Topping DX3 pro + and Sennheiser HD 600 Hi-gain vs Low-gain.

[JOCoin]

Hey all,

First post here.
Fairly new to the hobby.
A few months ago I upgraded from a Creative Sound Blasterx G6 with a pair of Beyer DT 900 pro X (48ohm) to a Topping DX3 pro + with a pair of Sennheiser HD 600 (300 ohm).

Whenever I read discussions regarding Hi-gain vs Low-gain settings on headphone amps, I always see that its recommended to run the lowest gain setting that can provide a loud enough listening experience.
But when the Topping is set to low-gain (+6 db) set at approximately -25 db output using the HD 600 the bass sounds looser and cymbals sound more veiled.
Whereas running the topping at Hi-gain (+19 db) set at around -40 db output the bass tightens up and cymbals sound much more realistic like the kit is in the same room as you.

The DT 900 Pro X sounds virtually identical with the G6 on low gain vs high gain.

Is this normal?
As I'm so new to the hobby, I'm wondering if there is an scientific explanation or if this is just in my head.
Is there a relationship between amplifier gain and headphone impedance (ohms)?

TLDR
I'm still getting a listenable volume with low-gain setting on my amp but the level of detail played back through the high impedance headphone (300) ohm is severely reduced .
Why is this?

Thanks in advance.

 

[Brian Hall]

My Sennheiser HD650 sounds great with high gain. My Sennheiser IE200 iem sounds great with low gain. Headphone amp is a Schiit Midguard.

Use the gain that sounds best to you.

 

[JOCoin]

My Sennheiser HD650 sounds great with high gain. My Sennheiser IE200 iem sounds great with low gain. Headphone amp is a Schiit Midguard.

Use the gain that sounds best to you.

I absolutely agree with you.

I was just wondering why they would sound different if the volume is roughly matched.
Mids sound very similar but the bass and treble is noticeably different/worse sounding.

I would think that if the volume is matched between low gain vs hi gain that the end result would sound the same but I don't think it does in reality.
Obviously its all subjective, but I wonder what the scientific explanation is for this as my beyer DT 900 pro X's sound pretty much the same played through a lightning dongle, creative SBX G6 and the topping DX3 pro + where as the Sennys sound different on all three.

 

[sofastreamer]

i find the high gain on my dx3pro+ to sound ever so slightly more vshaped than in low gain. definetly more treble emphasis but also a slightly deeper soundstage. i only use high gain with my 600ohm earbuds and low gain with everything else. low gain on this unit sounds less agressive to my ears.