[fjrabon]

  ^ Now I won't say this is a significant concern, but logically it is somewhat of a concern. Ultimately when you boost a frequency you feel is deficient, you are asking the headphone design to do what it can't do anyway, or at least not at the amplitude you want. The headphone for better or worse has design parameters so if you go beyond them, the odds of improving the sound are low whereas the odds of negatively impacting the sound (how audible the effect will be would depend of course). Now I suppose if the material itself was quite deficient itself in the frequency being adjusted that does allow some room for gain before hitting the performance wall. I think of well mastered 70s music that is bass shy, that material you should be able to plump up a little.

I think there are a couple of issues tied together in what you're saying.
 
1) adding gain to the pre-amplified signal through EQing up.  This will almost always induce distortion, especially if it's done to the bass, which bass needs substantially more power to boost.  a 2dB boost to 32Hz takes something like 1000 times the power that a 2dB boost to 3.2 kHz does.  This is basically always a bad idea.  You may not be able to notice it, but it is simply inducing distortion, the signal output is going to require more than line level power, and EQ sections are AWFUL at doing that.  They're not made to do that, it's nto their function (some dedicated EQ units do have a small amplifier built in to handle this, but they're still not very good at it, and you're double amping then too, which is a bad idea).  
 
EQ isn't an active bass boost circuit.  If you EQ by pulling down, you don't overload the pre-amplified signal, and then you can let your power amp do the work of providing the power the signal needs, which is the amplifier's job, and it's very good at it compared to the EQ section of the signal.  This issue has nothing to do with the headphone.  You could have a theoretically perfect headphone (or speaker with subwoofer) and this would cause issues, because it's a distorted signal before it ever gets to the headphone.  At best the headphone will be reproducing a distorted signal.  At worst the headphone gets screwy because it's being fed a distorted signal and will make it sound EVEN WORSE.  Now, again, at low levels this may be imperceptible, especially with headphones that don't reproduce sub bass accurately to begin with.  A lot of people think distorted sub bass sounds good anyway.  But as a technical matter, it's introducing distortion into the signal, and if you care about feeding your headphones a clean signal this should always be avoided.
 
2) a headphone's ability to take higher levels of power at lower frequencies.  I think this is what you're getting at, and there's some truth.  SOme headphones, even if you EQ them properly, and the signal being fed to them is pure, and the amp has plenty of head room to then send a distortion free EQd signal, they can't accurately reproduce the added power to the lower frequencies, and this is what we call bass bloat and bass wooliness.  My AD700 are a great example of this.  The AD700 is an incredible headphone, but it is fairly extremely rolled off in the bass.  So, for years, people have been trying to fix this.  Everything from putting cellophane around the pads (yes, seriously, I've seen people advocate cellophane wrapping the pads.  But most commonly people EQ them.  THis was my first reaction too.  But the AD700 is rolled off for a reason, the driver simply doesn't have the horsepower to take a lot of bass, and when you try to EQ it and then send it a bassy heavy signal, it gets super bloated, the soundstage collapses, the detail collapses, and you go from a great, but bass light headphone to a cheap sounding headphone with average bass quantity.  Contrast that with the HE400i.  It's planar design means you can EQ in a TON of bass (again, by EQing everything else down, and then using the power of the amp to drive the extra bass power needs) it handles it easily.  You can make the HE400i sound basically however you want with EQ, if you're willing to do it right and have a decently powerful amp.  With a simple EQ adjustment you can make it sound almost exactly like a HE400, or a LCD or whatever.  To a lesser extent this is also true of the SRH840, because it's a professional monitoring headphone and it's designed to be able to take all kinds of frequencies fed to it.  
 
It is something of an irony that the better headphones, those that tend to need EQ less, are the headphones best able to handle heavy EQing.  The lower quality headphones, many times, if you try to "fix" them with EQ, they just end up bloated, lose resolution, imaging, etc.  

 

[Sonic Defender]

^ I hear you brother (no pun intended). I'm not sure that when done modestly that EQing is very degrading to sound quality. I like you suggest when I EQ, I always EQ down, and I use a parametric EQ at that. I did come across a very good technical article at an audio engineering site for actual engineers that essentially said the notion that EQing up is a negative is quite overblown. Essentially the author was demonstrating that within the sound envelop if there is room for the gain it will be fine, distortion occurs when the gain is over-applied. Regardless, I think your advice is quite prudent, EQ down rather than up.

 

[Headphone4Life]

I have to say that I do notice a bit of a difference when EQ'ing all the levels down a little and keeping the bass flat. It doesn't sound as bloated as it did when pumping the bass up a few db's, thanks for the tip.

 

[fjrabon]

  ^ I hear you brother (no pun intended). I'm not sure that when done modestly that EQing is very degrading to sound quality. I like you suggest when I EQ, I always EQ down, and I use a parametric EQ at that. I did come across a very good technical article at an audio engineering site for actual engineers that essentially said the notion that EQing up is a negative is quite overblown. Essentially the author was demonstrating that within the sound envelop if there is room for the gain it will be fine, distortion occurs when the gain is over-applied. Regardless, I think your advice is quite prudent, EQ down rather than up.

like you said, it primarily depends on the "head-room" before you hit what a maxed out line level signal is.  Now, there are two issues that make this a bigger issue than it might seem in some ways of analysis.  1) people usually do this most with bass.  Bass can QUICKLY eat up any headroom in the pre-amplified signal, because it requires so much power.  Eqing up the treble almost never actually causes a problem. EQing up sub bass, even 3 dB can very easily induce distortion.  2) so many modern recordings are so heavily compressed and brickwalled right at the limits of a maxed out line level signal to begin with that almost anything tips them over the edge, that's what people call the loudness wars, they pushed the music to where you're essentially at max line level AT ALL TIMES.  The original mastering of Allman Brothers live at the fillmore east?  Plenty of room, and you could get away with some EQing up.  Oasis What's The Story Morning Glory?  add in some bass there and you're basically at distortion before you even get to 2dB.  

 

[Thazzz]

 
I think there are a couple of issues tied together in what you're saying.
 
1) adding gain to the pre-amplified signal through EQing up.  This will almost always induce distortion, especially if it's done to the bass, which bass needs substantially more power to boost.  a 2dB boost to 32Hz takes something like 1000 times the power that a 2dB boost to 3.2 kHz does.  This is basically always a bad idea.  You may not be able to notice it, but it is simply inducing distortion, the signal output is going to require more than line level power, and EQ sections are AWFUL at doing that.  They're not made to do that, it's nto their function (some dedicated EQ units do have a small amplifier built in to handle this, but they're still not very good at it, and you're double amping then too, which is a bad idea).  
 
EQ isn't an active bass boost circuit.  If you EQ by pulling down, you don't overload the pre-amplified signal, and then you can let your power amp do the work of providing the power the signal needs, which is the amplifier's job, and it's very good at it compared to the EQ section of the signal.  This issue has nothing to do with the headphone.  You could have a theoretically perfect headphone (or speaker with subwoofer) and this would cause issues, because it's a distorted signal before it ever gets to the headphone.  At best the headphone will be reproducing a distorted signal.  At worst the headphone gets screwy because it's being fed a distorted signal and will make it sound EVEN WORSE.  Now, again, at low levels this may be imperceptible, especially with headphones that don't reproduce sub bass accurately to begin with.  A lot of people think distorted sub bass sounds good anyway.  But as a technical matter, it's introducing distortion into the signal, and if you care about feeding your headphones a clean signal this should always be avoided.
 
2) a headphone's ability to take higher levels of power at lower frequencies.  I think this is what you're getting at, and there's some truth.  SOme headphones, even if you EQ them properly, and the signal being fed to them is pure, and the amp has plenty of head room to then send a distortion free EQd signal, they can't accurately reproduce the added power to the lower frequencies, and this is what we call bass bloat and bass wooliness.  My AD700 are a great example of this.  The AD700 is an incredible headphone, but it is fairly extremely rolled off in the bass.  So, for years, people have been trying to fix this.  Everything from putting cellophane around the pads (yes, seriously, I've seen people advocate cellophane wrapping the pads.  But most commonly people EQ them.  THis was my first reaction too.  But the AD700 is rolled off for a reason, the driver simply doesn't have the horsepower to take a lot of bass, and when you try to EQ it and then send it a bassy heavy signal, it gets super bloated, the soundstage collapses, the detail collapses, and you go from a great, but bass light headphone to a cheap sounding headphone with average bass quantity.  Contrast that with the HE400i.  It's planar design means you can EQ in a TON of bass (again, by EQing everything else down, and then using the power of the amp to drive the extra bass power needs) it handles it easily.  You can make the HE400i sound basically however you want with EQ, if you're willing to do it right and have a decently powerful amp.  With a simple EQ adjustment you can make it sound almost exactly like a HE400, or a LCD or whatever.  To a lesser extent this is also true of the SRH840, because it's a professional monitoring headphone and it's designed to be able to take all kinds of frequencies fed to it.  
 
It is something of an irony that the better headphones, those that tend to need EQ less, are the headphones best able to handle heavy EQing.  The lower quality headphones, many times, if you try to "fix" them with EQ, they just end up bloated, lose resolution, imaging, etc.  

 
I never thought that....

 
then...what do you think if i boost the bass with the micro iCAN to the 400i?
Could be a good idea to increase the lows?
 
I've always been a little basshead

 

[Headphone4Life]

like you said, it primarily depends on the "head-room" before you hit what a maxed out line level signal is.  Now, there are two issues that make this a bigger issue than it might seem in some ways of analysis.  1) people usually do this most with bass.  Bass can QUICKLY eat up any headroom in the pre-amplified signal, because it requires so much power.  Eqing up the treble almost never actually causes a problem. EQing up sub bass, even 3 dB can very easily induce distortion.  2) so many modern recordings are so heavily compressed and brickwalled right at the limits of a maxed out line level signal to begin with that almost anything tips them over the edge, that's what people call the loudness wars, they pushed the music to where you're essentially at max line level AT ALL TIMES.  The original mastering of Allman Brothers live at the fillmore east?  Plenty of room, and you could get away with some EQing up.  Oasis What's The Story Morning Glory?  add in some bass there and you're basically at distortion before you even get to 2dB.  

I never looked at it like that before but that makes a lot of sense.

 

[dtabn]

I wish I waited a little bit longer to buy my 400's, they are way too heavy on the high end, and these seem to deal with that issue.  Oh well, EQ helps out a bit....

 

[fjrabon]

I never thought that....:rolleyes:

then...what do you think if i boost the bass with the micro iCAN to the 400i?
Could be a good idea to increase the lows?

I've always been a little basshead

I have no idea how it works in that unit, but how most bass boosts work is essentially a low pass filter and a small gain boost to get equal volume. I.e. It cuts everything below maybe 250 Hz, and then adds some gain to the resulting signal. It's more or less like a "quick eq" adjustment. I generally prefer hand tailoring my "bass boost" with eq, but this is sort of like doing that with a preset.

 

[Modular]

  2) so many modern recordings are so heavily compressed and brickwalled right at the limits of a maxed out line level signal to begin with that almost anything tips them over the edge, that's what people call the loudness wars, they pushed the music to where you're essentially at max line level AT ALL TIMES.  The original mastering of Allman Brothers live at the fillmore east?  Plenty of room, and you could get away with some EQing up.  Oasis What's The Story Morning Glory?  add in some bass there and you're basically at distortion before you even get to 2dB.  

This is the bigger issue and there are tons of threads on car audio forums about how to properly set gains as a result. At the end of the day, using a 0db track and adjusting EQ down is the only way to be sure you aren't just adding distortion.

Distortion is the real enemy. Not only is it likely to damage your equipment, it is way worse for your hearing than loud volumes (also bad of course). The reason that headphone started to sound like crap with EQ being applied is because of the electrical limitations of the circuit (distortion) and the physical limitations of the driver.

Good discussion! I am loving my he400i's so far. Driving them with my Project Sunrise and Behringer UCA202 DAC and I am pretty sure they are all I am going to need in a headphone for quite some time. Now the DIY bug has bitten me hard again and I finally havenl the motivation to finish my Gamma2.

It is going to be a great winter listening season!

 

[Sonic Defender]

^ Everybody agrees (in essence) let common sense prevail. If the music is contemporary, heavily compressed music, there really is no room for gain as there is no head-room left (dynamics) to work with. In a case like that, live with the sound or do EQ cuts around the frequencies you actually want to emphasis. Otherwise, if there is dynamic room left to work with and you really do feel a gain should be applied to a frequency or frequencies, then do so in small, modest steps, and please use a parametric EQ where possible. Almost as a rule I never bother to EQ. If the material is so bad I won't bother playing it, and if the headphone is seriously deficient or overblown that it really needs EQing, I'm more likely to replace it. EQing at first can be fun to play with, but ultimately it consumes way too much time that I could be using to listen to music.

 

[Danthrax]

I just want to confirm that this is what the 400i drivers are supposed to look like because I thought I saw people with a different magnet array on theirs I just want to be sure there wasn't a mixup in the factory and I ended up getting the wrong drivers. http://imgur.com/LCoIZBC

 

[fjrabon]

  I just want to confirm that this is what the 400i drivers are supposed to look like because I thought I saw people with a different magnet array on theirs I just want to be sure there wasn't a mixup in the factory and I ended up getting the wrong drivers. http://imgur.com/LCoIZBC

that's what mine looks like

 

[Danthrax]

Awesome now I just have to find people to buy all of my other headphones and I'll be perfectly happy with these

 

[Aradea]

50% off. Quite a steal for these phones.

No further info eh? 

 

[canthearyou]

I just want to confirm that this is what the 400i drivers are supposed to look like because I thought I saw people with a different magnet array on theirs I just want to be sure there wasn't a mixup in the factory and I ended up getting the wrong drivers. http://imgur.com/LCoIZBC

Mine look completely different.