[Nocturnal310]

(Earphones with the exception to IEM's.)

I Wanted to buy a pair of Earphones for someone for use in Gym.

So i went to various shops.. all were 16 Ohm.. Sony & Audio technia

then
I checked out some Sennheisers MX320 ... they were the only 32 Ohm Earphones i saw.

Confused i decided to not buy & ask u all on head-fi.

Can u tell me for Earphones what difference will exist in 16 & 32 ohm in terms of quality.

And for average listening ... How better is 32 ohm?

Its a matter of only $5 but really wanna know.

 

[Duggeh]

The Ohm rating of a headphone has absolutely no direct relation to its sound quality.

You're going to wear them in the gym. If you can try them on before you buy, then buy the more comfortable ones. If you can't, then buy the cheaper ones. Simple practicality.

 

[Nocturnal310]

So the Ohm Rating of a headphone only indicates the Sound levels?

All i know is that high impedance headphones need an Amp..and below 32 Ohm u dont need an amp?

 

[Navyblue]

Quote:

Originally Posted by Nocturnal310 /img/forum/go_quote.gif and below 32 Ohm u dont need an amp?

Well, it depends on the particular phone and your player. But if you are talking about the affordable Sonys and ATs they benefit little from amping.

 

[Duggeh]

No, that's completely incorrect and is possibly the biggest piece of misinformation that gets circulated around these forums.

The sound level as I believe you mean the term, is dictated by the sensitivity rating, which is a measure of the sound volume output of a transducer per unit of electrical input power.

The ohm is a measure of electrical resistance, and to keep it simple, lower ohms in a headphone means that the driving amplifier tends to need more current output and higher ohm ratings mean that the amplifier needs to have greater voltage swing.

These two factors are NOT exclusive though. Low resistance headphones still need voltage swing from the amp and vice versa.

If you know your basic standard grade physics, then you can, by putting some imaginary figures through you head with regard to the formulae of interaction between voltage current and power, or resistance and power, or resistance or voltage or whatever you like, come up with patterns of numbers which illustrate this. Heres a rather convenient diagram of some of these interactions.

Don't worry if you don't understand this aspect of things though, its not necessary to understand in order to know.

These earbuds you are looking it will have high sensitivity ratings and will be designed to be run from the headphone output of portable audio devices. This isn't to say that they will not change in character with the use of a lager amplifier, but they will reach their maximum degree of transducer control with the use of a less capable amplifier than would be needed to gain maximum transducer control over a headphone which presents a more difficult load.


You're going to use the headphones in a gym, there will be background noise and you will be primarily focussed on your exercise, not an audiophile appreciation of the music or its reproduction. Buy the cheap buds and don't worry about them.

 

[Cool_Torpedo]

Quote:

Originally Posted by Nocturnal310 /img/forum/go_quote.gif So the Ohm Rating of a headphone only indicates the Sound levels? All i know is that high impedance headphones need an Amp..and below 32 Ohm u dont need an amp?

Facing things that way is plainly wrong. What tells you how loud will a pair of phones sound when feeding them with a certain amount of power is their sensitivity. This is normally given as dB/mW for headphones.
You should consider that most portable players deliver about 5mW of power, so any earphone with a sensitivity of 100 dB/mW or more will sound loud enough without an amp. And this is regardless of their impedance. In fact the lower the impedance, the more current intensity the phones will ask from the source, so a mix of low impedance (50 Ohm or less) and low sensitivity (less than 97dB/mW) is the kind of earphone that would stress the most any source or amp.

What can seem confusing is that high impedance phones are also low sensitivity ones, then they need more power to sound loud, but the impedance itself is not the cause they need more power, just their sensitivity.

Rgrds

 

[Nocturnal310]

oh.. So if High impedance needs an Amp..

then whats the advantage of having 150 Ohm Headphones for listening music? Just additional cost for amps.?/

 

[Duggeh]

You're totally not getting the point.

Its not that high or low impedance means a headphones needs an amp. There is no inherent advantage to high or low impedance in moving-coil drivers. There's no inherent disadvantage either, its simply a characteristic which is produced as a result of how the transducer has been engineered.

Impedance is only one factor of several which dictate the degree to which a transducer requires more powerful amplification. As a rule or even a guide in itself it is worthless. The whole "high impedance headphones need amps and low impedance ones dont" myth has come about as a retrotech from the equally overly simplistic "Sennheisers need amps and Grados don't need them as much" myth.

 

[Cool_Torpedo]

Quote:

Originally Posted by Duggeh /img/forum/go_quote.gif You're totally not getting the point. Its not that high or low impedance means a headphones needs an amp. There is no inherent advantage to high or low impedance in moving-coil drivers. There's no inherent disadvantage either, its simply a characteristic which is produced as a result of how the transducer has been engineered. Impedance is only one factor of several which dictate the degree to which a transducer requires more powerful amplification. As a rule or even a guide in itself it is worthless. The whole "high impedance headphones need amps and low impedance ones dont" myth has come about as a retrotech from the equally overly simplistic "Sennheisers need amps and Grados don't need them as much" myth.

Duggeh, mate, you have all my sympathy for your patience. I had given up yesterday

Rgrds

 

[Navyblue]

I think we need a bit of tact, we all start somewhere.

 

[Cool_Torpedo]

I don't know what you need, but Duggeh and I took some time to explain why impedance isn't the only parameter that matters to know if a phone will sound loud and decent from a player's or DAP's output. OP's reply shows clearly that he didn't care to read what we wrote or that he's too firm in his beliefs to accept the facts. In either case I'm not very prone to insist, frankly.

Rgrds

 

[MechE]

Hi,
I registered after I read this post. It can matter. I have a SanDisk Sansa m250,which is powered by a single cell AAA, which runs around 1.2v (I use NiMH, this thing don't last worth a thing on alkaline) and the voltage available to the amplifier is quite limited.

So, I broke the original set of earphones that came with it. The original set was 4 or 8 ohms, really low for earphones.

The replacement generic I got was 32 ohms. The amplifier didn't have enough voltage to drive them loud enough even at maximum volume to overcome gym noise.

The problem was resolved by replacing them with a set of 16 ohm earphones. Although not as loud as the original sets at any given volume setting, it was loud enough to meet my needs.

At the same voltage, the power delivered is inversely proportional to impedance. Double the resistance, you halve the delivered power.

If you reduce the resistance, the power keeps increasing until the amplifier is no longer able to supply the current.

 

[espire]

MechE, what Duggeh and Cool_Torpedo are explaining is that the impedance of the headphone does not dictate how sensitive they are. There is often a correlation between the two, but you should not use impedance as a guide to how sensitive a headphone is.

On the side, does anybody have a good in-depth link explaining impedance and the like without using formulas?

 

[iamresumes]

to me ohm dosen't mean anything, its depend on ur gears!!

 

[MechE]

Quote:

Originally Posted by espire /img/forum/go_quote.gif MechE, what Duggeh and Cool_Torpedo are explaining is that the impedance of the headphone does not dictate how sensitive they are. There is often a correlation between the two, but you should not use impedance as a guide to how sensitive a headphone is. On the side, does anybody have a good in-depth link explaining impedance and the like without using formulas?

Hello espire,
I was not talking about sensitivity at all. Sensitivity is a relationship between the SPL (dB) and the electrical input in mW

I'm not going to get into the affect of impedance on quality, but it has a tremendous affect on the deliverable power.

Let's compare a semi and a Ferrari. They may both have about 500hp, but a semi does it at 2500RPM and a Ferarri at 10,000RPM.

If you mate a semi engine with a Ferrari drive train, the engine still maxes out at 2,500RPM with a boat load of torque to spare, but you won't be delivering 500hp

Put it the other way around, the Ferrari engine won't have enough torque to be able to spin up to 10,000RPM with the amount of torque placed by a semi drive-train.

Going back to electrical talk, with two headphones having exactly the same sensitivity given the same voltage electrical signal, but one is 16 ohm and the other is 32 ohm and I=E/R and P=EI, so the power is inversely proprotional to impedance given the same voltage...

Therefore. if you use an amplifier who's output voltage is limited (battery powered in particular, especially single 1.5v type) with high impedance headphone, the maximum power becomes rather limited.