A small clarification
post-174355
Thread Starter
Post #1 of 14

Jeff Guidry

Headphoneus Supremus
Joined
Apr 6, 2002
Messages
2,614
Reaction score
12
Joined
Apr 6, 2002
Posts
2,614
Likes
12
I am posting these observations to clarify what I think is an unfortunate lapse in correct usage of terminology. It is fairly small, and doubtless some of you with think it is petty of me to mention it. No matter. I hope newbies will find this post and gain enlightenment...

Often, we say of low impedance headphones that 'they don't need an amplifier' or of high impedance headphones 'you really need an amplifier with these'. Well, in truth, ALL headphones need amplification above and beyond the voltage and current provided by the line level signal to reach a satisfying volume. Virtually all portable devices and some home devices include an amplifier that you plug your headphones into that is designed to add gain to the line level signal.

Often, it is the amount of gain that this on-board amplifier provides that is called into question with higher impedance headphones. With most modern portables, their rated output is very low, and does not provide sufficient current and voltage to drive high impedance headphones to satisfying volume levels. Also, since high impedance headphones have much higher current demands than low impedance headphones, even if you get enough SPL from them from the on-board amplifier, the sound will often not be satisfactory, because you are driving the on-board amplifier to the limits that it was designed to operate at, perhaps even beyond.

Plus, on-board amplifiers on most portable equipment and sound cards, etc. are not designed to reproduce high-fidelity audio, and lack in overall sound quality.

Adding an out-board headphone amplifier does several things to improve the sound. First, it takes the power burden away from the small and underpowered on-board amplifier and devotes it solely to operating the cdp, md, etc. allowing it to better do it's job. Second, the out-board amplifier will in virtually all cases have much better circuitry and fewer compromises in the design, along with a much more plentiful power supply, so the out-board amplifier can do an overall better job, because that is the only job it was designed to do.

The reason I want to make sure newbies recoginze the distinction is so they are less confused when we say "the V6's don't need an amplifier". They do. Because they are a low impedance headphone, it is not necessary to add an outboard amplifier to get satisfying levels out of them. But, because of the reasons listed above, you can make them sound better, sometimes MUCH better, if you get an outboard amplifier for them. Likewise, when we say "the HD600 need an amplifier" you are simply stating the obvious. Of course they need an amplifier, all headphones do. But again, because of the reasons stated above, if you want to get the best sound out of them, you will want to get an out-board headphone amplifier.

I hope I have enlightened the newbies, and I hope I have not bored the veterans too much.
 
     Share This Post       
post-174368
Post #2 of 14

jpelg

Needs a regular fix of 'Fi
'06 Nat Meet Co-Coordinator
Joined
Jan 19, 2002
Messages
8,675
Reaction score
26
Location
The Elm City
Joined
Jan 19, 2002
Location
The Elm City
Posts
8,675
Likes
26
Quote:

even if you get enough SPL from them from the on-board amplifier, the sound will often not be satisfactory.


SPL?

It is generally not a good idea to attempt clarification of terms or concepts by introducing other language and acronyms that have not been previously defined themselves. When writing technical documentation you really need a definition of terms. Never, never assume things unless you make it clear at the beginning what it is that you will be "assuming".
 
     Share This Post       
post-174370
Post #3 of 14

DanG

Headphoneus Supremus
Moderator
Joined
Jun 20, 2001
Messages
4,796
Reaction score
10
Joined
Jun 20, 2001
Posts
4,796
Likes
10
For the most part I think you're right, Jeff. However when you put forth the example of the V6 I began thinking about the differences I heard with and without a headphone amp with my V6 (before it was lost). While all the high-end headphones I've owned benefited enormously from a good headphone amp -- namely the Ety 4S, the Grados I've had, and the Senn600 -- the V6 barely benefited. Why? Well for one thing there is the power issue as you mentioned. All that changes is that there's a better circuit, better power supply, and better parts but the headphone remains the same (many have I loved, many times been bitten
). There was a difference, but it was so much less than with the Senn600 or Ety4S (the other two headphones I had then) that it made me realize that it's barely worth getting an amp for low-end headphones -- the same goes for headphones like the Sony MDR-E888, Koss KSC-35, etc.

Well, here I go debating something that wasn't meant to be debated I suppose. But maybe it'll make the thread last longer.
 
     Share This Post       
post-174408
Post #4 of 14

fiddler

Headphoneus Supremus
Joined
Jun 24, 2001
Messages
1,930
Reaction score
30
Joined
Jun 24, 2001
Posts
1,930
Likes
30
Quote:

Also, since high impedance headphones have much higher current demands than low impedance headphones.


I thought that low-impedance phones require lots of current (hence the A47 amp was made to supply lots of current specifically for Grados) while high impedance phones don't require much current but need lots of voltage swing.
 
     Share This Post       
post-174419
Post #5 of 14

andrzejpw

May one day invent Bose-cancelling headphones.
Joined
Jun 25, 2001
Messages
6,636
Reaction score
10
Joined
Jun 25, 2001
Posts
6,636
Likes
10
one of the most confusing things, I think, is when we say that HD600s need an amp. A newbie may say "why do I need an amp? I'm listening to them out of my cd player, and they can get VERY loud! I don't need them louder!"

An amp's job is to add quality, with quantity taking the back seat.
 
     Share This Post       
post-174479
Post #6 of 14

lini

Thought the last line in Citizen Kane was nosebud.
Joined
Jun 22, 2001
Messages
6,117
Reaction score
21
Joined
Jun 22, 2001
Posts
6,117
Likes
21
fiddler: At roughly the same efficiency, yes. But, of course, for very efficient low impedance headphones the current isn't that high at all (or the voltage for very efficient high impedance headphones)...

Anyway, on an internet forum a certain level of precision will always have to be traded in for speed. I don't think that threads at heair-splitting level would be fun to read, anymore...

Greetings from Munich!

Manfred / lini
 
     Share This Post       
post-174577
Post #7 of 14

Budgie

Never looks a gift amp in the jackhole.
Joined
Jun 22, 2001
Messages
2,154
Reaction score
18
Joined
Jun 22, 2001
Posts
2,154
Likes
18
It is even more complicated then that.
If we presume that the phones are seeing identical voltage, the lower impedance phone will draw more current (if the source can provide it), effectively getting more power from the source. At that identical voltage, the higher impedance phones will draw less current and will effectivly getting less power.

If we presume that both pairs of phones need the same current to provide the same volume level, the low impedance phones will do so at a lower voltage, the high impedance phones will need higher voltage to draw that same current.

The above models are all simple ohms law relationships, that define the power delivered to the load (phones). The other factor that is as important, is the efficency of the phones. The phones ability to turn the power into sound pressure is never 100% and will vary widely from model to model and from manufacturer to manufacturer. The mechanical and acoustic design of the driver decides its efficiency. Some phones will be louder then others, even with the same power driving them. Interestingly, the higher the efficency, the higher the power handling. The reason being that the power not being turned into sound pressure is wasted as heating of the elements, which can lead to failure of the driver.

Even after the sound is produced, some volume is lost due to the distance between the driver element and the ear. In this instance the design of the cup and earpad come into play.
 
     Share This Post       
post-174697
Post #8 of 14

Jeff Guidry

Headphoneus Supremus
Joined
Apr 6, 2002
Messages
2,614
Reaction score
12
Joined
Apr 6, 2002
Posts
2,614
Likes
12
Quote:

Originally posted by jpelg
SPL?

It is generally not a good idea to attempt clarification of terms or concepts by introducing other language and acronyms that have not been previously defined themselves. When writing technical documentation you really need a definition of terms. Never, never assume things unless you make it clear at the beginning what it is that you will be "assuming".


Well, I did not attempt to define basic audio terms. I am not a technician, and I would not presume to write a technical document. If a newbie is unfamiliar with the term SPL (sound pressure level), then they need a better background in terminology before they will begin to understand ANYTHING discussed on these boards.

Lini, as the title of the thread suggests, this is only a small clarifcation, and I suppose it is in fact on the hair-splitting level for an experienced person such as yourself. But a newbie hungry for information may find this clarification an important resource. Maybe.

DanG, I disagree that the V6's do not benefit from better amplification. I own the V6's and the difference between their sound from the headphone out of my Panasonic 570 and
from adding the Cmoy to the line out of the same Pana 570, is noticeable and desirable. To me.

Thanks for all your input guys. It is just this sort of discussion that I had hoped to stimulate. We must remember that their are many, many lurkers who don't post but who are looking for solid information to expand their knowledge. I hope that we can provide as much of that in as clear a manner as possible.
 
     Share This Post       
post-174756
Post #9 of 14

jpelg

Needs a regular fix of 'Fi
'06 Nat Meet Co-Coordinator
Joined
Jan 19, 2002
Messages
8,675
Reaction score
26
Location
The Elm City
Joined
Jan 19, 2002
Location
The Elm City
Posts
8,675
Likes
26
Quote:

Originally posted by Jeff Guidry
I am posting these observations to clarify what I think is an unfortunate lapse in correct usage of terminology. It is fairly small, and doubtless some of you with think it is petty of me to mention it. No matter. I hope newbies will find this post and gain enlightenment...


Quote:

But a newbie hungry for information may find this clarification an important resource.


Quote:

their are many, many lurkers who don't post but who are looking for solid information to expand their knowledge. I hope that we can provide as much of that in as clear a manner as possible


And yet... Quote:

Well, I did not attempt to define basic audio terms. I am not a technician, and I would not presume to write a technical document. If a newbie is unfamiliar with the term SPL (sound pressure level), then they need a better background in terminology before they will begin to understand ANYTHING discussed on these boards


Uh, ok...
 
     Share This Post       
post-174764
Post #10 of 14

Jeff Guidry

Headphoneus Supremus
Joined
Apr 6, 2002
Messages
2,614
Reaction score
12
Joined
Apr 6, 2002
Posts
2,614
Likes
12
I'm sorry jpelg if I have upset you. All I am trying to do is to provide a resource for newbies to understand a specific statement that is often bandied about here on the forum. I don't think that my statements are contradictary, but you seem to be rather adamant they are. So, I'm sorry. Since I seem to be unable to express myself clearly, I will cease contributing to this thread, since it appears that I am obscuring the issue rather than clarifying it.
 
     Share This Post       
post-174771
Post #11 of 14

LarryS

100+ Head-Fier
Joined
Jan 24, 2002
Messages
190
Reaction score
0
Joined
Jan 24, 2002
Posts
190
Likes
0
(never mind)
(cannot delete comment)
 
     Share This Post       
post-174846
Post #12 of 14

lini

Thought the last line in Citizen Kane was nosebud.
Joined
Jun 22, 2001
Messages
6,117
Reaction score
21
Joined
Jun 22, 2001
Posts
6,117
Likes
21
Jeff: Ok, I see the purpose - but don't you think the thread will scroll into oblivion all too soon, anyway? We'd probably need a sticky "FAQ for Newbies"...

Greetings from Munich!

Manfred / lini
 
     Share This Post       
post-174855
Post #13 of 14

Duncan

Headphoneus Supremus
Moderator
Joined
Jun 26, 2001
Messages
13,162
Reaction score
1,262
Joined
Jun 26, 2001
Posts
13,162
Likes
1,262
Quote:

Originally posted by Jeff Guidry
DanG, I disagree that the V6's do not benefit from better amplification. I own the V6's and the difference between their sound from the headphone out of my Panasonic 570 and
from adding the Cmoy to the line out of the same Pana 570, is noticeable and desirable. To me.


Not to be awkward, (and sticking to the PCDPs) but with my Sony E905 the V6 sound better through the headphone out than they do with the line out with either my CHA47, META42 or even the X-Can V2... Granted, to all intents and purposes I have an exceptional top of the line PCDP, but to tar all equipment with the same brush would then potentially confuse newbies all the more...

The key differences, the headphone out sounds punchier, airier (wider) and more alive than the line out, which in direct comparison sounds a shade dry and flat

BUT... different story with my Sony CD1700s... where to me an amp does reap benefits... even though on paper at least the CD1700s should be even more capable of being driven cleanly through my Sony player...

It to me at least goes a LOT deeper than two or three variables, granted if you attempted to list each and every little nuance of a difference you'd be here for forever and a day arguing about it... but to say there are clear cut differences would be as unfair to a newbie as to say nothing at all?!

The one thing i'm not quite sure on myself which you techno-guys could explain, is where the 'energy' of a pair of 'phones comes from... out of all of my headphones the lowly V6 has by far and away the most energy and pace... with all others sounding slow, and sombre in direct comparison (although longer listening does reveal that the more expensive 'phones do have their own benefits)... its not impedance, its not SPL, its not power rating... its not even (on paper at least) the driver frequency response... any clues?
 
     Share This Post       
post-174922
Post #14 of 14

grinch

Cognac....icky.Scotch....icky.Vodka....
Joined
Jan 1, 2002
Messages
3,077
Reaction score
11
Joined
Jan 1, 2002
Posts
3,077
Likes
11
Quote:

Originally posted by andrzejpw
one of the most confusing things, I think, is when we say that HD600s need an amp. A newbie may say "why do I need an amp? I'm listening to them out of my cd player, and they can get VERY loud! I don't need them louder!"

An amp's job is to add quality, with quantity taking the back seat.


i hate this disillusion so much. everytime i tell anybody about my headphone amplifiers, they say "i never understood why people want to listen to their music so loudly.." AHHHHHH #@$&*(&#@*()$&#*(@ i am not a fan of music that is too loud!

i think it comes from car audio systems. everybody buys amps for their car systems so that they can be heard from two blocks away. what people don't know is, that proper amplification provides a cleaner sound. oh well, someday i'll convince everybody of this..
 
     Share This Post       

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top