[Corvin25]

Hi. I've been popping on and off of this forum over the years whenever I need a second opinion about gear!

Right now I'm using a pair of Beyerdynamic 250 Ohm DT 770 PRO headphones. Meaning I had to upgrade my sound card a couple years ago (Sound Blaster Z) to make full use of them.

But lately I've been testing them against my Audio Technica ATH-M50X, and I seem to be getting a much more powerful and punchy sound out of them than I am with my DT770s.

The DTs are significantly more expensive (I've had them a year now), and all the review sites I've visited almost unanimously agree that the DTs are flatly superior to the M50x... So why do the DTs sound weaker to me?

I'm using a dedicated sound card, the Sound Blaster Z. Creative CLAIMS that there is a headphone amp in it that supports up to 600 Ohm headphones. But it is a pretty old card, and the interface isn't exactly on par with current solutions.

So what should I do to make my DTs sound as good or better than my M50x? Do I scrap the sound card completely and get an external DAC/AMP, or should I invest in an amplifier in ADDITION to my sound card?

...Or am I doing something very wrong?

 

[ADUHF]

You're not doing anything wrong.

The 250-ohm DT-770 is harder to drive to high volumes than the 38-ohm AudioTechnica M50x. That's generally the case with higher impedance headphones. To compare the loudness of two headphones though, you really need to look at their sensitivity in dB/V SPL.

A quick Google of these two headphones tells me that the 250-ohm DT-770 has a sensitivity of about 100 dB/V SPL. And the AT M50x has a sensitivity of about 115 dB/V. So a difference of about 15 dB/V. That means that the M50x is perceptually more than twice as loud as the 250-ohm DT-770 when receiving the same input voltage from your sound card. Because a difference of 10 dB is about 2x the perceived volume.

Do not confuse sensitivity in dB/V SPL with efficiency in dB/mW SPL. Because these are two different (but related) things. And mfrs will often confuse the two. The dB/V rating gives you a better idea of a headphone's perceived loudness with the same signal.

The loudest headphone I've heard lately is the AKG K371 btw, which is also spec'd at around 114 dB/V SPL. The K371's actual measured sensitivity is reportedly somewhat higher though, and more around 120 dB/V. And my ears seemed to confirm that in side-by-side comparisons with other similar headphones.

 

[ADUHF]

There are differences in the tonal balance of the two headphones as well. The DT-770 is brighter in the treble. While the M50x has a bit more emphasis in the upper bass...

250-Ohm DT-770 Frequency Response:
COMPENSATED (Left & Right): https://www.rtings.com/headphones/1-4/graph#440/3992
RAW (Left): https://www.rtings.com/headphones/1-4/graph#440/4011
RAW (Right): https://www.rtings.com/headphones/1-4/graph#440/4012

M50X Frequency Response:
COMPENSATED (Left & Right): https://www.rtings.com/headphones/1-4/graph#295/3992
RAW (Left): https://www.rtings.com/headphones/1-4/graph#295/4011
RAW (Right): https://www.rtings.com/headphones/1-4/graph#295/4012

So they will sound a bit different even when adjusted to roughly the same perceived volume.

 

[ADUHF]

The M50x and 250-ohm DT-770 were both designed primarily for use as studio beaters. But they were engineered for somewhat different purposes.

The M50x is more of a general purpose headphone that will work with both low impedance portable devices, and also higher impedance studio gear. Because of its higher volume and low impedance though, it will probably sound a little better with a lower impedance amp, like you would find on most portable devices.

The 250-ohm DT-770 is designed more for clarity and detail. Especially higher frequency detail. And also the higher impedance amplifiers in studio gear. It can work with lower impedance amps as well. But requires a bit more power to reach a decent volume with them. And needs more equalization to smooth out its overall response, particularly in the treble, to produce a warmer, more pleasing/satisfying, and less analytical sound for music listening. This is something I've been working on for my own pair (see my sig).

The M50x also needs equalization as well imo, to smooth out some of the unevenness in it response in various spots. And both headphones also have a somewhat V-shaped sound due to a depression in their lower midrange/upper bass, and somewhat brightly tilted upper-mids. And extra emphasis in some spots in the bass and treble.

This brighter tilt in the mids is somewhat easier to see on the raw frequency plots above. Compare those raw plots above to a headphone with more darkly-tilted mids, like the Bose Soundlink On-Ear headphones. Which is probably somewhat closer to the sound of alot of popular on-ear and in-ear consumer headphones. And there is quite a difference!...

https://www.rtings.com/headphones/1-3-1/graph#313/3182
https://www.rtings.com/headphones/1-3-1/graph#313/3183

The midrange frequencies, ranging from the high bass to the low treble, are probably the most important frequencies in a headphone's sound, because that is where the majority of the audio content resides in most recordings. Bass and treble are also important. But a headphone's sound is, to a large extent, determined by the coloration in its midrange frequencies. So a headphone with a somewhat more neutral tuning in the midrange, perhaps somewhere more in between the sounds of the Bose and the Beyer/AudioTechnica, will probably be a bit better for general music listening.

 

[Corvin25]

You're not doing anything wrong.

The 250-ohm DT-770 is harder to drive to high volumes than the 38-ohm AudioTechnica M50x. That's generally the case with higher impedance headphones. To compare the loudness of two headphones though, you really need to look at their sensitivity in dB/V SPL.

A quick Google of these two headphones tells me that the 250-ohm DT-770 has a sensitivity of about 100 dB/V SPL. And the AT M50x has a sensitivity of about 115 dB/V. So a difference of about 15 dB/V. That means that the M50x is perceptually more than twice as loud as the 250-ohm DT-770 when receiving the same input voltage from your sound card. Because a difference of 10 dB is about 2x the perceived volume.

Do not confuse sensitivity in dB/V SPL with efficiency in dB/mW SPL. Because these are two different (but related) things. And mfrs will often confuse the two. The dB/V rating gives you a better idea of a headphone's perceived loudness with the same signal.

The loudest headphone I've heard lately is the AKG K371 btw, which is also spec'd at around 114 dB/V SPL. The K371's actual measured sensitivity is reportedly somewhat higher though, and more around 120 dB/V. And my ears seemed to confirm that in side-by-side comparisons with other similar headphones.

Thank you for the responses!

Hmm. I THINK I understand... sorta... So I guess that means that the sound volume/quality will be comparable the louder I set the volume for the DT-770... because the M50x gets louder exponentially faster, since they require significantly less power?

Do I have that about right?

Also, I've tweaked the Sound Blaster Z settings to be similar to a Winamp EQ setting I like, so I think that made quite a large difference in sound quality.

 

[ADUHF]

Thank you for the responses!

Hmm. I THINK I understand... sorta... So I guess that means that the sound volume/quality will be comparable the louder I set the volume for the DT-770... because the M50x gets louder exponentially faster, since they require significantly less power?

Do I have that about right?

I think you've got the general idea. The M50x will always be louder than the DT-770 when used on the same amp at the same volume setting, because the M50x is the easier of the two headphones to drive. And there's really no way for you to change that. (See my next post below though re different gain settings as a possible solution for this.)

This is getting a little into the weeds. But technically speaking, there are really two ways of boosting the volume on both headphones. One is to use a low impedance amp with more power. And the other is to use an amp with a higher output impedance. The M50x is more likely to sound distorted than the DT-770 on a higher impedance amp though, like you might find on alot of pro audio gear. So the low impedance amp with more power is probably the better way to go, if you intended to use it with a variety of different headphones.

The DT-770 will always be lower in volume. But it will always have less distortion as well, and generally better clarity and detail than the M50x, due to its higher impedance and damping factor...

https://en.wikipedia.org/wiki/Damping_factor
https://en.wikipedia.org/wiki/Impedance_bridging

That's what the specs on the two headphones suggest anyway. YMMV though.

 

[ADUHF]

I don't really know that much about the ins and outs of sound cards btw. But you might check to see if there is a different gain setting on your card for use with higher impedance headphones. Many dedicated headphone amps will have a low and high gain switch, or sometimes multiple gain settings to broaden their compatibility with different headphones.

If the card has a high gain setting, you could try that with the 250-ohm DT-770, and see if it brings the volume up closer to the M50x on the low gain setting.

 

[ADUHF]

From looking at a couple others posts and threads on this topic, it appears that some of the older Sound Blaster Z cards did not, in fact, have a gain switch. So that might be one possible reason to consider either an upgrade, or a separate amp.

It seems as though more people were having problems with the SBZ being too loud on their lower impedance headphones, rather than the other way around. Here's one example...

https://www.head-fi.org/threads/sound-blaster-z.695232/

And it looks like the output impedance on this card may actually be on the higher side at 22 ohms. Which would tend to make it more compatible with a higher impedance headphone like the 250-ohm DT-770. And possibly overly loud, and more distorted on a low impedance headphone, like the M50x.

So if you got a different card with different gain settings, it might actually improve the sound more on the M50x, by delivering a lower impedance to it, if that makes any sense. And maybe do little or nothing to improve the sound of the 250-ohm DT-770.

The Equalizer APO fix mentioned in the above link will do nothing to change the card's output impedance btw. So I wouldn't really recommend using it as solution to this particular problem. Except maybe as a temporary stop-gap to bring down the volume to a more manageable level for the M50x. (I am currently trying the Equalizer APO as the EQ though for my 250-ohm DT-770, and have posted a few tips on how to use its Graphic EQ feature here, in case you're interested.)

For best sound quality, the M50x and other lower impedance headphones like it really need an amp or soundcard with an output impedance a bit closer to 1 ohm.