Frequency response graph can be very misleading to say the least
Jul 28, 2011 at 5:51 PM Post #16 of 38

nick_charles

Headphoneus Supremus
Joined
Feb 26, 2008
Posts
3,180
Likes
334


Quote:
You guys are awsome! I'm learning so much.
 
The waterfalls seem to show a lot of bass decay in Sony and near 4 kHz decay in Koss and that seems to correlate to the strong bass in Sony and near 4 kHz peak in Koss that I could hear/measure.
 
But would decay would be audible when using constant signal from frequency generator?
 
Is decay inherently bad in transducers?
 
Thanks!



Ideally the decay should accurately mimic the decay in the original source neither extending it nor truncating it. Think about an unamplified double bass playing a single note , only the first few cycles will be close to maximum amplitude then the peaks will get smaller and smaller until eventually the string stops oscillating.  if you are still hearing the tone 5 seconds after the string has come to rest something is wrong similarly if the transducer stops vibrating while the note (source) is still ringing strongly you have an excessively overdamped transducer
 
http://www.ht-audio.com/pages/SpeakerBasics.html
 
 
 
Jul 28, 2011 at 6:08 PM Post #18 of 38

maverickronin

Headphoneus Supremus
Joined
Apr 5, 2010
Posts
7,390
Likes
420
Quote:
I wonder if the Japanese used a head with mics inside silicon ear canals like Tyll did at Headroom (and still does at Innerfidelity)


I'm pretty sure he doesn't.  I've read someone else saying he uses a generic acoustic coupler.  His FR graphs look a little off compared to Tyll's at both Headroom and Innerfidelity.
 
I don't think that the waterfall plot should be effected too much, but I'm not an expert at this...
 
Jul 28, 2011 at 7:10 PM Post #21 of 38

maverickronin

Headphoneus Supremus
Joined
Apr 5, 2010
Posts
7,390
Likes
420
I see something like that on the distortion chart.
 
Never heard the V6 myself though I love my KSC75.
 
Jul 28, 2011 at 7:33 PM Post #22 of 38

jack black

New Head-Fier
Joined
Jul 26, 2011
Posts
30
Likes
11


Quote:
Ideally the decay should accurately mimic the decay in the original source neither extending it nor truncating it. Think about an unamplified double bass playing a single note , only the first few cycles will be close to maximum amplitude then the peaks will get smaller and smaller until eventually the string stops oscillating.  if you are still hearing the tone 5 seconds after the string has come to rest something is wrong similarly if the transducer stops vibrating while the note (source) is still ringing strongly you have an excessively overdamped transducer
 
http://www.ht-audio.com/pages/SpeakerBasics.html
 
 




I don't know about that. The transducer should mimic what mike is hearing. if the note is still ringing, the mike will keep sending the signal to the transducer. It's not like we are plucking the transducer itself.
 
Jul 28, 2011 at 7:43 PM Post #23 of 38

jack black

New Head-Fier
Joined
Jul 26, 2011
Posts
30
Likes
11
OK, I found a decent description of decay here: http://www.ecoustics.com/electronics/products/articles/131062.html
 
Looks like it's bad in midrange (coloration) and boosts bass in low range. Please feel free to correct me if I misunderstood.
 
Jul 28, 2011 at 8:22 PM Post #24 of 38

Jack C

Previously known as Jack-Micca
Member of the Trade: TekFX
Joined
May 20, 2010
Posts
573
Likes
60
For accuracy, the reproduction system should have as much decay as possible. That is, once the signal is removed, the cone should stop moving as soon as possible.
 
If there was any prolonged decay in the original source, it should have already been captured in the recording.
 
The best example would be recording music in a hall, where the extended reverb is a form of prolonged signal decay. This would be captured by the recording microphone, and the speaker that is playing it back should not add any further decay.
 
Jack
 
Jul 28, 2011 at 10:11 PM Post #25 of 38

khaos974

Headphoneus Supremus
Joined
Mar 19, 2008
Posts
2,085
Likes
117
You may simply be hearing a different frequency attenuation due to the difference of impedance between the 2 headphones.

The impedance vs frequency curve of those 2 headphones have different peaks, and both are fairly low impedance, so unless you are using an amp with a very low impedance output, you are bound to hear the impact and end up with a frequency curve different from what was measured on Headroom.
 
Jul 29, 2011 at 3:55 AM Post #27 of 38

Shike

Headphoneus Supremus
Joined
Feb 1, 2005
Posts
1,888
Likes
71
What are you plugging the headphones into?  If it has high output impedance the FR of the headphones will be different based on that (khaos said this, it's worth repeating).
 
Jul 29, 2011 at 10:57 AM Post #30 of 38

jack black

New Head-Fier
Joined
Jul 26, 2011
Posts
30
Likes
11
I used both laptop soundcard (that sounds decent to my ear) and my old, but mid-range 5.1 receiver set to Stereo without any DSP. Don't know about the actual impedance values in the amps.
 
I'm now convinced that the sound decay is the issue, as the Japanese graphs show a huge difference between these two phones.
 
In the meantime, I did some more searches that discovered this old thread on this very forum with similar critique of FR graphs: http://www.head-fi.org/forum/thread/463529/frequency-response-graphs-are-a-curious-thing
 
Well, it's a learning process for me and thanks for educating me.
 

Users who are viewing this thread

Top