HD800 being "picky" with amps myth
Aug 4, 2014 at 10:35 PM Post #226 of 323
Damping factor discussion is now here: http://www.head-fi.org/t/729314/damping-factor
 
Aug 5, 2014 at 11:52 AM Post #227 of 323
What were the applied EQ parameters?
 
The amplitude for a given frequency band might just be hitting the -35dB cutoff point more quickly if it's attenuated. Just speculating since the context behind those charts in particular are rather vague in terms of methodology and context.
 
I've seen a HD 800 attenuated pretty much 6dB above 4KHz where the waterfall behavior down to -70dB didn't change significantly compared against some simple foam liner that attenuated just 2-3dB but reduced measured ringing.
 
Aug 5, 2014 at 2:36 PM Post #228 of 323
  What were the applied EQ parameters?
 
The amplitude for a given frequency band might just be hitting the -35dB cutoff point more quickly if it's attenuated. Just speculating since the context behind those charts in particular are rather vague in terms of methodology and context.
 
I've seen a HD 800 attenuated pretty much 6dB above 4KHz where the waterfall behavior down to -70dB didn't change significantly compared against some simple foam liner that attenuated just 2-3dB but reduced measured ringing.

That's valuable knowledge.. Question is how much the CSD changes with volume, one could perhaps cross match that with the other measurements /w EQ/mods.
 
Aug 5, 2014 at 3:55 PM Post #229 of 323
  What were the applied EQ parameters?
 
The amplitude for a given frequency band might just be hitting the -35dB cutoff point more quickly if it's attenuated. Just speculating since the context behind those charts in particular are rather vague in terms of methodology and context.
 
I've seen a HD 800 attenuated pretty much 6dB above 4KHz where the waterfall behavior down to -70dB didn't change significantly compared against some simple foam liner that attenuated just 2-3dB but reduced measured ringing.

 
Compare the level of the signal at 0 ms and the level of the signal following 0 ms. If there was a larger drop between them with EQ then you can assume the decay to potentially have been faster. I say this because it happens in all of those graphs.
 
On the second point, the idea isn't so much to reduce ringing by cutting some part of the spectrum by that many dB. The idea is more that the closer you get the response to neutral, the better your decay. So if your neutral is -3 dB off and you overshoot your EQ by 3 dB, you're not there. What would be more relevant is if you matched the modded response with EQ more or less exactly before comparing.
 
Aug 5, 2014 at 4:02 PM Post #230 of 323
Compare the level of the signal at 0 ms and the level of the signal following 0 ms. If there was a larger drop between them with EQ then you can assume the decay to potentially have been faster. I say this because it happens in all of those graphs.
 
On the second point, the idea isn't so much to reduce ringing by cutting some part of the spectrum by that many dB. The idea is more that the closer you get the response to neutral, the better your decay. So if your neutral is -3 dB off and you overshoot your EQ by 3 dB, you're not there. What would be more relevant is if you matched the modded response with EQ more or less exactly before comparing.

Of course. I'm just curious as to what parameters were applied in the EQ'd chart to better understand what might be accounting for the change in decay behavior. Without those parameters, it just looks like a picture to me (it does a good job at showing "what" but doesn't even hint at "how").
 
How might nonlinear characteristics change with the application of linear EQ in any form? Just curious.
 
Aug 5, 2014 at 4:35 PM Post #231 of 323
The graphs are old enough for the EQ curves to be lost. What I'd propose is that if you can match the decay of mods with EQ by matching the frequency response, you either have incorrect measurements or need only ask how mods change the decay to explain how EQ does it, as well.
 
I've only tested for decay, so can't say much apart from it.
 
Aug 5, 2014 at 5:23 PM Post #232 of 323
well if a mod changes the air flow, it might very well impact the ringing. and would certainly impact the low frequencies in some ways. I'm thinking close vs vented type or change.
 
Aug 6, 2014 at 9:26 AM Post #233 of 323
If EQ and mods sharing principles is one hypothesis, one could take the opposite view and consider the outcome - the waveform at the eardrum. If the HD 800 mod, as JaZZ says, functions by reducing reflections, it might be put forward that EQ (whether 'normal' or convolution) manipulates the reflections to produce a result at the eardrum identical to the mod. JaZZ does argue that you can't eliminate cup reflections with frequency response modification alone, but it doesn't seem much of a stretch to suggest that waves do have innately the ability to eliminate each other.
 
Aug 6, 2014 at 2:54 PM Post #234 of 323
I guess it must be the tubes. Luckily, those are easily replaceable.


Exactly. It's all about the 'Tubes!' They lose their 'vacuum' quite quickly. Even the highest quality rectifiers and power tubes like Jenson lose their peak performance with in about 1300 hrs. Easily replaceable yes, but overtime the overall capacity of the tube amp itself loses some ground cause it runs very very hot to be effective. This is hard on the circuitry over extended periods of time. Things like transformers and transistors have to be looked at after a few years depending on how much you use it.
Just remember to always warm that sucker up before using it. Can be so damaging.
 
Aug 9, 2014 at 1:07 PM Post #235 of 323
Here is a question for those that likes to explain things scientifically.  What do you believe an amp like BottleHead Crack tube amp does to the HD800 for lot of folks to prefer it?
 
Aug 9, 2014 at 1:21 PM Post #236 of 323
  Here is a question for those that likes to explain things scientifically.  What do you believe an amp like BottleHead Crack tube amp does to the HD800 for lot of folks to prefer it?


Has anyone done any measurements on the crack?
 
Cheers
 
Aug 9, 2014 at 6:20 PM Post #238 of 323
120ohm output impedance that make HD800 warmer

Lots of people seem to think it sounds good, and there is good reason for that I should not repeatedly bring up in the 800 thread that could be too much of the truth to take in.  Curious what the tube's output impedance is doing to the drivers to warm up the sound.  I was thinking the lack of damping contrast to the SS amps, it's loosening the driver causing the pleasant distortion to cause the fuller or warm sound.  This seems to be much in need based on what I've heard of the 800 out of a few SS amps.  I haven't tried tubes to hear how it changes the sound.  It depends on if the neutral in the lows is what the listener is ok with or they are used to more bass.
 
Aug 23, 2014 at 1:34 AM Post #239 of 323
This info should really belong in this thread.
 
Quote:
  Ok, so I've looked into this in Audacity and looked into the spectrographs, and these show why the sound is harsher for pop music(top two) and audiophile recordings(bottom two).  Notice the red in the treble area is more prominant for the pop music vs the audiophile recording.  The redder the color, the waveforms have higher peak.
 

 

 

 

 
FR of HD800 (notice the treble peak region).  Now, why would people say the 800 sounds harsh?  
redface.gif
  Also explains genre listening preference of this type of headphone, and why only certain genres are preferred.
 

 

 
Oct 21, 2014 at 11:08 PM Post #240 of 323
I would love to have fellow head-fi'rs opinions on this product....http://thesubpac.com/order/subpac-s1/ being intergrated with in a quality soundchain (amps/DACS). I am tempted to buy this and pair it with my HD 800's along with my quality sources.
Frequency response is 5-125 Hertz. Don't think it's a lame product.
Low end frequency responses are accurate.
 

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