High End Headphone Myth

Well you heard the MS1/SR125? They completely trounced my HD580s from an iPod.

The myth is not a myth. The reason behind people saying it is that you would get better sound from an easier to drive headphone like the AT AD series or Grados than going with a Senn and under-powering it.

There are a few generalizations in there that are impossible to truly agree or disagree with so to play devil's advocate, I will just pick on them.

Lets start with science - according to the frequency response graph of the HD600, the voltage swing required to retain a consistent response to all frequencies (mostly the bass as it requires considerably more voltage) is about +/- 8V at fairly loud listening levels. An iPod will output 3.7V... which simply means you cannot get accurate response from the headphones using only that player.

Of course, whether you think the headphones sound "weak and boring" is another story altogether, and nobody can tell you that what you hear is in fact "boring", that is personal preference and if you like it, enjoy it.

As a general rule, nobody said that expensive headphones require an amp or that cheaper headphones don't. That does not depend on price at all, it only depends on impedance and sensitivity of the headphone.

The last part really blows the $150 headphone + $200 amp argument to crap, it really depends on what headphone.

When I first started here 8 years ago, I ordered a Total Airhead and the Sennheiser HD580 together. I was sure it would be worth it to drop the extra $200 to drive the headphones "right". I used the line-out from my panasonic PCDP (yeah, I know it's not a hifi source). The excitement died down quick - the combo sounded totally bland, a major disappointment. Then I thought to try driving the HD580 directly from my PCDP headphone jack - THAT was a revelation. I was finally hearing all the things I had EXPECTED I would hear from the excellent HD580. It was very musical and enjoyable. I never warmed up to the Total Airhead.

By now I've heard plenty of "real" hifi sources/headphones/speakers/amps, and I still think the sound from that simple HD580/PCDP system was a cut above what any lesser headphone would be capable of - well worth the cost of the HD580. I still think that HD580/Total Airhead/PCDP sounded far, far worse.

For a true enthusiast, yes - the expense of a QUALITY amp is warranted. For someone else merely wanting a nice upgrade over mediocre sound? Likely not, depending on source...

Sounds good to me; get the best headphones you can, and you will like them. Then later, get them a proper amp and you will begin to appreciate them in a whole new light. Then upgrade your source, tweak your cables, etc. Very rarely is someone "done" in this hobby.

Took the words right out of my mouth.

I don't get the math here. It's damping factor - achieved through a low output impedance from the amp - that will keep the resultant HD600 frequency response from severely "riding" its impedance curve. Output impedance just needs to be sufficiently lower than 300 ohms (30-60 ohms or less, ideally), for the HD600. The max voltage output doesn't tell you that, it only gives you a clue how loud you can get before you run out of headroom (assuming adequate current drive).

So at 3.7V, for the 300-ohm HD600 you have:
P = V^2/R = 45.6 mW

Aren't the HD600 103dB/mW (estimate, going from memory)?
So that gives you 103dB + (10*log_10(45.6))dB = 119.59 dB!!
Even if that's just for max peak, 120dB should be sufficient for anyone. Now, how the amp behaves near its peak voltage is another matter - but nothing in the presented numbers here suggests a severe limitation driving the HD600 with 3.7 volts.

Like I said, I don't get the math (or rather, the conclusion from 2 numbers) you've presented.

That's when you'll have to use some math (something I'm not a fan of usually ).

Lets first review this article, then take a look at these graphs for HD600:


Now the math comes in... and I leave the room...

Ok...that still doesn't address why source voltage output of 3.7, alone, would be limiting in any meaningful way in scope of the HD600. What are you talking about??

As for amp output impedance, the impedance curve pictured there is actually VERY amp friendly. Even that big peak is under 2x the nominal impedance, and (of greater importance) there is no real dip BELOW the nominal 300 ohms - which is quite high. What matters, when the amp output impedance is not sufficiently low, is the PERCENTAGE differentials between impedance at different frequencies. It's always between 1 and 2 for the HD600 - very easy.

So what's a sufficiently low output impedance here?

The percentage of power burned up from the amp's output impedance is:
Ra / (Rh + Ra)
Where Ra is amp output impedance and Rh is headphone impedance at a given frequency.

So let's say our amp is an OTL tube amp with rather high 60 ohms output impedance (any decent SS amp should be much lower):

For the one extreme on that impedance curve, the 300 ohms minimum:
power loss = 60/(300 + 60) = 16.67%
So the amp's power hitting the coil is down 10* log_10(1 - 0.1667) = -.79dB
So we lose less than one decibel due to even a very high output impedance of 60 ohms.

For the other extreme, at 560 ohms (~110 Hz):
power loss = 60/(60 + 560) = 9.68%
So here, the amp's power hitting the coil is down 10* log_10(1 - 0.0968) = -.44dB

So over the entire frequency spectrum, we have a max variation of only 0.35dB from even a relatively high output impedance of 60 ohms. The HD600 is a very, very easy load. The losses, as well as the differentials, rapidly vanishes to zero as the output impedance approaches 0. It will take an EXTREMELY high output impedance for the amp to cause severe anomalies in the frequency response with the HD600.

In my experience the HD600/650 certainly DO benefit greatly from high quality amplification, when the higher levels of fidelity are the goal. I don't think, however, that the specs indicate these headphones are in any manner difficult to drive adequately for less demanding applications.

It is not a myth, it is just perhaps an exaggeration mixed with intermittent snobbery.

Just about any headphone should be enjoyable out of an iPod. Of course the enjoyment can be furthered with amps and the like. Whether or not you want to "put up" with the sound of an undamped headphone is another story. People expectations and standards will vary.

Never let someone else make you feel like you shouldn't enjoy something you do!

Headphones are like speakers too. Yes a high end set of speakers can potentially sound good with a cheap Walmart amp and there are many people who will buy a nice set of speakers with a generic amp and be happy.

But if you get a higher current quality amp (this does not mean higher watts) you will get better tone. For me, if I have a good set of headphones or speakers that I will keep for a long time, I will get a quality amp to bring out the better tones and extention. But it's common as I said, for lots of people to get by on a marginal amp.

Once you become familar with a good headphone, you will see that an amp makes a difference.

Here's a comparison:

Just about every good guitarist uses a high quality amp for his/her electric guitar. A budget guitar amp can sound good actually but the player knows the guitar well enough to hear the difference of a higher quality amp for better sound. This is very common. Once you get to know the potential of your headphone, you may think like a guitarist baby.

You've been here long enough that you should know that most differences that are professed by people here are generally overblown, but they're still present and noticeable. No one is saying that you can't get enjoyment from your HD600 out of your iPod, but that to use the headphone to it's highest potential, all components upstream must be brought to at least the level of the headphone. A system can really only be as good as its weakest component, whether that be headphone, source, or amplifier.

As to your saying that one should buy the greatest headphones possible, then worrying about an amp and a source, I would disagree with that. When I regularly listened to my Koss Pro4AATs (my first real headphones), I was amazed by the difference I heard when I got my Gilmore Lite. Sonically, it was more impressive to me instantly than when I later received my HD650s and listened through the same setup (the difference, that is). What I mean to say, is, do not discount the benefit of an amp; it is an incredibly important component.