[Prizm]

Just got the HD590s after a lot of research and reading reviews. These are awesome! The full open-back really makes the sound more realistic - almost like it's coming from speakers in a lounge room instead of inside your head (or a tin can).

I got them for the PC because I do a lot of sound editing and such, and needed comfort for long sessions as well as detail in the sound.
I already notice a big difference - I'm able to pick out distortion that I couldn't detect previously with the AKG K-66's I've been using.

Now - I've got the Yamaha YST-MS55D 2.1 speaker system for my PC (Yamaha's top PC speakers AFAIK), and read in the manual that the headphone output for these speakers is 30 ohms??

Is that the impedance?? If so, it's rather low isn't it?
Out of interest, I checked my discman manual, and the headphone output for the discman is 16 ohms.

So my question is - is that correct? If the impedance of the HD590s is 120 ohms, does that mean the output level of the headphone jack you plug it in to should preferably equal 120 ohms or more?

Would it be better if I plug the headphones straight into my SBLive? I figured since my speakers are powered, they would be my best bet, but now I don't know.

Prizm

 

[Pace]

I've got the HD590's too and I use them on my Logitech Z-560's headphone out. They sound better through it than directly from the sound card. I'm planning on buying a dedicated amp for the 'phones though.

SB Live! might be capable enough to drive the HD590's alone, but test the headphone out of the Yamahas aswell. Unfortunately Live! isn't the highest of quality when it comes to sound quality so upgrading your sound card in the future might be a wise move aswell as getting a seperate amp for the headphones.

 

[DarkWolf]

I've been looking at the 590s too. I hope to buy a pair along with an HA-1 from Jan. I say hope because my plans might go askewed when all the reviews of th new AT phones start pooring in. But that's not the point here, I was going to give you advice on he sound card side. I listen to a lot of music off my computer and I had come to the conclution that the SB Live had to go. I bought a Terratec DMX 6-Fire and it made a world of subtle differences. Anything and everything the SB did, this does better. This also can do some cool stuff the SB didn't. If you are doing sound editing and such, you really ought to get a better card, especialy since you have good speakers and good headphones. This card goes for $250, so it's a little steep, but it also has a great breakout box, which may apeal to you. If not there is a "Light" version with no box and an extra back slot for digitl I/O, this version is around $170. If that's still too much I think you can get a similar but slightly more scaled down offering from M-Audio for around $100, but I'm not sure about that. Bottom line is that a high quality card will make a big difference for you. With my card the clarity is much better, witrh the SB it had sort of an audio plack over all the sounds, it was hard to describe, like looking out at the world throught the screen window of a tent.. The new card also does a MUCH better job of opening the sound up and placing certain things. (If you game at all, this can give you an edge too.) The box has a 1/4" headphone jack on the front with a volume knob, which I use for my current bad headphones, but I don't know how good it really is. It's obviously got a great card behind it, but I don't know what it's power rating is.
Anyway, have fun and I'm glad you like the 590s. Have you broken them i yet? How muc difference did it make?

 

[Pace]

Quote:

Originally posted by DarkWolf ... I listen to a lot of music off my computer and I had come to the conclution that the SB Live had to go. I bought a Terratec DMX 6-Fire and it made a world of subtle differences...

As a former owner of Live! and current owner 6fire LT I can totally agree with this comment.

 

[wallijonn]

don't worry about the 30 ohms impedence. it's almost a standard.

the 120 ohm headphone will not be driven to as high a volume level as if it were connected to a 120 ohm jack.

don't be afraid to experiment by connecting the hd590's into the SB output (you may want to compare what it sounds like when it's set to "headphone" instead of "speakers" in the AudioHQ applet in the control panel).

Enjoy your purchase. It should sound very nice with audio cd's and mp3's.

 

[gdahl]

Okay, here are some basics about headphone impedance...

A headphone's impedance determines how much current it will draw at a particular signal voltage and frequency.

Since the impedance is not constant with frequency, the manufacturer plots an impedance curve and specifies a nominal value. This nominal value isn't really an average, but more like what I would call an "average minimum", a figure below which the actual impedance doesn't drop significantly.

Input impedance can be understood on an intuitive level if you consider the feeling of changing gears on a bicycle. If you shift into a higher gear, it is harder to push but you go farther for each turn of the crankset. This is what the amp "feels like" driving a high impedance. It works just fine as long as it has enough voltage ("tension") to do the work. If you shift into a lower gear, it is easier to push but you have to turn the crankset faster to go the same speed. This is what the amp "feels like" when it has to deliver current. If it has enough current capacity it can stay out of trouble. But think about what happens if you shift into too low a gear at high speed--your legs can't turn the crank fast enough to keep up with the gears. This is what happens to the amp if it can't supply the current demand.

If we had such thing as a perfect amplifier, impedance wouldn't matter. A perfect amplifier would have zero output impedance and infinite output current capacity. In that case, the impedance curve of the headphone would be of essentially no consequence. Signals at lower-impedance frequencies would draw more current, while signals at higher-impedance frequencies would draw less current. But this would have no effect on frequency response.

Of course we don't have such thing as a perfect amplifier. Now we must consider the output impedance of the amp.

Output impedance is basically a measure of how hard it is for it to drive its own output. This can be illustrated intuitively by returning to the bicycle example, but this time considering the interface between the bicycle and the road, so now the bicycle is the output device (instead of the rider).

Once again, being in a high gear is analagous to having a high output impedance. In this case it is hard to make a sudden change in speed, which would correspond to instantaneous current demand into a low impedance. Change to a lower gear, and you can respond much more quickly, unless you run into a situation where your legs can't keep up ("running out of current".)

Output impedance is measured by evaluating the output voltage measured across different-value loads. The higher the output impedance, the greater the change. This means that if you drive a headphone with an amp of relatively high output impedance, the frequency response will vary in accordance with the impedance curve of the headphones. As the output impedance of the amp is lowered, the magnitude of this effect decreases.

A typical solid-state headphone output will have very low output impedance, probably less than one ohm. Most headphones have a nominal impedance of somewhere between a few tens and a few hundreds of ohms. At first this would seem to be a reasonable impedance relationship (low output impedance driving high input impedance). However, lesser-quality amps may have trouble driving headphones whose impedance lies near either extreme--it may have trouble developing enough voltage to drive a high-impedance headphone, or it may run out of current trying to drive a low-impedance headphone.

I'll save the discussion of tube amps for another time.

Hope this helps!

 

[Eagle_Driver]

To add to the problems of crappy amps not being able to develop enough voltage or current, the end result of running out of voltage is that nasty clipping distortion that can sometimes burn out headphones. And the amp itself running out of current will usually result in a dull, lifeless, murky sound.

Another thing to consider is the current capacity of the power supply that's driving the amp. If that power supply is crappy to begin with, it won't be able to supply the current that's needed for the amp to drive extremely low-impedance headphones. The end result is overheating, and - once again - that nasty clipping distortion, because it will be the power supply itself (and not the amp) that will be running out of current capacity.