[Music Alchemist]

  The first variable to isolate away is your perception, until you have the data in hand.

 
When it's an obvious difference, like a lot more bass with the amp, "data" is unnecessary. I was referring to only testing with and without a DAC, instead of testing with and without a DAC and amp.

 

[RRod]

   
When it's an obvious difference, like a lot more bass with the amp, "data" is unnecessary. I was referring to only testing with and without a DAC, instead of testing with and without a DAC and amp.

 
The amp should only have more bass if there is some kind of impedance mismatch or it's deliberately colored. In either case I don't see why new tracks would suddenly make it obvious where it wasn't before. Since this is Sound Science, I feel justified saying "if it ain't done blind, it ain't done period." 

 

[Music Alchemist]

  The amp should only have more bass if there is some kind of impedance mismatch or it's deliberately colored. In either case I don't see why new tracks would suddenly make it obvious where it wasn't before. Since this is Sound Science, I feel justified saying "if it ain't done blind, it ain't done period." 

 
Yeah, well, I do plan on more serious tests in the future when possible. I only tested a few songs before, but after that, I listened for longer periods where on some songs, the differences were more apparent. As for amps and bass, it has been well-documented that some headphones have stronger bass when amplified.

 

[RRod]

   
Yeah, well, I do plan on more serious tests in the future when possible. I only tested a few songs before, but after that, I listened for longer periods where on some songs, the differences were more apparent. As for amps and bass, it has been well-documented that some headphones have stronger bass when amplified.

 
You're talking about comparing two amps, and if the two amps have a flat frequency response, no impedance issues, and can both sufficiently drive the headphones, why would you hear more bass?

 

[Music Alchemist]

  You're talking about comparing two amps, and if the two amps have a flat frequency response, no impedance issues, and can both sufficiently drive the headphones, why would you hear more bass?

 
You mean comparing to the weak amp in my laptop?

 
I'm assuming you know that amplification is not just about loudness. For example, you can get plenty of loudness for the HiFiMAN HE-6 from a weak amp, but the sound quality will be comparatively awful without something much more powerful.
 
Anyway, don't ask me. I'm not a tech guy. Lots of people talk about how a more powerful amp delivers more powerful bass with some headphones. Go ask them for the details. But when you hear much less bass even when cranking the volume to uncomfortable levels, you know there is a difference.
 
@cel4145
Perhaps you could offer insights here?

 

[cel4145]

If amp B delivers more powerful bass than amp A, probably means amp A wasn't powerful enough to drive the headphones.

 

[Music Alchemist]

If amp B delivers more powerful bass than amp A, probably means amp A wasn't powerful enough to drive the headphones.

 
It's just that you mentioned to me in the past that some headphones need more power than some people think. But yeah, it doesn't feel like my laptop's built-in amp is powerful enough to bring the best out of my headphones. I don't even get enough volume with some songs. Still sounds good, though.

 

[cel4145]

It's just that you mentioned to me in the past that some headphones need more power than some people think. But yeah, it doesn't feel like my laptop's built-in amp is powerful enough to bring the best out of my headphones. I don't even get enough volume with some songs. Still sounds good, though.

I think some people don't listen to bass heavy music. So the headphones sound good to them with an amp because it's only having to drive mids and highs. Add in a lot of midbass and subbass, and that's more audio having to be amped.

 

[bigshot]

Enough is enough. It's more a matter of the headphones than the amp. My Oppo PM-1s are fine unamped. Amping doesn't change them at all.

 

[stv014]

As for amps and bass, it has been well-documented that some headphones have stronger bass when amplified.

 
Everything has stronger bass at higher loudness. Did you level match the amplifiers ?
 
Other than that, it is actually quite possible for onboard headphone outputs to have audible issues with bass response, and it is not because of lack of power. They often have rather high output impedance (the Realtek datasheets recommend up to 75 ohms external resistors for some codec chips), although that is more likely to increase bass levels with full size headphones, at the expense of somewhat increased distortion. The outputs are also frequently capacitor coupled, with the datasheets suggesting 100 uF capacitors for the headphone jack, and 4.7-10 uF for the line output. Too small output capacitors cause audible bass roll-off, for example 100 uF combined with a 100 ohms load attenuates 16 Hz by 3 dB. If you actually used a line input to drive headphones, then it is obviously much worse, and the line output also might not be able to supply enough current to drive the headphones at a sufficiently high level without audible distortion.

 

[RRod]

   
You mean comparing to the weak amp in my laptop?

 
I'm assuming you know that amplification is not just about loudness. For example, you can get plenty of loudness for the HiFiMAN HE-6 from a weak amp, but the sound quality will be comparatively awful without something much more powerful.
 
Anyway, don't ask me. I'm not a tech guy. Lots of people talk about how a more powerful amp delivers more powerful bass with some headphones. Go ask them for the details. But when you hear much less bass even when cranking the volume to uncomfortable levels, you know there is a difference.
 
@cel4145
Perhaps you could offer insights here?

 
The HE-6 has an efficiency of ~84dB/mW; how loud exactly are you going to drive those with a weak amp?

 

[cel4145]

The HE-6 has an efficiency of ~84dB/mW; how loud exactly are you going to drive those with a weak amp?

Good point. I don't think I've ever heard anyone say that they work well with a "weak amp." :etysmile:

 

[Music Alchemist]

  Everything has stronger bass at higher loudness. Did you level match the amplifiers ?
 
Other than that, it is actually quite possible for onboard headphone outputs to have audible issues with bass response, and it is not because of lack of power. They often have rather high output impedance (the Realtek datasheets recommend up to 75 ohms external resistors for some codec chips), although that is more likely to increase bass levels with full size headphones, at the expense of somewhat increased distortion. The outputs are also frequently capacitor coupled, with the datasheets suggesting 100 uF capacitors for the headphone jack, and 4.7-10 uF for the line output. Too small output capacitors cause audible bass roll-off, for example 100 uF combined with a 100 ohms load attenuates 16 Hz by 3 dB. If you actually used a line input to drive headphones, then it is obviously much worse, and the line output also might not be able to supply enough current to drive the headphones at a sufficiently high level without audible distortion.

 
Read what I said before. Even at higher than comfortable volume levels from the computer (which can only be done on some songs), the bass was noticeably weaker than with the amp at much lower volume levels, and all other volume levels as well. When it's that obvious, controlled testing is unnecessary unless I'm trying to prove something.
 

  The HE-6 has an efficiency of ~84dB/mW; how loud exactly are you going to drive those with a weak amp?

 
You're missing the point. You need a very strong amp to get the best sound out of them, and even an amp that is just powerful enough to get a lot of volume won't get the best sound.

 

[RRod]

   
Read what I said before. Even at higher than comfortable volume levels from the computer (which can only be done on some songs), the bass was noticeably weaker than with the amp at much lower volume levels, and all other volume levels as well. When it's that obvious, controlled testing is unnecessary unless I'm trying to prove something.
 
 
You're missing the point. You need a very strong amp to get the best sound out of them, and even an amp that is just powerful enough to get a lot of volume won't get the best sound.

 
I'm not debating the fact that some cans need an amp, or that some amps are just too weak for some headphones. But you seem to be supporting the assertion---all too common around here---that upgrading an already strong-enough amp does magik things to the headphone's sound. Like how the HD800 is supposed to "open-up" suddenly if I bought a Ragnarok instead of my Magni.
 
But none of this matters as your Stax is obviously going to sneeze at anything other than an amp made for the task.

 

[Music Alchemist]

  I'm not debating the fact that some cans need an amp, or that some amps are just too weak for some headphones. But you seem to be supporting the assertion---all too common around here---that upgrading an already strong-enough amp does magik things to the headphone's sound. Like how the HD800 is supposed to "open-up" suddenly if I bought a Ragnarok instead of my Magni.
 
But none of this matters as your Stax is obviously going to sneeze at anything other than an amp made for the task.

 
I am saying that an amp strong enough to attain sufficient volume is not necessarily strong enough to attain the best sound. I used the HE-6 as an example because it is well known that it requires more than just an amp that can give it enough volume.
 
True, but I'm also getting the JVC HA-SZ2000, maybe even first, since I already have the money for it. Despite having high sensitivity and being just 16 ohms, virtually every owner insists that it absolutely requires an amp to get the best sound. (But most people use it for heavy bass with EQ, so that's different than normal listening. Plus it has two drivers on each side.)