Hi,
I had an Asus Xonar D1 many years ago. Was the best card I've ever had in terms of SNR.
Just curious, does the impedance of your headphones match the soundcard ?
I had a Sennheiser HD515 (50 ohms) and an AKG Monitor K-141 (600 ohms).
Both worked nicely with that card. Was running XP.. 😁

Jo22 wrote:

Hi, I had an Asus Xonar D1 many years ago. Was the best card I've ever had in terms of SNR. Just curious, does the impedance of […]
Show full quote

Hi,
I had an Asus Xonar D1 many years ago. Was the best card I've ever had in terms of SNR.
Just curious, does the impedance of your headphones match the soundcard ?
I had a Sennheiser HD515 (50 ohms) and an AKG Monitor K-141 (600 ohms).
Both worked nicely with that card. Was running XP.. 😁

I have two headphones, not expensive but should be fine, one Sennheiser HD 218 and a Philips CitiScape Downtown. The first is a bit low on volume the second a bit better but still they would need even more power input. Probably the DG was pushed with a bit more amplification on the stereo output but building quality and snr sure is better on the D1!

But were your headphones connected directly to the output withou external amplificators?

Yes, I connected them directly to the D1. That was the reason why I bought it. I was looking for a quality DAC with the highest SNR and dynamic.
Around that time, the Xonar series was very young and got good critics.

There were also other external alternatives, like some uncreative products which I almost bought (thankfully not). 😈

My card was one of the early birds, I think. I never used it with anything newer than XP. Because for me, XP had the best audio engine back then (except Win 3.x for MIDI) . ^^
In XP, DirectMusic, DirectSound3D and the kernel-mixer were still intact. Recording from Stereo-Mix also still worked. 😁

The HD 218 has 24 ohms, the Pilips has 32 ohms.

The Xonar D1 has an impedance of 100 ohms, according to a post at
http://nwavguy.blogspot.de/2011/02/headphone- … -impedance.html

"It is a very late reply, but in case anyone is interested, the Xonar D1 and DX have an output impedance of 100 Ohms.
The maximum output voltage is slightly less than 2 Vrms. The card can produce the maximum output at 0 dBFS with at most
about 0.0015% distortion (based on loopback tests only, so this may be inaccurate) in the 20 Hz to 20 kHz range when loaded with 220 Ohm resistors.
With the same resistors, a 20 Hz tone is attenuated by 0.16-0.17 dB relative to 1 kHz (0.07-0.08 without a load), but this roll-off is partly due to the
AC coupled input in the loopback test. So, apparently at least some effort was made to make the output usable with headphone loads,
but the 100 Ohm impedance is generally too much. Unfortunately, these cards are often recommended for use with low impedance headphones,
without knowing or understanding the output impedance issues."

I'm no audio technican, but I think audio quality is best if both devices (card+headphones) do match in this regard.
In reality, of course, this never really is the case. What you can do is either use an external amp, turn up the volume or use a transformer.

The last one is abit special and queer, but I have done this myself for my radio hobby. 😊
I'm not sure if this does justice to hi-fidelity, but you can use a pair of audio transformers, say 1:4, 1:10 or 1:100 to correct the impedance.
I tried this several years ago to use modern headphones on a crystal radio set.
And I also tried this in reverse: I used this with my vintage crystal radio's headphones and a modern radio.

Anyway, I'm not sure what problems you have got and why the volume is so low on your card. Diagnostics like this are never easy from the far..
Perhaps it is also because the sensitivity of our heaphones are different or other electrical specs are the culprit.

Asus Xonar D1
https://www.asus.com/Sound-Cards/Xonar_D1/specifications/

Jo22 wrote:

I'm no audio technican, but I think audio quality is best if both devices (card+headphones) do match in this regard.

No, it's best when source impedance is as low as possible (voltage bridging).
This applies to amplifiers driving speakers or headphones, and also line outputs driving line inputs.

Sure, matching the impedances means maximum power transmission, but it hasn't been used in audio systems except telephones where impedance matching is required to prevent signal reflections (echo) and some early audio equipment with 600 ohm inputs and outputs.

Jo22 wrote:

Yes, I connected them directly to the D1. That was the reason why I bought it. I was looking for a quality DAC with the highest […]
Show full quote

Yes, I connected them directly to the D1. That was the reason why I bought it. I was looking for a quality DAC with the highest SNR and dynamic.
Around that time, the Xonar series was very young and got good critics.

There were also other external alternatives, like some uncreative products which I almost bought (thankfully not). 😈

My card was one of the early birds, I think. I never used it with anything newer than XP. Because for me, XP had the best audio engine back then (except Win 3.x for MIDI) . ^^
In XP, DirectMusic, DirectSound3D and the kernel-mixer were still intact. Recording from Stereo-Mix also still worked. 😁

The HD 218 has 24 ohms, the Pilips has 32 ohms.

The Xonar D1 has an impedance of 100 ohms, according to a post at
http://nwavguy.blogspot.de/2011/02/headphone- … -impedance.html

"It is a very late reply, but in case anyone is interested, the Xonar D1 and DX have an output impedance of 100 Ohms.
The maximum output voltage is slightly less than 2 Vrms. The card can produce the maximum output at 0 dBFS with at most
about 0.0015% distortion (based on loopback tests only, so this may be inaccurate) in the 20 Hz to 20 kHz range when loaded with 220 Ohm resistors.
With the same resistors, a 20 Hz tone is attenuated by 0.16-0.17 dB relative to 1 kHz (0.07-0.08 without a load), but this roll-off is partly due to the
AC coupled input in the loopback test. So, apparently at least some effort was made to make the output usable with headphone loads,
but the 100 Ohm impedance is generally too much. Unfortunately, these cards are often recommended for use with low impedance headphones,
without knowing or understanding the output impedance issues."

I'm no audio technican, but I think audio quality is best if both devices (card+headphones) do match in this regard.
In reality, of course, this never really is the case. What you can do is either use an external amp, turn up the volume or use a transformer.

The last one is abit special and queer, but I have done this myself for my radio hobby. 😊
I'm not sure if this does justice to hi-fidelity, but you can use a pair of audio transformers, say 1:4, 1:10 or 1:100 to correct the impedance.
I tried this several years ago to use modern headphones on a crystal radio set.
And I also tried this in reverse: I used this with my vintage crystal radio's headphones and a modern radio.

Anyway, I'm not sure what problems you have got and why the volume is so low on your card. Diagnostics like this are never easy from the far..
Perhaps it is also because the sensitivity of our heaphones are different or other electrical specs are the culprit.

Asus Xonar D1
https://www.asus.com/Sound-Cards/Xonar_D1/specifications/

Thanks for the info. 😀

Strange I thought the Philips would have lower volume but the Sennheiser is a bit lower. I am not saying is so low it could have a hardware problem, just lower than the DG that unfortunately I tried before the D1. Having both cards I feel like using the best so I am using the D1 but I am sure the DG has some more power even if not nearly well built as the D1.

386SX wrote:

Strange I thought the Philips would have lower volume but the Sennheiser is a bit lower.

Well I had to check the math because I am at some point purchasing new headphones.
The difference comes mainly from the sensitivity difference, and a bit from the impedance difference.

The facts:
From Sennheiser HD218 datasheet : impedance 24 ohms, sensitivity is 108 dB / Vrms.
From Philips CitiScape Downtown datasheet : impedance 32 ohms, sensitivity is 102 dB.

Note the differences in the units. Beware!

Sennheiser says you get 108dB SPL when you feed in voltage of 1 Vrms (root-mean-square).

But because Philips says nothing else about the conditions, by standard headphone measurement conditions this means you get 102 dB SPL when you feed in 1 milliwatt (1mW) of power.

OK, there are websites that do the math for you:
108 dB/Vrms @ 24 ohms is actually 91.8 dB/milliwatt.
Likewise, 102 dB/mW @ 32 ohms is actually 116.9 dB/Vrms.

So when using the same units, Philips is more sensitive than Sennheiser.
So when you feed both headphones with equal voltage or equal power, the Sennheiser is quieter and Philips louder, no matter what.

Now, because of non-zero source impedance (like 100 ohms sound card), different load impedances get different voltages. And because Sennheiser impedance is lower than Philips, to get equal voltages (or equal power) to both headphones, you need to have a higher volume setting when using Sennheiser ones and you need lower volume setting when using Philips.

OK, so what if my assumption about Philips specs was wrong and it's actually 102 dB/Vrms instead? Well, Sennheiser would be louder, but experience in previous posts say it isn't louder.

Maybe Sennheiser thought it's nicer to have a bigger number there but with different units than usual?

Jepael wrote:

Well I had to check the math because I am at some point purchasing new headphones. The difference comes mainly from the sensitiv […]
Show full quote

386SX wrote:

Strange I thought the Philips would have lower volume but the Sennheiser is a bit lower.

Well I had to check the math because I am at some point purchasing new headphones.
The difference comes mainly from the sensitivity difference, and a bit from the impedance difference.

The facts:
From Sennheiser HD218 datasheet : impedance 24 ohms, sensitivity is 108 dB / Vrms.
From Philips CitiScape Downtown datasheet : impedance 32 ohms, sensitivity is 102 dB.

Note the differences in the units. Beware!

Sennheiser says you get 108dB SPL when you feed in voltage of 1 Vrms (root-mean-square).

But because Philips says nothing else about the conditions, by standard headphone measurement conditions this means you get 102 dB SPL when you feed in 1 milliwatt (1mW) of power.

OK, there are websites that do the math for you:
108 dB/Vrms @ 24 ohms is actually 91.8 dB/milliwatt.
Likewise, 102 dB/mW @ 32 ohms is actually 116.9 dB/Vrms.

So when using the same units, Philips is more sensitive than Sennheiser.
So when you feed both headphones with equal voltage or equal power, the Sennheiser is quieter and Philips louder, no matter what.

Now, because of non-zero source impedance (like 100 ohms sound card), different load impedances get different voltages. And because Sennheiser impedance is lower than Philips, to get equal voltages (or equal power) to both headphones, you need to have a higher volume setting when using Sennheiser ones and you need lower volume setting when using Philips.

OK, so what if my assumption about Philips specs was wrong and it's actually 102 dB/Vrms instead? Well, Sennheiser would be louder, but experience in previous posts say it isn't louder.

Maybe Sennheiser thought it's nicer to have a bigger number there but with different units than usual?

Thank! This is really interesting! I remember reading somwhere about that different db measurement. Actually I think both headphones even if not high end sounds quiet good. The Sennheiser are probably more confortable to my ears cause less heat and pression but probably the Philips sounds better and louder too. Only think I don't like is the smartphone target having the not-used michropone and adapter for some phone. (without it sounds is bad with some source).