Doubt about maximum impedance for my audio interface

[Piereligio]

Hi all, I'm considering to take a headphone for studio recording, I actually have an Icon Aio 6 audio interface, here the technical specifications. http://iconproaudio.com/product/aio-6/
Now, I see two difference impedances reported for the headphones outputs.

75 Ohm

32 to 600 Ohms

[td=colspan:2]Output Impedance[/td] [td=colspan:2]Load Impedance[/td]

I'm in doubt: what value is the one I should be "worried" about? The headphone I was thinking to take is the beyerdynamic dt 990 pro, it is 250 Ohms.

 

[ProtegeManiac]

Quote:

Originally Posted by Piereligio /img/forum/go_quote.gif

Hi all, I'm considering to take a headphone for studio recording, I actually have an Icon Aio 6 audio interface, here the technical specifications. http://iconproaudio.com/product/aio-6/

Now, I see two difference impedances reported for the headphones outputs.

75 Ohm

32 to 600 Ohms

[td=colspan:2]

Output Impedance [/td] [td=colspan:2]

Load Impedance [/td]

I'm in doubt: what value is the one I should be "worried" about? The headphone I was thinking to take is the beyerdynamic dr 990 pro, it is 250 Ohms.

 

Load impedance typically needs to be a lot higher - safe ratio is 8x higher - than output impedance. This becomes less important the higher the load impedance though, so as far as these impedances are concerned I wouldn't really worry about your headdphones and this interface.

What I would worry about though is whether the headphone sensitivity wouldn't need a lot more power than what the interface can spit out at 250ohms, but I wouldn't worry about it too much. If it makes its power at lower impedance then given the 90mW at 100ohm rating it would theoretically make less than 45mW at 250ohms. At low volume you should have enough clean enough power with some in reserve, but don't expect to be able to crank it up for when you're listening and hit your favorite tracks. 

 

Overall though there are interfaces with lower power out there and given you have this one might as well use it. If anything, look into the T70 - it has a much higher sensitivity and it has a 300ohm version.

 

[Piereligio]

 

 

Load impedance typically needs to be a lot higher - safe ratio is 8x higher - than output impedance. This becomes less important the higher the load impedance though, so as far as these impedances are concerned I wouldn't really worry about your headdphones and this interface.

What I would worry about though is whether the headphone sensitivity wouldn't need a lot more power than what the interface can spit out at 250ohms, but I wouldn't worry about it too much. If it makes its power at lower impedance then given the 90mW at 100ohm rating it would theoretically make less than 45mW at 250ohms. At low volume you should have enough clean enough power with some in reserve, but don't expect to be able to crank it up for when you're listening and hit your favorite tracks. 

 

Overall though there are interfaces with lower power out there and given you have this one might as well use it. If anything, look into the T70 - it has a much higher sensitivity and it has a 300ohm version.

Could you reccomend me an open headphone, with the most fidelity possible, under 70 Ohms (to be safe) and 250€? I was thinking to AKG k701.

 

[PurpleAngel]

  Could you recommend me an open headphone, with the most fidelity possible, under 70 Ohms (to be safe) and 250€? I was thinking to AKG k701.

 
The 62-Ohm AKG K701 is slightly more power demanding then a 250-Ohm Beyerdynamic headphone.
 
If your into Audio Creation/recording, Believe it's better to use neutral (boring?) headphones.
You might check out the Sony MDR-V6 or MDR-7506, they are popular studio monitoring headphones, 
They sell for under 100 Euros

 

[Piereligio]

   
The 62-Ohm AKG K701 is slightly more power demanding then a 250-Ohm Beyerdynamic headphone.
 
If your into Audio Creation/recording, Believe it's better to use neutral (boring?) headphones.
You might check out the Sony MDR-V6 or MDR-7506, they are popular studio monitoring headphones, 
They sell for under 100 Euros

Why is the AKG K701 more power demanding?

 

[PurpleAngel]

  Why is the AKG K701 more power demanding?

 
Ohm is not the only factor for the power demands of a headphone.
There is also sensitivity, the less sensitive the headphone, the more power it needs 

 

[Piereligio]

   
Ohm is not the only factor for the power demands of a headphone.
There is also sensitivity, the less sensitive the headphone, the more power it needs 

Oh, yes, I know. I just didn't expect big differences between headphones about that value.

 

[jodgey4]

 

 

 This becomes less important the higher the load impedance though, so as far as these impedances are concerned I wouldn't really worry about your headdphones and this interface.

 
Hmm. I'm not sure this is true. The 1/8 helps make sure there aren't any changes in sound signature due to the headphone's varying impedance across frequency. A higher damping factor also helps with electrical damping.

However, I think this issue is usually overblown. And the DTxx0 series also is an old studio standard that probably was developed with high device output impedances in mind - as is common on studio headphone amplifier gear from what I've been told. I think you should be fine, though you might be a little starved for power. You can always add an additional amp later. There's plenty of amps under $150 that would really be great, should you ever decide to go that route .

  Oh, yes, I know. I just didn't expect big differences between headphones about that value.
 
EDIT: The beyerdynamic is 96dB, the AKG 105dB. Doesn't higher sensitivity mean that you have more dB with the same wattage (they usually measure that value with 1mW if I'm right)?

The 96 and 105 might be measured differently. IME, the K7xx variants are just as hard to drive as DT990s, maybe indeed a touch harder.

 

[Piereligio]

   
Hmm. I'm not sure this is true. The 1/8 helps make sure there aren't any changes in sound signature due to the headphone's varying impedance across frequency. A higher damping factor also helps with electrical damping.

However, I think this issue is usually overblown. And the DTxx0 series also is an old studio standard that probably was developed with high device output impedances in mind - as is common on studio headphone amplifier gear from what I've been told. I think you should be fine, though you might be a little starved for power. You can always add an additional amp later. There's plenty of amps under $150 that would really be great, should you ever decide to go that route .
The 96 and 105 might be measured differently. IME, the K7xx variants are just as hard to drive as DT990s, maybe indeed a touch harder.

I think they used different measurement units, now that I checked better. For the DT I found dB sensitivity, for the AKG an SPL/V value. 
I'd prefer an open headphone though...
I'd like a headphone for mixing, more than for recording (I actually don't use headphones at all for recording, just some improvised speaker or in ear earphones after setting well the plugins and effects using headphones).

 

[ProtegeManiac]

Quote:

Originally Posted by Piereligio /img/forum/go_quote.gif

Could you reccomend me an open headphone, with the most fidelity possible, under 70 Ohms (to be safe) and 250€? I was thinking to AKG k701.

 

I just explained to you how a higher impedance is a lot better to use on that interface. Not to mention that some lower impedance headphones have even lower sensitivity, and that includes the K701 which I think is 3dB less efficient than the DT990. That doesn't seem like a lot but decibel and power graphs are logarithmic, not linear. Even if your interface is producing a lot more power at 62ohms than at 250ohms it is not going to get the K701 louder with less distortion than a higher impedance, higher sensitivity headphone. On top of that now you'll have to deal with the lower damping factor, so it will be a gamble on whether you get a bass that sounds like a mudslide or barely audible but still inarticulate bass.

  EDIT: The beyerdynamic is 96dB, the AKG 105dB. Doesn't higher sensitivity mean that you have more dB with the same wattage (they usually measure that value with 1mW if I'm right)?

 
Those are measured differently. One is sensitivity and the other is efficiency, which in technical terms are very different but for practical purposes as long as you're comparing the same unit it doesn't matter. The comparable rating for the K701 is 93dB.

 

[jodgey4]

According to InnerFidelity, the DT880 250-ohm (similar to the DT990 driver-wise), it takes 0.23mW to reach 90dB. So, 230mW to reach 120dB peaks. The K701 takes 1.20mW for 90dB, or 1.2W for 120dB peaks. At ~250 ohms vs 70 ohms, and assuming a perfect voltage amp, the K701 is harder to drive (a headphone of an impedance 3x that of another should receive 1/3 the power). Worth noting, the K7XX does better, needing only 1/2 the power of the K701.

Tl;dr - the K7XX is an easier option to drive compared to the K701. And they're both still pretty danged hard to drive, when compared to the DTXX0-250ohm series.

 

[Piereligio]

 

 

I just explained to you how a higher impedance is a lot better to use on that interface. Not to mention that some lower impedance headphones have even lower sensitivity, and that includes the K701 which I think is 3dB less efficient than the DT990. That doesn't seem like a lot but decibel and power graphs are logarithmic, not linear. Even if your interface is producing a lot more power at 62ohms than at 250ohms it is not going to get the K701 louder with less distortion than a higher impedance, higher sensitivity headphone. On top of that now you'll have to deal with the lower damping factor, so it will be a gamble on whether you get a bass that sounds like a mudslide or barely audible but still inarticulate bass.
 
Those are measured differently. One is sensitivity and the other is efficiency, which in technical terms are very different but for practical purposes as long as you're comparing the same unit it doesn't matter. The comparable rating for the K701 is 93dB.

In few words you're reccomending me to try the dt990? I can always give it back with no costs, I'd take it with amazon prime.

 

[ProtegeManiac]

  In few words you're reccomending me to try the dt990? I can always give it back with no costs, I'd take it with amazon prime.

 
To be more precise, what I am saying is that I would much sooner get the DT990 than any of the AKGs if you're using that interface. Just look at the more precise quantitative explanation by jodgey4.
 
Ideally though I'd get the T90 - the sensitivity is even higher than the DT990.
https://www.amazon.com/dp/B00KCML1FO/ref=dp_cerb_1

 

[Piereligio]

To be more precise, what I am saying is that I would much sooner get the DT990 than any of the AKGs if you're using that interface. Just look at the more precise quantitative explanation by jodgey4.

Ideally though I'd get the T90 - the sensitivity is even higher than the DT990.
https://www.amazon.com/dp/B00KCML1FO/ref=dp_cerb_1

These ones cost very much. I'll be happy with the dt990, I think. They're just 140€.

 

[Piereligio]

   
To be more precise, what I am saying is that I would much sooner get the DT990 than any of the AKGs if you're using that interface. Just look at the more precise quantitative explanation by jodgey4.
 
Ideally though I'd get the T90 - the sensitivity is even higher than the DT990.
https://www.amazon.com/dp/B00KCML1FO/ref=dp_cerb_1

Sorry for still bothering you. In your opinion, how many dB could I get using the dt990 (96 dB/mW, 250 ohms) on the interface (90 mW into 100 ohms, 75 ohms load impedance) I have?