With my limited understanding I have always assumed that if headphone amplifier has output impedance at least 10 times lower than the headphones load, the frequency response will be unaffected. (Provided that the amp itself has a flat frequency response)
So what has made me question my sanity are the comments amirm makes in his headphone amp reviews. For example in the review of the Apple's USB-C dongle he said:
"Switching to high-impedance 300 ohm Sennheiser HD-650 nearly killed performance. The sound was OK but bass is week and dynamic range just not there."
I understand that the little dongle probably didn't have the voltage to drive the headphones to high desibels but I can't wrap my head around that comment about bass. How can a 0.9Ohm output impedance amp affect the sound of 300Ohm headphone?
I suppose that this has something to do how different frequencies have different impedances, but this is just a guess. Can anyone enlighten me on what is going on?
Oh and another question (that is kinda the same as the first one but worded a little different):
What is this "scaling" people keep fussing about. In many reviews I see people praising the HD650 and how well it scales with high-end amps. Like how can a 300Ohm headphone that isn't even that insensitive sound different with Topping L30 vs SPL Phonitor X
Edit: Shit I posted to wrong channel
So what has made me question my sanity are the comments amirm makes in his headphone amp reviews. For example in the review of the Apple's USB-C dongle he said:
"Switching to high-impedance 300 ohm Sennheiser HD-650 nearly killed performance. The sound was OK but bass is week and dynamic range just not there."
I understand that the little dongle probably didn't have the voltage to drive the headphones to high desibels but I can't wrap my head around that comment about bass. How can a 0.9Ohm output impedance amp affect the sound of 300Ohm headphone?
I suppose that this has something to do how different frequencies have different impedances, but this is just a guess. Can anyone enlighten me on what is going on?
Oh and another question (that is kinda the same as the first one but worded a little different):
What is this "scaling" people keep fussing about. In many reviews I see people praising the HD650 and how well it scales with high-end amps. Like how can a 300Ohm headphone that isn't even that insensitive sound different with Topping L30 vs SPL Phonitor X
Edit: Shit I posted to wrong channel