Planars... Am I missing something?
Apr 10, 2013 at 4:13 PM Thread Starter Post #1 of 14

Strangelove424

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I have been enjoying Grados and Beyers, but am tempted by all the forum talk about planar magnetics, and was curious about how my current DT880 would stack up against an in-my-budget HE-400... 
 
 

 
It looks like all the fun parts of the frequency spectrum (and the sections typically described as "recessed" in my DT880s) went cliff-diving on the HE-400s. Okay, so scratch that, maybe I should move my budget up a little more to the HE-500s...
 
 

 
Seriously? I mean, seriously? According to this graph, they look like the exact same headphone. I would be surprised if two different sets of DT880s measured that closely. 
 
Looking at the sine wave graphs, I don't really see the speed, precision, and fast decay attributed to planar magnetics either:
 
 

Looks like the DT880 actually has less resonance...
 
 
And the same, if not cleaner edges at 50Hz.

 
 

 
Distortion is better than Beyer on the low end, but as you can see a number of other phones are lower as well, so there's not anything special about planars here.
 
So am I missing something? Is there a special magic to planars that the measurements aren't capturing? I'm tempted to try them out, but nobody seems to be able to describe the planar sound in subjective terms clearly, and the graphs don't indicate that I'm missing out on much at all. If anyone has experience listening to both headphones, and can either confirm or contradict the graphs (even if using subjective albeit reasonably descriptive language) please chime in. 
 
Apr 10, 2013 at 4:37 PM Post #2 of 14
I don't think the HE-400 competes with the DT880 at all.  I personally think that the HE-400 is an over-rated headphone that sounds tinny and distorts easily.  I mean look at the frequency response alone which tells you there is a huge dip in the 2 kHz thru 5 kHz range which is smack dab in the middle of the audible range.
 
The distortion graph you reference for the DT880 is not right.  It must have been taken using a bad amp or something because it is much less prone to distortion than the distortion graph is showing.  I would use these graphs for the DT880 instead:
 
http://www.innerfidelity.com/images/BeyerdynamicDT88032ohm.pdf
 
The 600 ohm load which probably peaks around 800 or 900 Ohms is not being driven well by the amp causing the issues on the low end.
 
Here is the 600 Ohm DT880 from Innerfidelity:
 
http://www.innerfidelity.com/images/BeyerdynamicDT880600ohm.pdf
 
I guess one minor improvement the HE-400 may have over the DT880 is that the HE-400 is an open headphone allowing for more air movement and less resonator coupled distortion, but I still do not recommend the HE-400.  The HE-500 on the other hand is much better sounding and worth every penny.
 
If you are looking for an open headphone start with these:
 
1.)  Audio Technica ATH-AD900
2.)  Senneiser HD600/650
3.)  Philips Fidelio x1
 
I would shy away from headphones like Grado and AKG K701 or Q701 because they are unbearably bright.
 
Apr 10, 2013 at 5:10 PM Post #3 of 14
Those graphs look more accurate and reasonable.I was wondering why the DT880 would perform so well on everything else and then fall flat on distortion. Where did you find the PDF? I tried to look for measurements in Tyll's DT880 comparison but couldn't find the actual measurements.... Anyway, the list you supplied at the bottom is probably the direction I'll head if I don't go with planars. What I wanted was a relaxed, lush sounding headphone that still has the detail I am used to with the Beyers. Something to listen to late at night, when I just want to drift away. From subjective reviews, I gathered that the planar sound was essentially that - lush mids, but still alot of details. Looking at the graphs, I don't see that happening and your experience also confirms my suspicion that there's a lot of hype going around. I once tried an HD600 and enjoyed its warm tone, but found the details smeared and went with the DT880 instead. Can I expect HD-600-esq warmth from the HE-500, mixed with the resolution and detail of a DT880? That would be my perfect headphone, but if that's not realistic I think I'd rather rather pick up an HD600 to atleast put some variety in my setup and have a dedicated lush headphone for relaxation.
 
Apr 10, 2013 at 5:32 PM Post #4 of 14
Koss ESP-950 may cost 2x - but they get you solidly into ES performance - which are "planar drive" to a even higher degree
 
Apr 10, 2013 at 5:59 PM Post #5 of 14
I find the HD-650 and HE-500 similar in that they are both laid back and very easy to listen to.  Over long listening sessions they can sound a tad boring, but they are both excellent headphones.  I think the HE-500 has better detail than the HD-650 and if your budget allows the HE-500 is a great place to end up in the planar world.
 
Apr 10, 2013 at 6:09 PM Post #6 of 14
Quote:
Those graphs look more accurate and reasonable.I was wondering why the DT880 would perform so well on everything else and then fall flat on distortion. Where did you find the PDF? I tried to look for measurements in Tyll's DT880 comparison but couldn't find the actual measurements.... Anyway, the list you supplied at the bottom is probably the direction I'll head if I don't go with planars. What I wanted was a relaxed, lush sounding headphone that still has the detail I am used to with the Beyers. Something to listen to late at night, when I just want to drift away. From subjective reviews, I gathered that the planar sound was essentially that - lush mids, but still alot of details. Looking at the graphs, I don't see that happening and your experience also confirms my suspicion that there's a lot of hype going around. I once tried an HD600 and enjoyed its warm tone, but found the details smeared and went with the DT880 instead. Can I expect HD-600-esq warmth from the HE-500, mixed with the resolution and detail of a DT880? That would be my perfect headphone, but if that's not realistic I think I'd rather rather pick up an HD600 to atleast put some variety in my setup and have a dedicated lush headphone for relaxation.

 
The HE-500 has more low bass and less bass distortion than both the DT880 and HD-600. Innerfidelity, has a database of characterization sheets for the headphones that you are considering http://www.innerfidelity.com/headphone-data-sheet-downloads.
 
The DT880 amplifier voltage requirements depend on the impedance model one chooses. The 250 ohm version might be a good compromise. If interested in using tube amplifiers the 600 ohm version might be a better choice. The HE-500 might require a bit more current off the amp due to it's lower sensitivity numbers, but not as much voltage swing.
 
The HD-600 might be a little more laid back than the HE-500, with the HE-500 having more air to it. I find the HE-500 and the HD-600 similar sounding actually (aside from the low bass and air.) Both the HD-600 and HE-500 are less bright than the DT880.
 
Hope this helps.
 
If I had my choice between these three cans I would personally pick the HD600, but the HE-500 is a formidable headphone IMO, and it does some things better than the HD600.
 
Apr 10, 2013 at 6:13 PM Post #7 of 14
For starters it would help if you level matched the HE-400 graph like you did with the HE-500 graph.
 
Secondly, the couple of graphs you threw up wont give the whole story.  I'd personally take the HE-400 as an upgrade over the beyers.  The HE-500 has all of the traits as the HE-400 but is even more refined with flatter frequency response.  HE-400 is deliberately colored, so you'll either love or hate its presentation.  You can look at the battle of the flagship thread to get a good understanding of how they compare.  For what it's worth, I think the HE-400 is very warm, lush and laid-back.  Upon first hearing it I thought it was what the HD650 was supposed to sound like based off popular impressions of the HD650 on head-fi.  
 
Apr 10, 2013 at 9:14 PM Post #8 of 14
Quote:
 
The HE-500 has more low bass and less bass distortion than both the DT880 and HD-600. Innerfidelity, has a database of characterization sheets for the headphones that you are considering http://www.innerfidelity.com/headphone-data-sheet-downloads.
 
The DT880 amplifier voltage requirements depend on the impedance model one chooses. The 250 ohm version might be a good compromise. If interested in using tube amplifiers the 600 ohm version might be a better choice. The HE-500 might require a bit more current off the amp due to it's lower sensitivity numbers, but not as much voltage swing.
 
The HD-600 might be a little more laid back than the HE-500, with the HE-500 having more air to it. I find the HE-500 and the HD-600 similar sounding actually (aside from the low bass and air.) Both the HD-600 and HE-500 are less bright than the DT880.
 
Hope this helps.
 
If I had my choice between these three cans I would personally pick the HD600, but the HE-500 is a formidable headphone IMO, and it does some things better than the HD600.

 
I already own the 600 ohm DT880 and am using it with an Essence,STX, Little Dot MKIV, and Denon receiver. The Essence STX is most accurate, but tube amp sounds the best to me while still retaining alot of details that the STX delivers. The receiver actually sounds more "tube-like" than the tube amp, it's bass-heavy with a signifigant roll off at the highs, and it makes the Beyers sound quite dark, which is sometimes but not always enjoyable. As far as amps go, I really feel like I have that aspect covered and should be able to accept anything in the 60-600 ohm range with a variety of sound signatures to play around with. While the Beyers can change character from setup to setup, they still don't have the bloomy mids of the HD600 I tried a while back. Its those bloomy, lush mids I would like to achieve without sacrificing too much of the detail I've become accustomed to with my Beyers or my Grados. 
 
Judging by the general consensus, the HE500 sounds like it has the lush but still detailed personality I'm looking for, but none of the measurements from Headroom substantiate that. While I certainly don't buy headphones based on measurements alone (that would be like choosing meals based on flavor graphs) I'd still like to see some sort of correlation between measurement and experience. At this point, I am thinking that measurements aren't doing planars justice and there is something they are leaving out of the equation. I don't think there's much I can really decide on without listening to the HE500s and the HD600s side by side at this point. I am hoping that I find the HD600 the most appealing (just to save myself a few hundred over the HE500) but I'm fairly certain my next headphone will be one of these two. Thanks for everybody's insights, they were all very helpful.  
 
Edit: Just wanted to say I'm looking through Tyll's data sheet, and man oh man he takes good measurements. Not worlds apart in numbers from headroom's but just so so so much better, clearer, and more thorough. I didn't realize they were all in one place at his site, I guess you can blame that on lazy browsing tendencies and an avoidance of a seemingly boring although fundamental word like "resources" (which links to the measurements page). Regardless, thanks for the link, its quite a handy resource indeed.        
 
Apr 10, 2013 at 10:32 PM Post #9 of 14
One thing planars can do better than dynamics is bass. It's hard, if not impossible,  to find a dynamic headphone with flat, low distortion bass like the HE-400 or LCD2. 
 
As TMRaven said the HE-400 is like it is on purpose. The frequencies that it has a dip in are very harsh; it's meant for a warm, low fatigue listen that still has air and detail.
 
Apr 11, 2013 at 12:21 AM Post #10 of 14
On the topic of planars, is the amount power just something people have blown out of proportions? or current for that matter, I don't get why planars would favor current over voltage.
 
I heard, HE-500 needs at least 1W but I am a little suspicious as to what it is about this technology that needs that large of an amount of power. Seeing as an amp can consider them purely resistive, according to innerfidelity graphs, wouldn't it need just an ample amount of power?
 
Apr 11, 2013 at 12:47 AM Post #11 of 14
It's not really about the power as much as the quality.  Even in the HE-6's case, I've gathered that it might be more about the size and prowess of the transformer and other qualities within the amp moreso than just putting out as much wattage as possible.
 
Apr 11, 2013 at 12:53 AM Post #12 of 14
use the sensitivity number to get the power needed for a given SPL
 
for extreme audiophile cred you hold out for an amp that can push the cans to over 120 dB SPL without clipping - headroom you may never need - but it is a peak value that can be reached in live music  by percussion in small group jazz where you can be close to the players
 
 
orthodynamics are very inefficient because their magnetic circuit is poor, you have a lattice of magnets so the field lines graze the diaphragm - long air path weakens available magnetic field strength with very little of it occupied by conductor that generates force
 
regular dynamics have narrow radial gap, near saturation level mag field, high intensity field region well filled with voice coil
 
Apr 11, 2013 at 2:39 AM Post #13 of 14
Quote:
On the topic of planars, is the amount power just something people have blown out of proportions? or current for that matter, I don't get why planars would favor current over voltage.
 
I heard, HE-500 needs at least 1W but I am a little suspicious as to what it is about this technology that needs that large of an amount of power. Seeing as an amp can consider them purely resistive, according to innerfidelity graphs, wouldn't it need just an ample amount of power?

 
I agree with both what TMRaven and jcx said.
 
In regards to quality
 
Ideal amps should behave as either perfect voltage or current sources (depending on design goals.) They should have very high input impedance and very low output impedance. AFAIK, most headphones (perhaps not all) are designed with a perfect voltage source in mind. A perfect voltage source type amp should deliver voltage in perfect agreement with the source regardless of the load. The current delivered by the amp however would be a function of both the delivered voltage and the impedance of the headphone. In real life, AFAIK a perfect voltage source does not exist but can be approached. Add to that non-linearities and noise and you get quite a bit of different amp designs with different design goals and trade-offs. Innerfidelity also has some amp characterization charts available, and some discussion in this article: http://www.innerfidelity.com/content/headphone-amp-measurements-donealmost-aaaaarghh (I believe the "mW @ 1% THD" numbers need some work, but the "Volts @ 1% THD" seem to be fairly accurate.)
 
In regards to power
 
Going through the numbers usually helps. No guarantees here but hope this helps:
 
Consider the HD600 (http://www.innerfidelity.com/images/SennheiserHD600.pdf.) According to the characterization sheet, this headphone presents a 300 to 550 ohms load.
 
To get the sensitivity perform the following operation using the "Power Needed for 90d BSPL" number (variable x):
 
10*log10(10^(90/10)/x) = 97.696 dB SPL per mW.
 
These are rms numbers. As jcx said, some people would like the amp to be able to drive a headphone to peak 115 dB SPL given some high quality music material has relatively high dynamic range. To get the amount of power to do this perform the following operation using the sensitivity number above (variable x):
 
10^((115-x)/10) = 53.753 mW
 
Since P = V^2/R, this means that for 300 ohms, the amp needs to supply V = sqrt(P*R) = 4 V.
Since P = I^2*R, this means that for 300 ohms, the amp needs to supply I = sqrt(P/R) = 13 mA.
 
Now consider the HE500 (http://www.innerfidelity.com/images/HiFiMANHE500.pdf)
 
Using the above formulas we get:
 
86.904 dB SPL per mW (~ 10 dB less sensitivity than the HD600)
645.10 mW (to get 115 dB SPL) - Which I guess is close to 1W.
 
And therefore the amp needs to supply 5.5 V and 117.2 mA to get to cover 115 dB SPL peak power.
 
Note however that all these numbers are sort of representative as both impedance and sensitivity are frequency dependent on most headphones. Some people may also not need 115 dB SPL of peak power as they may listen at much lower volumes. Relaxing the 115 dB SPL requirement to 110 dB SPL yields 204 mW / 3V / 65.9mA requirements for the amp in the HE-500 case and  
17 mW / 2.25V / 7mA in the HD-600 case. 
 
With some amount of luck I hopefully didn't mess up the numbers 
biggrin.gif

 
Apr 11, 2013 at 3:16 AM Post #14 of 14
Quote:
It's not really about the power as much as the quality.  Even in the HE-6's case, I've gathered that it might be more about the size and prowess of the transformer and other qualities within the amp moreso than just putting out as much wattage as possible.

ok, so a good transformer is something to consider. I have the magni myself and I am wondering whether or not my HE-500 would benefit/improve from something like one of the Audio-GD or some larger schiit.
Quote:
use the sensitivity number to get the power needed for a given SPL
 
for extreme audiophile cred you hold out for an amp that can push the cans to over 120 dB SPL without clipping - headroom you may never need - but it is a peak value that can be reached in live music  by percussion in small group jazz where you can be close to the players
 
 
orthodynamics are very inefficient because their magnetic circuit is poor, you have a lattice of magnets so the field lines graze the diaphragm - long air path weakens available magnetic field strength with very little of it occupied by conductor that generates force
 
regular dynamics have narrow radial gap, near saturation level mag field, high intensity field region well filled with voice coil

Thanks for the explanation. It is really an interesting tech, at least for me. So I gather, I just have to take the planar magnetics for what it is; low efficiency headphones.
Quote:
 
 
 
I agree with both what TMRaven and jcx said.
 
In regards to quality
 
Ideal amps should behave as either perfect voltage or current sources (depending on design goals.) They should have very high input impedance and very low output impedance. AFAIK, most headphones (perhaps not all) are designed with a perfect voltage source in mind. A perfect voltage source type amp should deliver voltage in perfect agreement with the source regardless of the load. The current delivered by the amp however would be a function of both the delivered voltage and the impedance of the headphone. In real life, AFAIK a perfect voltage source does not exist but can be approached. Add to that non-linearities and noise and you get quite a bit of different amp designs with different design goals and trade-offs. Innerfidelity also has some amp characterization charts available, and some discussion in this article: http://www.innerfidelity.com/content/headphone-amp-measurements-donealmost-aaaaarghh (I believe the "mW @ 1% THD" numbers need some work, but the "Volts @ 1% THD" seem to be fairly accurate.)
 
In regards to power
 
Going through the numbers usually helps. No guarantees here but hope this helps:
 
Consider the HD600 (http://www.innerfidelity.com/images/SennheiserHD600.pdf.) According to the characterization sheet, this headphone presents a 300 to 550 ohms load.
 
To get the sensitivity perform the following operation using the "Power Needed for 90d BSPL" number (variable x):
 
10*log10(10^(90/10)/x) = 97.696 dB SPL per mW.
 
These are rms numbers. As jcx said, some people would like the amp to be able to drive a headphone to peak 115 dB SPL given some high quality music material has relatively high dynamic range. To get the amount of power to do this perform the following operation using the sensitivity number above (variable x):
 
10^((115-x)/10) = 53.753 mW
 
Since P = V^2/R, this means that for 300 ohms, the amp needs to supply V = sqrt(P*R) = 4 V.
Since P = I^2*R, this means that for 300 ohms, the amp needs to supply I = sqrt(P/R) = 13 mA.
 
Now consider the HE500 (http://www.innerfidelity.com/images/HiFiMANHE500.pdf)
 
Using the above formulas we get:
 
86.904 dB SPL per mW (~ 10 dB less sensitivity than the HD600)
645.10 mW (to get 115 dB SPL) - Which I guess is close to 1W.
 
And therefore the amp needs to supply 5.5 V and 117.2 mA to get to cover 115 dB SPL peak power.
 
Note however that all these numbers are sort of representative as both impedance and sensitivity are frequency dependent on most headphones. Some people may also not need 115 dB SPL of peak power as they may listen at much lower volumes. Relaxing the 115 dB SPL requirement to 110 dB SPL yields 204 mW / 3V / 65.9mA requirements for the amp in the HE-500 case and  
17 mW / 2.25V / 7mA in the HD-600 case. 
 
With some amount of luck I hopefully didn't mess up the numbers 
biggrin.gif

 
 

I used this calc to go from 87 to 115 dB
 
http://ampservice.de/splcalc.php?sensv1=87&spl1=115&pow1=2000&calculate=Calculate&lang=e
 
your calculation pretty much agree to roughly 650 mW :) but it says 2 W to go up to 120 dB 0.0 This headroom thing is pretty interesting, never even thought about it before. Thanks guys
 

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