[Parall3l]

Hey guys, just wondering why some people claim FR graphs doesn't measure the sound signature correctly ? Apart from having different humidity, position and shape of ear canal, I can't think of any other factors affecting the perceived sound. However this still doesn't explain people claiming that a headphone which measures perfectly neutral from all sources of FR graphs as having tons of bass impact. How is this possible ? Is it because the headphones also produces air movement below 10hz, which can be felt, but not shown in the FR graphs ? 
 
Thanks in advance 

 

[Head Injury]

Resonance at different frequencies isn't captured by frequency response graphs, but can alter the perceived sound. See purrin's work with waterfall graphs up in the Headphones forum. THD in the bass can also affect bass impact, as far as I know, probably reduce it.
 
Keep in mind that bass impact isn't normally caused by deep bass, or boosted bass in general. It's caused by a boost in the mid-bass, around 80-110Hz. Grados, for example, have punchy bass but not much of anything under 50Hz. That's because they have a sudden mid-bass hump then roll off again into the lower mid-range. A neutral headphone can have bass impact if the bass response is fast, not distorted, a certain kind of resonance (not sure if it needs low resonance or too much resonance), and there's a slight emphasis on mid-bass to separate it from the mid-range.
 
You're not going to feel anything from headphone drivers below 10Hz. They don't push enough air.
 
Are we talking about a specific headphone?

 

[Parall3l]

Thanks for the replie, I'll check them out, although I didn't really understand it the first time I've seen them 

 The headphones I've I had in my mind is the STAX O2, LCD-2. They get a lot of praise for their apparently amazing bass.

 

[Head Injury]

They get praise for their deep and detailed bass, not necessarily impact. The LCD-2 only has impactful bass when the recording is right. It doesn't have a mid-bass hump, so the recording can't be mastered loud or the bass loses its peaks and impact.

 

[Parall3l]

Quote:

They get praise for their deep and detailed bass, not necessarily impact. The LCD-2 only has impactful bass when the recording is right. It doesn't have a mid-bass hump, so the recording can't be mastered loud or the bass loses its peaks and impact.

I see, thanks for clearing that up. I'm currently trying to understand those CSD graphs 

 

[jcx]

you also want to look at Fletcher-Munson curves http://en.wikipedia.org/wiki/Equal-loudness_contour - it looks like some headphones build in a "smile EQ" and can be expected to sound more tonally balanced at lower listening levels
 
listening level and frequency response are major determinating factors in "the sound" of a audio device

 

[Parall3l]

Quote:

you also want to look at Fletcher-Munson curves http://en.wikipedia.org/wiki/Equal-loudness_contour - it looks like some headphones build in a "simle EQ" and can be expected to sound more toanally balanced at lower listening levels
 
listening level and frequency response are major determinating factors in "the sound" of a audio device

Thanks for help, I've seen that graph a few time but have no idea what it was 

 Looks like you've just solved one of my many questions
 

 

[LFF]

Purrin is the guy you need to be asking.
 
His measurements are the most accurate I have seen and while FR might not reflect the sound 100% of the time, additional measurements like waterfall plots can help as well. I hope he chimes in as he knows a lot more about this scientific aspect of headphones than I do.

 

[purrin]

     Quote:

Thanks for the replie, I'll check them out, although I didn't really understand it the first time I've seen them 

 The headphones I've I had in my mind is the STAX O2, LCD-2. They get a lot of praise for their apparently amazing bass.

I see you are on a "quest for MOAR BASS!!!" So it's depends upon what you mean by "amazing" bass. Have you had a chance to hear the O2 or LCD2? If you are into "MOAR BASS" then you will probably be disappointed (unless it's the O2mk2 with its slightly bloated mid-bass.) People have differing opinions of what they consider good bass or amazing impact. The O2 (properly powered) and LCD2 have great extension with low distortion - this is why people think they have amazing bass. Also, lot of people don't realize that its the harmonics in bass instruments that significantly contribute to the impact aspect of bass.
 
If you want "MOAR BASS" in terms of volume, I would recommend the Denon AH-D2000/5000 and Darth Beyers. Their FR graphs reflect the bass-boost and non-linear FR that you would probably prefer.
 
Here's some "MOAR BASS" for you:

 

[Parall3l]

If I understood that graph correctly, thats a lot of bass 

 Thanks for the help, my problems are now solved