a nominal SPL at a given distance for a given power output.) For loudspeakers, that's usually loudness measured with 1W input at a distance of 1m. If everything else is equal (and it never is): The greater the efficiency, the higher the SPL. The numbers you quote (105dB for the '770 vs 96dB for the '990) means the '770 will be about twice as loud as the '990. ('Twice as loud' = 10dB.)
 
It's often the case that low-impedance, full-sized headphones are inefficient and therefore require gobs of power. But they don't have to be.

 
Oh, ok.
So you're saying that there will only be a negligible difference?

 
Personally, I think the difference is substantial. Even so, I can connect my (relatively inefficient) DT 990's to one of my 3 PC's or my laptop, and they can always be played much, much louder than I can stand. When I use a more-efficient 'phone, it gets too loud even earlier.
 
For a low-power device, like some DAP's, that extra 10dB sensitivity of the '770 might be the difference between a usable and an unusable headphone.
 

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