*Comparison and Review* Magni/Modi vs O2/ODAC

[dclaz]

Interesting. Are the HE-400's considered hard to drive? 

 

[xnor]

  Interesting. Are the HE-400's considered hard to drive? 

Absolutely not. The HE-400 is more sensitive and efficient than the HE-500, which is not hard to drive itself.
 
With the ODAC/O2 you might even be fine with no (0 dB) gain, and less gain is better.

 

[TMRaven]

There might be a difference in scalability between the two, but in general most modern headphones are not hard to drive at all.  It's especially true with the relative sensitive planars like LCD2 and HE-400, because planars don't really change their sound depending on the output impedance of the amp.

 

[dclaz]

  There might be a difference in scalability between the two, but in general most modern headphones are not hard to drive at all.  It's especially true with the relative sensitive planars like LCD2 and HE-400, because planars don't really change their sound depending on the output impedance of the amp.

 
Pardon my ignorance, but I thought things like the LCD2 were very hard to drive? And when you say their sound doesn't change, do you mean it's just quieter at all frequencies as opposed to softer in certain areas?

 

[xnor]

The LCD2 is not hard to drive. It's close to a resistive load, so easier to drive than any dynamic headphone in that respect, and fairly sensitive/efficient. Easier to drive than a K701 for example. Needs less current than the Custom One Pro, less voltage than a DT770 Pro or HD600.
 
In my table it is listed with negative gain, so your amp probably doesn't need any gain with the ODAC. Yeah, it's that easy to drive and yeah, most headphones are.
 
edit: http://www.youtube.com/watch?v=3I2lyIQDC24 shows the magnets which are pretty strong.
 
 
The change due to output impedance doesn't really matter here because afaik both O2 and Magni have close to 0 ohm outputs.
 
edit: But if you're interested: something like a receiver's headphone jack has a high output impedance. This causes, for example, a bass boost and loose bass with dynamic headphones. Planar magnetics are pretty much purely resistive loads so they don't really care about the output impedance.
So, if you switch from the Magni or O2 to a receiver with a HD555 you will hear a huge different in the bass, with a HE- or LCD or other planar magnetic headphone you won't.

 

[TMRaven]

   
Pardon my ignorance, but I thought things like the LCD2 were very hard to drive? And when you say their sound doesn't change, do you mean it's just quieter at all frequencies as opposed to softer in certain areas?

 
 
There might be a scaling difference, but as far as pure power, there's really not much difference between the LCD2 and HE-400 for instance.  Take the HE-400 on the Magni, and you'll get a satisfying volume at 9 o'clock.  Put the LCD2 on the Magni, and you'll get that same satisfying volume at 9:30ish.
 
On the topic of scalability, LCD2 might have the better technicalities in lower distortion, resonance and a more even frequency response-- or whatever else, that the small subtle improvements with better gear can be more apparent than the HE-400, which sorta has its own coloration and qualities depending regardless of the upstream components.  It seems as though people confuse that with the need for raw power.

 

[SunshineReggae]

   
Pardon my ignorance, but I thought things like the LCD2 were very hard to drive? And when you say their sound doesn't change, do you mean it's just quieter at all frequencies as opposed to softer in certain areas?

 
It probably stems from the flawed logic that if a headphone is expensive, that it would follow that it requires an expensive amp to 'drive properly'. (Meanwhile, there is no subjective consensus about what it means when an amp is 'driving a headphone 'properly'. It usually translates to terminology such as 'tight control over the bass', 'opening up' the headphone, etc.).

 

[dclaz]

  The LCD2 is not hard to drive. It's close to a resistive load, so easier to drive than any dynamic headphone in that respect, and fairly sensitive/efficient. Easier to drive than a K701 for example. Needs less current than the Custom One Pro, less voltage than a DT770 Pro or HD600.
 
In my table it is listed with negative gain, so your amp probably doesn't need any gain with the ODAC. Yeah, it's that easy to drive and yeah, most headphones are.
 
edit: http://www.youtube.com/watch?v=3I2lyIQDC24 shows the magnets which are pretty strong.
 
 
The change due to output impedance doesn't really matter here because afaik both O2 and Magni have close to 0 ohm outputs.
 
edit: But if you're interested: something like a receiver's headphone jack has a high output impedance. This causes, for example, a bass boost and loose bass with dynamic headphones. Planar magnetics are pretty much purely resistive loads so they don't really care about the output impedance.
So, if you switch from the Magni or O2 to a receiver with a HD555 you will hear a huge different in the bass, with a HE- or LCD or other planar magnetic headphone you won't.

 
 

   
It probably stems from the flawed logic that if a headphone is expensive, that it would follow that it requires an expensive amp to 'drive properly'. (Meanwhile, there is no subjective consensus about what it means when an amp is 'driving a headphone 'properly'. It usually translates to terminology such as 'tight control over the bass', 'opening up' the headphone, etc.).

 
 
I see, it just feels like I keep hearing comments about how hard they are to drive, and they they sound crap if underpowered?
 
So the statement here is incorrect? 
http://headphones.com.au/psingle?productID=511

Being one of the more difficult headphones to drive, a good amp is an absolute must.
 

In this case, I can understand they might be trying to flog an amp....
 
And most outputs can put out over 1w? as per http://support.audeze.com/entries/20866002-Selecting-an-amp- ?

 

[xnor]

Well sensitivity ranges from 102 (for the rev2, but we only have 1 data point) to roughly 109 dB SPL @ 1V. The ODAC outputs 2 V, so you can add 6 dB to that plus the gain of the amp.
 
As you can see, if you want 110 dB peaks you don't need much gain in your amp if any at all.
 
 
I don't agree with the "you need a very powerful amp" / "1W minimum" at all. It's nonsense.
If you listen to compressed music (pop, rock, metal etc.) then a fraction of this power is enough to cause serious permanent hearing damage only by listening to a few tracks.
If you listen to highly dynamic classical music, for example, then there can be short, loud peaks but on average the level will be much lower than with compressed music, so you'll never need 1W of continuous output power.
 
 
The Audeze guys speak of music with 60 dB dynamic range. That is realistic, but what's weird is that they also set the noise floor to 60 dB SPL. A 60 dB noise floor? What concert hall has a noise floor that is as loud as someone talking into your face?
Silence in a concert hall is maybe around 30 dB SPL. Even if the orchestra produced highly dynamic sound in a well-optimized concert hall with a range of 70 to 80 dB it would still only be 30 + 80 = 110 dB SPL peak.
 
 
So even if you pick the more inefficient rev2, listen to music with an annoying dynamic range of 80 dB and turn the volume up so that peaks will reach 110 dB SPL you only need about 100 milliwatts max. On average the amp won't have to output more than <10 milliwatts. The O2 outputs over 600 mW for 33 to 80 ohms.
 
 
 
edit: Only with something like the HE-6 you'll need a much more powerful amp, maybe even a speaker amp. If you read reviews of HE-6 & EF-6 you will see how bias affects what these people hear. "It's very clear sound" etc. but measurements by the German Audio magazine have shown a signal-to-noise ratio of only 75 dB. That means that fine details of the highly dynamic music mentioned above would be "overshadowed" by the noise produced by the amp.

 

[adydula]

MY LCD2's with the O2 were easily driven to ear splitting levels...
A.

 

[dclaz]

  Well sensitivity ranges from 102 (for the rev2, but we only have 1 data point) to roughly 109 dB SPL @ 1V. The ODAC outputs 2 V, so you can add 6 dB to that plus the gain of the amp.
 
As you can see, if you want 110 dB peaks you don't need much gain in your amp if any at all.
 
 
I don't agree with the "you need a very powerful amp" / "1W minimum" at all. It's nonsense.
If you listen to compressed music (pop, rock, metal etc.) then a fraction of this power is enough to cause serious permanent hearing damage only by listening to a few tracks.
If you listen to highly dynamic classical music, for example, then there can be short, loud peaks but on average the level will be much lower than with compressed music, so you'll never need 1W of continuous output power.
 
 
The Audeze guys speak of music with 60 dB dynamic range. That is realistic, but what's weird is that they also set the noise floor to 60 dB SPL. A 60 dB noise floor? What concert hall has a noise floor that is as loud as someone talking into your face?
Silence in a concert hall is maybe around 30 dB SPL. Even if the orchestra produced highly dynamic sound in a well-optimized concert hall with a range of 70 to 80 dB it would still only be 30 + 80 = 110 dB SPL peak.
 
 
So even if you pick the more inefficient rev2, listen to music with an annoying dynamic range of 80 dB and turn the volume up so that peaks will reach 110 dB SPL you only need about 100 milliwatts max. On average the amp won't have to output more than <10 milliwatts. The O2 outputs over 600 mW for 33 to 80 ohms.
 
 
 
edit: Only with something like the HE-6 you'll need a much more powerful amp, maybe even a speaker amp. If you read reviews of HE-6 & EF-6 you will see how bias affects what these people hear. "It's very clear sound" etc. but measurements by the German Audio magazine have shown a signal-to-noise ratio of only 75 dB. That means that fine details of the highly dynamic music mentioned above would be "overshadowed" by the noise produced by the amp.

 
Very insightful, thank you.

 

[Acknown3]

  Absolutely not. The HE-400 is more sensitive and efficient than the HE-500, which is not hard to drive itself.
 
With the ODAC/O2 you might even be fine with no (0 dB) gain, and less gain is better.

With that last phrase, are you saying that you should always use lowest gain settings that are loud enough for your ears?

 

[xnor]

Yes. I consider the optimal volume control range (in which you listen most of the time) to be between 10 and 2 o'clock.

 

[mcandmar]

I agree, generally speaking the less gain an amp runs the quieter it is, and less prone to distortion.  As above, if you need to wind the volume past 12 o'clock you could probably do with a bit more gain. Aim for ~50% on the volume dial as the maximum volume you will use.

 

[Acknown3]

Having less gain makes sense from a technical standpoint, but with my STX, I prefer high gain and 20% volume to medium gain and 50% volume. Could it be that I subjectively enjoy the distortion more?