Headphones

Started by Bonehelm, June 10, 2007, 02:50:21 PM

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DavidW

Quote from: George on July 31, 2009, 09:05:03 AM
Thanks for the photo and the explanation. If I understand this properly, the higher impedance at that frequency (without ample power) would result in a less bassy sound, right? Since there is more resistance at those frequencies, less information from those frequencies will be heard. Yet, I am having the opposite effect.


Well you have to remember that it's all being played at the same time, and then it takes most of the juice just to thump that bass, and the mids end up sounding weak.  If you play something that's tightly mids it won't sound as recessed, and I've noticed that. 

jlaurson

Quote from: George on July 31, 2009, 09:16:07 AM
If I could be sure that a $200 HP amp would get my HP sounding balanced, I would seriously consider it. I agree that the treble solution is a band aid that throws the tonal balance off in other ways, but I actually don't listen to my HP that often, as I prefer to listen on speakers. My girlfriend forces me into it when she's home.  :-\   

Do you have anything resembling a HiFi store nearby? Or anywhere where you are planning to travel for business or leisure? Take you headphones, favorite CDs (that you don't like with headphones), and go there... listen to that CD with the phones plugged into any (lower-end, to make a point) CD player directly... and then with that CD player hooked up to a decent HeadAmp through the latter. You'll hear if it makes the right difference for you. (It will certainly make a big difference... the question is whether it can undo certain reactions/dislikes of yours to what you have right now and what your expectations are.) Once you know that, you can shop around for an Amp or new headphones... which should then be chosen with low impedance in mind (if you don't get an amp, after all.) Unfortunately Grados, among the best headphones available with low impedance, are not really suitable for making the girlfriend happy, because they don't isolate the sound well at all. (In their defense: they're not meant to.)

George

Quote from: DavidW on July 31, 2009, 09:21:36 AM
Well you have to remember that it's all being played at the same time, and then it takes most of the juice just to thump that bass, and the mids end up sounding weak.  If you play something that's tightly mids it won't sound as recessed, and I've noticed that. 

Ah, I see. That makes sense, thanks!

George

Quote from: jlaurson on July 31, 2009, 09:29:36 AM
Do you have anything resembling a HiFi store nearby? Or anywhere where you are planning to travel for business or leisure? Take you headphones, favorite CDs (that you don't like with headphones), and go there... listen to that CD with the phones plugged into any (lower-end, to make a point) CD player directly... and then with that CD player hooked up to a decent HeadAmp through the latter. You'll hear if it makes the right difference for you. (It will certainly make a big difference... the question is whether it can undo certain reactions/dislikes of yours to what you have right now and what your expectations are.) Once you know that, you can shop around for an Amp or new headphones... which should then be chosen with low impedance in mind (if you don't get an amp, after all.) Unfortunately Grados, among the best headphones available with low impedance, are not really suitable for making the girlfriend happy, because they don't isolate the sound well at all. (In their defense: they're not meant to.)

All good stuff, thanks. Certainly the 580s don't isolate the sound either.

I just haven't found a shop yet in NYC that carries Headphone amps. I haven't looked very hard, but I would prefer to audition a unit that I would eventually buy. I'm going to more active search, unfortunately in New York City we have only either rinky-dink stereo places like Best Buy or Top of the Line places with equipment that I will never be able to afford.  

Scarpia

#204
Quote from: George on July 31, 2009, 09:05:03 AM
Thanks for the photo and the explanation. If I understand this properly, the higher impedance at that frequency (without ample power) would result in a less bassy sound, right? Since there is more resistance at those frequencies, less information from those frequencies will be heard. Yet, I am having the opposite effect.

High impedance means the headphones will draw less current.  When your amplifier produces a certain voltage at 100 Hz, the 600 Ohm impedance means the headphone will draw less current than if it received the same voltage at 1000 Hz, where the impedance is only 300 Ohms.  Since the amplifier produces a set voltage, and the sound from a dynamic speaker is proportional to current, the high impedance at 100 Hz tends to reduce the response at 100 Hz.   However, Sennheiser took this into account when they designed the headphone.

But this assumes that your amplifier is a perfect voltage source.  Suppose your cheap portable player is a poor voltage source.  It has its own impedance.  Lets say your lousy cheap amplifier has an output impedance that is a constant 300 Ohms.  Then at 100 Hz, the total impedance is 300 Ohms + 600 Ohms = 900 Ohms.  The impedance went up from 600 to 900, that's a 50% increase in impedance, and a 50% drop in current.  But at 1000 Hz the total impedance is 300 Ohms + 300 Ohms = 600 Ohms.  The impedance went up from 300 to 600, it doubled, and the current is cut in half.  The 1000 Hz signal would therefore be attenuated more than the 100 Hz signal when you use the cheap amplifier, and the treble would become weaker.

I certainly believe that an iPod or computer would be a poor driver for headphones.  But I don't believe that a headphone amp is necessary if you have a good audio amplifier.  I use old-school NAD preamps (model 1155) and I find that the headphone output on that amp sounds just as good as my headphone amp.

Anyway, I also had a pair of HD580, they ended up in the trash can.  Those little jacks that connect the cable to the phones kept getting loose, the replaceable earpads didn't snap in properly anymore and were buzzing, then the response of the left side suddenly dropped off.  Finally lost my patience with them.  Could have tried to sell them on ebay but I didn't want to risk bad feedback.  Now I have AKG-701.


George


Holden

Quote from: George on July 31, 2009, 09:16:07 AM


If I could be sure that a $200 HP amp would get my HP sounding balanced, I would seriously consider it. I agree that the treble solution is a band aid that throws the tonal balance off in other ways, but I actually don't listen to my HP that often, as I prefer to listen on speakers. My girlfriend forces me into it when she's home.  :-\   



I bought the above (ridiculously cheap) to drive my Senn 280s. I was amazed at the difference they made, especially the bass. They also made the Senns sound a lot brighter. For $30 you can't go wrong and it will give you an idea of what a HP amp can do.
Cheers

Holden

drogulus

Quote from: DavidW on July 31, 2009, 07:59:06 AM
The impedance is a function of frequency and it peaks at 100 Hz with a whopping 550+ ohms!  Poorly amplified, the 580 will effectively be bloated and not neutral.  Here is a graph of the 600's impedance (same driver as the 580) which illustrates the point.



So the headphone will interact with a poor amp in a frequency dependent way. 8)

     How high would the source impedance have to be? The iPods are around 5 Ohms. Most of the objective stuff I've read says that iPods are good for most headphones. The problem with high impedance 'phones seems to be they will draw more current than the player can cleanly provide. In that sense an mp3 player might be an inadequate amplifier. Most people aren't going to use 300 Ohm 'phones with their players, though. For typical phones there shouldn't be an impedance problem. There might be a "these 'phones suck!" problem which is not the players fault.  :D

     Here are 2 threads that touch on the issue of amps, player SQ, and impedance:

     Players and amps (general SQ) at AVS Forum:

     How good is the ipod's DAC?

     Amps and impedance at Hydrogenaudio:

     What does a secondary headphone amp do exactly?
     
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Scarpia

Quote from: drogulus on July 31, 2009, 02:15:36 PM
The problem with high impedance 'phones seems to be they will draw more current than the player can cleanly provide.

You've got it backwards.  V = I R  (V-voltage, I=current, R-resistance).   Impedance (Z) is a generalized version of resistance, which describe a situation where voltage and current have a relative phase shift.  Neglecting that for the moment we can replace R with Z, then V = I Z or

I = V/Z.

Current is voltage divided by impedance.  The issue is that the typical audio amplifier is a voltage source, and if the impedance is high it takes a higher voltage to generate the same current.  The volume control on your amplifier controls voltage, and you have to turn it up higher to get the same volume with a high impedance load.  

So it's not that high impedance headphones draw more current, they draw less current and you have to turn the volume up higher to get them to play at the same volume as a low impedance headphone.  However, high impedance headphones are less sensitive to a poor quality, high output impedance amplifier, since to get good performance the impedance of the load should be higher than the impedance of the source.

drogulus


   Ah, yes. You're right, they will draw less current. So efficiency would be the problem.

   Still, why do you say the iPod is a high impedance source? Is 5 Ohms high for headphones? Since the load is higher than the source why would the impedance be a problem? The links I provided indicate that it isn't. Wouldn't 'phones with an unusually low impedance (below 16 Ohms, say) be more of a problem?
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DavidW

Quote from: drogulus on July 31, 2009, 02:15:36 PM
    How high would the source impedance have to be? The iPods are around 5 Ohms. Most of the objective stuff I've read says that iPods are good for most headphones.

The problem is more a matter of voltage (or power really) supplied by the dap's amp and the power sensitivity of the headphones.  High impedance cans use less current anyway (Ohms Law).  Most mp3 players do not offer enough voltage to drive every headphone well, they are designed to usually drive ear buds which have a significantly higher power sensitivity than your favorite Sennheiser 600 or akg k701 monster.

It doesn't take that much power-- order of magnitude is .01 W, but considering the impedance involved you need a minimum of a few volts for headphones like the Sennheiser 580.  A portable head phone amp will get you there but they are usually less than 10 mW (our order of magnitude threshold) and just not close enough.  I don't know about the ipod specifically.

Scarpia

#211
Quote from: drogulus on July 31, 2009, 02:39:50 PM
   Ah, yes. You're right, they will draw less current. So efficiency would be the problem.

   Still, why do you say the iPod is a high impedance source? Is 5 Ohms high for headphones? Since the load is higher than the source why would the impedance be a problem? The links I provided indicate that it isn't. Wouldn't 'phones with an unusually low impedance (below 16 Ohms, say) be more of a problem?

I was referring to a hypothetical poor quality amplifier with high output impedance.  I don't have any specific knowledge of an ipod.  It can be that if the ipod doesn't have sufficient power supply or output transistors the output saturates or suffers from slew rate limitations when the volume is too high.

violinconcerto

Hello!

Can anybody recommend some in-ear-headphones? I am looking for something I can wear when I am travelling, which stops the noise around me and sound good for classical music. Price could be up to 100US$, but not more expensive.
Any suggestions?

Thanks and best,
Tobias

jlaurson

Quote from: violinconcerto on August 06, 2009, 03:01:43 AM
Hello!

Can anybody recommend some in-ear-headphones? I am looking for something I can wear when I am travelling, which stops the noise around me and sound good for classical music. Price could be up to 100US$, but not more expensive.
Any suggestions?

Thanks and best,
Tobias

I'm very, very happy with my Etymotics ER6i (and their customer service), but I've not had the opportunity to compare them to the direct competition such as Shure and as of late Sony and Sennheiser's in-ear models. Block noise almost completely (way too dangerous to wear in traffic, as I found out the hard way); very crisp, clear, and clean sound.

If customs lets it slip through, they'd be MUCH less expensive ordered from the US (link above) than from Germany. (This link.)




DavidW

I received my Sennheiser 650s the day before yesterday.  That evening I tried it with the recording of Kosler, Tafelmusik on Mozart's Horn Concertos and I WAS BLOWN AWAY!  It sounded like a live concert, I was just floored.  I've listened to Frescobaldi chamber works, and Liszt piano concertos and the piano sonata as well on those headphones.  I don't think it has the bass hump that everyone says it does (on head-fi that is).  It sounded neutral, just with an extended detailed bass.  It's like the akg k501's mids but for everything: bass, mids, treble.  I really appreciated the fullness of the sound, the good separation of instruments, and the slightly rolled off treble to communicate the full information without sounding harsh and overly forward.

It makes it sound like a live concert experience, and that is just terrific!  I'm happy. :)

DavidRoss

Quote from: violinconcerto on August 06, 2009, 03:01:43 AM
Hello!

Can anybody recommend some in-ear-headphones? I am looking for something I can wear when I am travelling, which stops the noise around me and sound good for classical music. Price could be up to 100US$, but not more expensive.
Any suggestions?

Thanks and best,
Tobias

Like Jens, I use the Ety 6i and am very happy with them. 
"Maybe the problem most of you have ... is that you're not listening to Barbirolli." ~Sarge

"The problem with socialism is that sooner or later you run out of other people's money." ~Margaret Thatcher

violinconcerto

Thanks for your comments!
The Etymotics look good, but are they comfortable to wear? Looks like you have to "press" the ear plug into the ear canal.
I keep an eye on the Ety and the Sennheiser, but first I give it a try on ebay and there are a few nice looking Shure headphones right now. Maybe they won't rise in the price and then I go for them. Otherwise I give the Ety a try, I think.

Thanks again for your thoughts on that!

Best,
Tobias

jlaurson

Quote from: violinconcerto on August 07, 2009, 12:35:57 AM
Thanks for your comments!
The Etymotics look good, but are they comfortable to wear? Looks like you have to "press" the ear plug into the ear canal.
Tobias

The comfort probably differs from ear to ear. They have different flanges they come with. I use the "Christmas Tree" (triple flange) rubber tips and once I got used to them (almost immediately), I've quite liked them. Takes a few second to get them back out of the ear, but easy to insert. (Can't stand anything made of foam.)

One side note: Etymotics pretty much only have high-quality ear-phones. I don't think they even produce anything "below" ER6 -- whereas Sennheiser and Shure, while companies that make quality product by all means, service all but the super-budget market niches. Therefore a Shure may well be offered for 20,- -- but it isn't necessarily the Shure product that would most reasonably be compared to the ER6i.

Scarpia

Three month old set of Sennheiser HD600 headphones have just gone back to Sennheiser for warranty repair or replacement.  In retrospect I noticed the problem immediately but it took some time to convince myself that the headphones I had paid a lot of money for were really defective.  The problem is a buzzing in the left ear phone whenever there is significant low frequency sound.  If you listen for it you can hear it in a variety of passages, it only is obvious when the low frequency sound is fairly exposed (such as cello solo passage in a string quartet).  I will update this entry with information about how satisfactory Sennheiser repair service is.

In any case, it is very annoying to spend a lot of money and end up with nothing but the bill.  Since the problem isn't super obvious, my main concern is that I will get the headphones back with a terse note that there is nothing wrong with them. 

This experience tends to confirm my dissatisfaction with Sennheiser's high end products, they are very fragile.  I previously had a pair of HD580's which were fine at first but which developed a lot of annoying problems.  The cable is removable and the little connectors tend to get loose and cause static.  The ear pads snap in and after a few changes they don't snap in as securely and cause buzzing.  Finally one side gave out and I tossed them in the trash.


DavidW

I had a buzzing problem with my 580s and I sent them in for repair (very slow turnaround on that), and it turned out to be simply from a piece of hair that fell on the driver.  But at least they also cleaned them up and made them sound good as new again, they were years old at the time though and not just three months.