Hifiman Sundara 2 issues: 1, volume levels, 2, noise floor. help?

[Shubhashish]

hey guys,

I got myself my first pair of audiophile grade headphones yesterday -- Hifiman Sundara. I am a bit perplexed about a couple of issues and need your perspective. Please help a fellow noob with these issues and help me get better?

Okay, so a bit of a background. I have a hidizs S9 Pro AMP/DAC that I use with my Macbook Air. Till now, I was listening to music using this setup on my Sony WH- H910n. Now, there's an earthing issue with the two-pin charging plugs that Apple sells with their Macs in my country so every time the laptop is charging there's a current leak that one can feel on the palms resting on either side of the trackpad. This current leak causes noise floor when listening to music on the Sony headphones via Hidizs Amp.

As I said earlier, I got Hifiman Sundaras yesterday.

Two things happened.

1. I have to listen to music at a higher volume than what I did with my Sonys. Does this mean the Hidizs amp isn't able to drive Sundaras as well as it did to my Sony? Like usually on the Sony, three bars on the sound level would be more than sufficient but with the Sundaras I have to crank volume up to half to get the same audio level.
2. I can't hear the noise floor when listening to music via Hidizs amp on my Sundara headphones while the laptop is charging. This noise floor was very audible when I listening to music on my Sony WH-H910n while charging the laptop. I am not complaining as noise floor was obviously a mood-killer. But does this mean the Sundaras aren't as sensitive as the Sony WH-H910n?

Please help me clear these doubts guys.

Thanks!

 

[solderdude]

1. I have to listen to music at a higher volume than what I did with my Sonys. Does this mean the Hidizs amp isn't able to drive Sundaras as well as it did to my Sony? Like usually on the Sony, three bars on the sound level would be more than sufficient but with the Sundaras I have to crank volume up to half to get the same audio level.
2. I can't hear the noise floor when listening to music via Hidizs amp on my Sundara headphones while the laptop is charging. This noise floor was very audible when I listening to music on my Sony WH-H910n while charging the laptop. I am not complaining as noise floor was obviously a mood-killer. But does this mean the Sundaras aren't as sensitive as the Sony WH-H910n?

Yes, this all has to do with sensitivity.
Headphones all have a different sensitivity meaning they do not play equally loud at the same input voltage level (volume control position)

 

[Shubhashish]

Yes, this all has to do with sensitivity.
Headphones all have a different sensitivity meaning they do not play equally loud at the same input voltage level (volume control position)

Thanks! 1 follow up. Does this mean Sony Wh-H910n are more sensitive than Hifiman Sundaras? If that's true, which is a better headphone? The one which is more sensitive? From what I gather (Please correct me), that if Sony Wh-H910n is picking up noise floor then its more sensitive than Sundaras. And more sensitive means they have more detailed music reproduction.

 

[solderdude]

Yes, the Sundara is not what one would call a sensitive headphone (104dB @ 1V).
Sony is 112dB @ 1V (passive, so switched off and is 18 ohm) or 113dB @ 1V (50 ohm) when switched on using a wired connection.
The Sony thus plays almost twice as loud from the same volume control level position.

This has nothing to do with quality though. Just that one is more sensitive than another.
Sensitivity = dB loudness per applied voltage it has nothing to do with details in music etc.
The latter is related to frequency response, which, ultimately is a different sensitivity at various frequencies.
In general, sensitivity numbers/measurements are done at either 400Hz, 500Hz, 1kHz or using narrow-band noise so numbers may vary.

When a headphone has a +6dB bass boost for instance the sensitivity of that headphone is 6dB higher in the bass than at 1kHz (for instance).

 

[D00M]

Hi OP, Sony WH-H910n is bluetooth wireless headphone. I assume you are listening to it thru the bluetooth, or using USB connection to the headphone. The sound level discrepancy between Sony and Sundara is not apple-to-apple comparable. In this mode, Sony is using the built in DAC/Amp of the headphone, whereas Sundara is using external DAC/amp. Sundara has more details and wider soundstage. Sony has dull sound, bloated bass, and zero sound stage (sound is coming from a point source in between your ears). Depending on your preference or what you are used to, it might take some time to realize the advantage of Sundara. A bit suprised that you think WH-H910n is more sensitive, therefore will be more detailed... I hope your ears can pick up the difference.

You should not be using Sony WH-H910n passively (using external DAC/amp) and feeding the headphone using analog audio cable, because it will sound like AM radio. Not just a problem with Sony WH-H910n, but issue with many bluetooth headphones.

I purchased Sony WH-H910n for USD $110 at Costco at beginning of Covid. Since I was working from home, I wanted a headset to do Webex meetings. I figured I can just get a cheaper bluetooth headset. Because I'm used to the mid-fi sound of other headphones, I had to return Sony WH-H910n. There is no way I will use it for music or movies. And for Webex meetings, Apple's free earbuds sound better than Sony WH-910n.

 

[Shubhashish]

Hi OP, Sony WH-H910n is bluetooth wireless headphone. I assume you are listening to it thru the bluetooth, or using USB connection to the headphone. The sound level discrepancy between Sony and Sundara is not apple-to-apple comparable. In this mode, Sony is using the built in DAC/Amp of the headphone, whereas Sundara is using external DAC/amp. Sundara has more details and wider soundstage. Sony has dull sound, bloated bass, and zero sound stage (sound is coming from a point source in between your ears). Depending on your preference or what you are used to, it might take some time to realize the advantage of Sundara. A bit suprised that you think WH-H910n is more sensitive, therefore will be more detailed... I hope your ears can pick up the difference.

You should not be using Sony WH-H910n passively (using external DAC/amp) and feeding the headphone using analog audio cable, because it will sound like AM radio. Not just a problem with Sony WH-H910n, but issue with many bluetooth headphones.

I purchased Sony WH-H910n for USD $110 at Costco at beginning of Covid. Since I was working from home, I wanted a headset to do Webex meetings. I figured I can just get a cheaper bluetooth headset. Because I'm used to the mid-fi sound of other headphones, I had to return Sony WH-H910n. There is no way I will use it for music or movies. And for Webex meetings, Apple's free earbuds sound better than Sony WH-910n.

Thank you for your detailed reply. I am listening to the Sonys wireless and wired, both. I fully agree with you that Sundara is more detailed and wider soundstage. Sony is dull and zero sound stage. I use Hidizs S9 Pro with both the headphones.

The reason I said I feel Sony is more sensitive is because it catches the noise floor when I am plugging it to my Mac while the laptop is on charge. But no such noise is heard when I listen to Sundaras. The noise floor while charging the Mac is an earthing issue that I need to resolve anyway.