HiFiman HE-500 (HE as in High End) please post your impressions. . loan pair for UK pg. 28. - Page 179

I don't really get why a +1 watt amp is recommended when you will never use any more than 20mW in peaks (i doubt). Is it due to the low impedance, and the resulting distortion from the amp at say a couple of milliwatts?

Does anybody know in the first place, I have never found a reasonable explanation.

Good question.

 

Just to add, my most powerful amp sounds slower than a much less powerful one that I have.

Idont think its power perse thats the main key here with the he500... The amp just have to pair well... My amp for instance..its way less powerfull then a lyr..but to my ears ismuch better paring with the he500. But i have to admit..planars dor love a bit of power..but it has to be quality power.

If I remember correctly, Hifiman recommends an amp that can put out 2-3 watts, 1 watt at least, and I have heard it mentioned a lot

Of course, but a reasonable explanation why at least 1watt is required?  

[/INDENT]
Check this thread out for explanation..well..sort off

http://www.head-fi.org/t/606260/orthodynamic-headphones-voltage-and-watts

And another thing..i actually contacted hifiman (head direct) customer service myself by mail with the question what i needed to drive the he500 well..as i wanted to buy one and was afraid in spending to much on a amp also..and they replied me with at least 1watt.. So i guess they must have a reason to say that being the manufacturer.
Edited by hifimanrookie - 1/22/13 at 1:42am

http://www.innerfidelity.com/content/innerfidelity-headphone-amp-measurement-program-update-july-2012

 

Basically, the O2 amplifier is able to feed the HE-500 with approximately 400mW, almost without distortion. Even at 100dB the HE-500 would only use some 50mW. At 110 dB the O2 would distort. Say you are listening to some really quiet recording at 75-80dB on average with peaks going up to 105-110dB it could pose a problem. But who does that? :P

Why does high output impedance tend to alter the bass response, and not the rest of the FR? Is it because the impedance tend to be higher in the bass regions?

 

When generating bass the driver needs to move more than with higher frequences. When damping factor is low the amplifier will have a harder time getting the driver back and forth. This should be more noticeable in lower regions because of the driver moving longer away from its reference point.

20mW as an average power is already very loud, but music is not like continuous test signals (which are used to measure output power, impedance, and so on).

Attacks, for instance, create a surge current draw that (relatively) weak amplifiers cannot provide (relative to the average power of the music). As a result, the attack is not sharp/tight and the overall impact is tamed. As a side effect, the imaging (instrument separation / overall definition) is decreased due to the lack of transient in higher frequencies (which the planar headphones are loved for) and the bass becomes bloomy.

The more you crank up the volume, the less headroom you get and the sound becomes blurry/bloomy and all the side effect that comes with it (harshness, ...).

 

As a matter of fact, powerful amplifiers have more headroom than weaker ones and thus, do a better job overall at reproducing transients (treble) and slam (bass) and have the headroom to retain these qualities at higher volumes.

 

The HE-500 is rated at 89dB, which, for headphones, is still really low.

 

The DT-880, for instance, is rated at 96dB. It's not the most efficient phone either but it already requires 5x less power than the HE-500.

 

Planars have an advantage however: their impedance is (almost) purely resistive and quite low which makes for an easy load to drive (in the amp's "point of view").

Edited by Clemmaster - 1/22/13 at 3:00am

So... Basically you are saying that weaker amps in general can't deliver current fast enough to ensure good transient response and precise and immediate  signals.

There's many variables that could cause effects here beyond what has been mentioned... for example, I've seen anecdotal evidence that the he-500 efficiency can vary widely from one set to another (at least the resistance can, I'm assuming the efficiency would change as well). While the listed efficiency for these cans is 89db, if it could vary to even 85db, loud peaks could easily suck up a full watt of power (85db/mw @ 115 SPL = 1000mw). That's really bloody loud, but I'm guessing HiFiMan is telling us the power we could need to make sure the cans can perform for any potential usage and not just an average listening volume (not to mention lower dynamic range recordings).

An amplifier only putting out 300-500mW, should still be able to sound good? 89dB/mW and 'normal' listening level with 'normal' recordings should pose no problems, but worst case scenario you could have problems with an amp not putting out 1W, I guess...

 

Because Dr Fang himself stated about 1 watt should do it.

 

(though in an experiment with several different amps, I found the HE500 sounded fine from a tiny little Fiio E10 that outputs a 10th of that power, plenty of bass, mids were great, sounded pretty dynamic to me... so I don't know... and it clipped like a limping horse from an OTL LDMK III ... awful.. and I currently power from a 50 watt amp... so again, who really knows what's truly needed here...)

 

 

Very best,

Edited by MalVeauX - 1/22/13 at 5:29am

Not sure it's all power-related but last night I switched from my Lake People G100 (1806mW/40ohm) to my integrated Rega Mira 3 (61W/8ohm).

Control and 'sense of air' reached another level. The digitally controlled volume control works very well with HE-500. Volume knob is between 10 and 11'o'clock. With my Elac 207 speakers it's usually between 11 and 12'o'clock.