Headphones vs Amp impedance

[dainbramage]

Hey guys,

As mentioned in earlier threads, I am on the verge of buying an RME Fireface UFX which have two unbalanced headphone outputs. Quote from the manual:

"These low impedance outputs of highest quality are able to drive headphones at
higher levels undistorted, no matter if low or high impedance headphones are used." (page 9)

So far so good. I am thinking about ordering a pair of Sennheiser HD 650 headphones with the Fireface. Their nominal impedance is @ 300ohm and the ones on the Fireface are only 30 ohm.

Quote from RME forum: "The Babyface provides 30 Ohm on the headphone outs. This could be indeed a problem with high ohm headphones." (from an administrator user)

It should be mentioned that the UFX headphone outputs have two options: high (+13dBu) and low (+2dBV) while the Babyface only has a low option.

Anyway because of this I figured I'd need a headphone amp but then I read this at another forum:
It's in the manual, it's 30 ohm, so way more than capable of handling any of those headphones. It was referring to a question on using 300 ohm headphones as well.

Is there some odd connection between output and input impedance that I'm not getting? Do they have to correlate? Or can I safely order the previously mentioned headphones along with the UFX?

 

[miroslav]

The only "problem" you might encounter with a single pair of 300 Ohm headphones is that the output level will be a tad lower than if you used phones with lower impedance.

What you have to be careful of is when it's the other way around....high impedance on the headphone amp, but low on the headphones...and then also when you stack several headphones, like might happen in a multi-person recording situation.
That "could" burn up your amp.

Basically if the total impedance of the speaker(s)/headphone(s) is higher or equal to the amp...you're OK.

 

[dainbramage]

edit: (nevermind)

you're right thanks alot miro.

btw you should upload more music to youtube. your guitar skills are amazing

 

[miroslav]

btw you should upload more music to youtube. your guitar skills are amazing

Aw shucks ... ...you're too kind.

I've been wanting to post up some more videos, but I never seem to get around to doing them. Maybe this winter...I'll have some extra time during the holidays.

 

[dainbramage]

Um now I'm considering waiting a little with the headphones and go with the more expensive Beyerdynamic T1 and they are at 600 ohm.

Will a 30ohm headphone amp (on the UFX) still not be a problem with the high setting?

Also, are those headphones really worth the extra (well, double) money of the Sennheiser HD650?

 

[miroslav]

If you have the opportunity to go to a decent music store and try out several pairs...that would be best.

Headphone sound quality and overall fit/comfort quality are a very personal thing...that's why there's always all kinds of recommendations.
Unless you're shopping for audiophile headphones for listening pleasure...you can find some $100 > models that work quite well for recording purposes where fit and isolation are key, and the sound quality mainly needs to appeal to you, so that it's not too harsh or too muddy, etc.

 

[dainbramage]

Unless you're shopping for audiophile headphones for listening pleasure...you can find some $100 > models that work quite well for recording purposes where fit and isolation are key, and the sound quality mainly needs to appeal to you, so that it's not too harsh or too muddy, etc.

I am looking for audiophile headphones for listening mostly but also for mixing and mastering. I heard that the ridiculously expensive (half a monthly wage for me) HD 800 are very revealing and accurate and might save for them. I have some closed ones for vocal recording. They're not very good soundwise (it's like work hearing protection with minijack-input) but I suppose I wouldn't sing better or worse with better sounding headphones.

I might go for the HD 800 next month then but damn what an investment, I will be near broke for a while.

 

[miroslav]

Check out the Fostex T50RP phones - can be had for well under $100.
Semi-open, not the best for vocals becuase of some bleed...but they sound great for everything else.