Why am I supposed to be worried about power?

I have Audio Technica ATH-AD700's. Sometimes I struggle with getting the volume low enough, not the other way around. I keep reading people's suggestions to make sure there is enough power to drive a set of headphones and I keep thinking these people must be on the fast track to deafness. I like the idea of getting a nice DAC and Amp over using on-board sound but I cannot figure out why I would want to add another step to the sound delivery process.

well it all has to do with the headphones your using. the ones you describe have a Impedance of 32 Ohms... that is low and they're easy to drive. 650s have 300 ohms and others like the Hi fi man headphones can be super power hungry, needing lots of power to drive.


but an amp brings other benefits as well, so your headphones might be easy to drive but they have potential to sound better with an amp. Clarity was improved greatly when I bought an amp, even when my headphones didn't need the power.


edit: I should also add that my dac significantly improved my sound quality as well especially for music.

thats why you see a lot of people suggestion the magni+modi combo because its 100$ each and its way better than a sound card.

also if you're putting your headphones into the headphone slot on the soundcard its amplified too so that could be why you get decent volumes.. but I did the same before I had 650s with 558s and it was not close to the standalone amp

More power often results in less distortion and better quality sound, regardless of the price, type, or brand of equipment being used.

If you don't listen loudly, you don't need to worry about power even slightly. People put way too much emphasis on it and the simple explanation for that is that they are just wrong.

With DAC + Amp won't you lose some sound effects processing? I don't remember the specific features but I remember Sound Blaster promoting extra sounds with their hardware and such.

dandragonrage said:

If you don't listen loudly, you don't need to worry about power even slightly. People put way too much emphasis on it and the simple explanation for that is that they are just wrong.

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Not really. an Amp definitely provides significant clarity and sound quality difference from soundcards or motherboard sounds. Distortion will exist without.

Corvette said:

With DAC + Amp won't you lose some sound effects processing? I don't remember the specific features but I remember Sound Blaster promoting extra sounds with their hardware and such.

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Yes, thats why some prefer not to use a usb dac and amp combo there is no "virtual" surround for gaming etc.

but in my experience that doesnt matter very much

Phlorge said:

the ones you describe have a Impedance of 32 Ohms... that is low and they're easy to drive.

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It's important to understand the relationship between impedance and a headphone being easy to drive. Lower impedance does NOT automatically mean a set of headphones will be easier to drive.

The goal being watts, low impedance headphones primarily require current (amps), while high impedance headphones primarily require Voltage. Low impedance headphones are "easy" to drive, at least when it comes to portable sources, because portable sources run from batteries and thus are dealing with relatively low/limited voltage. "low voltage" (<20v) batteries can still produce plenty of current however.

But the thing is, not everyone is some douche listening to shit headphones on their chinaphone. When you're actually using real equipment to drive your headphones, stuff that isn't operating from batteries, it can be easy to find cases where higher impedance headphones are actually easier to drive, and low impedance headphones are not only not easy to drive, but if your gear can't deliver enough current they will clip and sound like crap.

The best thing you can do for yourself is match your headphones to your gear. I would personally try to avoid headphones under ~120ohms unless you know you will never be current limited, and same with headphones over ~300ohms unless you know that your sources can deliver a lot of voltage.

The main problem comes from lack of knowledge.

Power is the combination of voltage AND amperage. Just because an amp outputs 10W doesn't mean that your headphones are properly amped: they might need more volts and more amps, and the amp might not be able to supply them.

Anyway, if you have the required voltage and amperage for the cans you are using... buying a more powerful amp will get NO DIRECT GAINS...

At the end of the day, an amp is a wire with gain, nothing else.

Phlorge said:

Not really. an Amp definitely provides significant clarity and sound quality difference from soundcards or motherboard sounds. Distortion will exist without.

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If you are running your amp at a high enough volume to get significant distortion, an amp will help, which I didn't dispute to begin with.

If you're saying the difference between, say, 0.05% and 0.01% and 0.005% distortion are noticeable, you are incorrect, period. Speakers - especially those which have severe restrictions in form factor and volume (e.g. headphones) - distort a hell of a lot more than any amp when used properly.

Also, adding extra pieces of equipment (and the wires to connect them together) into the chain itself increases distortion.

Amps are sometimes useful, but usually only when you're looking to get relatively loud outputs.

A lot of people on this site (and much worse, head-fi) just recommend amps and high-end DACs universally without considering the usage. Doing so is wrong, and people shouldn't try to spend someone's money like that. People come here asking for advice and should not be misled into buying things they don't need and won't benefit from just because the question happened to be answered by people who either don't know better or don't care (it's not their money, after all!).


It is indeed true that depending on the impedance of the speaker (headphones in this case), the power will be delivered in whatever combination of voltage and current (lower impedance speakers demand more power through current; higher impedance more through voltage), but for someone who specifically says they don't want to listen loud, it's rarely going to be an issue. He would need some TERRIBLE amplification or phones with a really weird impedance for this to be a problem.

^ Yup. My Denon D2000's are only 25 Ohms, so are considered 'easy' to drive. But I can tell you that with a proper amp the dynamic range (especially the 'power' in the bass) is significantly improved.

The Travagans Red amp matched my Denons perfectly - the pairing is fantastic. I've tried a number of other amps and none sound quite as good so far, and some far worse (Shiit Magni and O2 are a pretty bad match, although on paper it should sound amazing....)

Corvette said:

With DAC + Amp won't you lose some sound effects processing? I don't remember the specific features but I remember Sound Blaster promoting extra sounds with their hardware and such.

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The problem here is that people have gotten very ambiguous in a very lazy way when it comes to what the term "DAC" actually means.

In it's simplest form, it's simply the chip that performs the digital to analog conversion, nothing more. It is not a "replacement" for a soundcard, but rather a chip that is found on every soundcard. The term "DAC" has also come to be used to describe what are essentially external soundcards however, that connect to the PC via a USB interface. This is where things can get confusing.

A "DAC" in the traditional sense does not have to replace an internal soundcard. You can simply use the digital output from the soundcard instead of the analog output, at which point it will still be using the soundcard for all it's internal effects processing, but not it's DAC. The digital sound will then travel to the DAC, where the digital to analog conversion takes place.

But of course, if you are talking about a USB DAC, then it WILL replace your soundcard, as again, a USB DAC would more appropriately be described simply as a USB soundcard.

strend said:

^ Yup. My Denon D2000's are only 25 Ohms, so are considered 'easy' to drive. But I can tell you that with a proper amp the dynamic range (especially the 'power' in the bass) is significantly improved.)

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Bass is power, essentially. The vast majority of the power in your audio signal is concentrated in the bass region. See the first chart here. On average, about 60% of your power is at 500Hz and below. About 50% is in 350Hz in below. By contrast, only about 12% is in 4kHz and above (the upper bound normally described is 20kHz, though some sources of audio do have a small amount of content above this, and some humans can hear a bit above 20kHz as well). This is also reflected in driver excursion - bass requires a lot more excursion than treble, everything else held constant (especially true for full-range speakers used in headphones)

That's why bass is usually where you can hear the distortion.

But again, the benefits of an amplifier start to come out as you increase the volume. Almost any amplifier can handle almost and headphones at low volumes with reasonably low distortion.

By the way, it's not a case of the lower the impedance, the easier to drive. It has to be balanced. Too low and they demand more current than some amplifiers can handle (25 ohms is actually sub-optimally low for many headphone amplifiers). Too high and they demand more voltage than some amplifiers can handle. These effects are still dependent on the volume you're looking to get out of them, though.

GotNoRice said:

The problem here is that people have gotten very ambiguous in a very lazy way when it comes to what the term "DAC" actually means.

In it's simplest form, it's simply the chip that performs the digital to analog conversion, nothing more. It is not a "replacement" for a soundcard, but rather a chip that is found on every soundcard. The term "DAC" has also come to be used to describe what are essentially external soundcards however, that connect to the PC via a USB interface. This is where things can get confusing.

A "DAC" in the traditional sense does not have to replace an internal soundcard. You can simply use the digital output from the soundcard instead of the analog output, at which point it will still be using the soundcard for all it's internal effects processing, but not it's DAC. The digital sound will then travel to the DAC, where the digital to analog conversion takes place.

But of course, if you are talking about a USB DAC, then it WILL replace your soundcard, as again, a USB DAC would more appropriately be described simply as a USB soundcard.

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its important to note that there is a distinction between the two chips, soundcards do have a dac and so does my iphone.. but the standalone dac is considerably better at its job.

Power isn't necessarily about being louder, it's about better sound quality. It doesnt take a lot of power to reproduce high squealing frequencies at a high level and even low powered systems can damage your hearing but the smaller, more intricate details do need more oomph. Something like Diana Krall's breaths in between notes or the realistic pluck of a guitar string needs a proper amount of power to be reproduced realistically and with dynamics. Maybe for video games with nothing but explosions and high pitched sound effects there are much fewer intricate details and extra power isn't required but for the best SQ and realism in music, the more power you have (to a point) the better.

Phlorge said:

its important to note that there is a distinction between the two chips, soundcards do have a dac and so does my iphone.. but the standalone dac is considerably better at its job.

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An external DAC benefits from not being inside a computer case with lots of electrical noise and interference but that is where the advantages end. There are examples of soundcards and external DACs that use the same actual DAC chips, and aside from the interference potential, no, there is nothing about the chip in the external enclosure that makes it "considerably better at its job".

GotNoRice said:

It's important to understand the relationship between impedance and a headphone being easy to drive. Lower impedance does NOT automatically mean a set of headphones will be easier to drive.

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I was going to say

yeah, in fact as a generalization lower power sources and sinks are usually high impedance

GotNoRice said:

An external DAC benefits from not being inside a computer case with lots of electrical noise and interference but that is where the advantages end. There are examples of soundcards and external DACs that use the same actual DAC chips, and aside from the interference potential, no, there is nothing about the chip in the external enclosure that makes it "considerably better at its job".

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I guess it just depends on the headphones and the persons setup? Because I noticed a big difference when I got my M&M combo for my 558s and 650s.

Was using a soundblaster Z before

MacLeod said:

the smaller, more intricate details do need more oomph. Something like Diana Krall's breaths in between notes or the realistic pluck of a guitar string needs a proper amount of power to be reproduced realistically and with dynamics.

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That's incorrect. That's actually a function of the speaker itself, such as the motor strength (BL) and the properties of the cone (stiffness, resonant frequencies/ringing, etc.)

Damping factor is generally the least important spec.

The only reason that a higher-power amplifier might have higher sound quality is that it might have lower distortion at the volume you listen at. But it would take a very bad amplifier or running an amplifier beyond its intended power level (or below its rated impedance - which does happen with some speakers considering impedance of the speaker actually varies over the frequency range - so some specific speakers do present a challenge to some amplifiers - and this too doesn't much matter at low volumes) to make it a noticeable difference. Again, you aren't going to notice fractions of a percent THD when your speakers are distorting a thousand times as much.

Phlorge said:

I guess it just depends on the headphones and the persons setup? Because I noticed a big difference when I got my M&M combo for my 558s and 650s.

Was using a soundblaster Z before

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The problem is that you're still talking about soundcards and external DACs like they are abstract concepts, when really, it comes down to what they have inside. All I'm saying is that no, it's not a given that an external DAC will automatically be better than a soundcard in terms of it's analog output. It has potential advantages, which may or may not ultimately come into play, but it really comes down to the chips used and their implementation. My X-Fi Titanium HD for example, has an internal DAC that is better than quite a few external DACs out there. Your Soundblaster Z is/was the bottom-of-the-line offering in the Z series, with a DAC that is absolutely nothing special. If you were talking about the top-end ZxR, which has a DAC equivalent to the X-Fi Titanium HD, it certainly could have resulted in a different outcome.

GotNoRice said:

The problem is that you're still talking about soundcards and external DACs like they are abstract concepts, when really, it comes down to what they have inside. All I'm saying is that no, it's not a given that an external DAC will automatically be better than a soundcard in terms of it's analog output. It has potential advantages, which may or may not ultimately come into play, but it really comes down to the chips used and their implementation. My X-Fi Titanium HD for example, has an internal DAC that is better than quite a few external DACs out there. Your Soundblaster Z is/was the bottom-of-the-line offering in the Z series, with a DAC that is absolutely nothing special. If you were talking about the top-end ZxR, which has a DAC equivalent to the X-Fi Titanium HD, it certainly could have resulted in a different outcome.

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Even though you have a higher quality DAC wouldn't you notice distortion from inside your system still ? Or does it prevent this from being an issue>?

Phlorge said:

Even though you have a higher quality DAC wouldn't you notice distortion from inside your system still ? Or does it prevent this from being an issue>?

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It depends. In my specific case, if I have it in the 1x slot that is up near my videocards, near my processor, and near the VRMs on my motherboard, I do get interference. If I have the card in the 4x slot at the bottom though, which is mostly away from everything else, I get none. That is where I have it now.

dandragonrage said:

That's incorrect. That's actually a function of the speaker itself, such as the motor strength (BL) and the properties of the cone (stiffness, resonant frequencies/ringing, etc.)

Damping factor is generally the least important spec.

The only reason that a higher-power amplifier might have higher sound quality is that it might have lower distortion at the volume you listen at. But it would take a very bad amplifier or running an amplifier beyond its intended power level (or below its rated impedance - which does happen with some speakers considering impedance of the speaker actually varies over the frequency range - so some specific speakers do present a challenge to some amplifiers - and this too doesn't much matter at low volumes) to make it a noticeable difference. Again, you aren't going to notice fractions of a percent THD when your speakers are distorting a thousand times as much.

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We might be talking about 2 different things. Im not saying that amp power is what brings out detail in music. Youre absolutely right in that is the speaker's job. Im also not referring to typical recordings of music like rock where all the levels are pegged out at max and there really isnt any difference in level from a vocal to a snare drum hit to a guitar note. Im talking about quality recordings where the high impact parts are mixed at higher volumes and the lower impact are at lower volumes. In these types of recordings those smaller details and parts are at a much lower level and so youll need to turn the volume up in order to get the realism and impact from them.

This is a video showing kinda what Im talking about.

http://youtu.be/3Gmex_4hreQ

In that recording, if it were mixed all maxed out then all that extra power wouldnt come in handy because a small amp would be enough to get the guitars and other high frequencies up as loud as you could stand. But if it were the quality recording then you could turn the volume up much higher and the snare would have much more impact but not be deafening and the guitar notes would be more discernible and distinct as would other smaller details.

Youre right that the speaker is what is most responsible for bringing the details out but Im talking about the impact and dynamics from those smaller, lower volume details. For that youll need more power. Now Im not saying you need 500 watts per channel, but you want a hefty amount. Now if youre listening to nothing but Korn or Disturbed (which I do a lot) then not so much. You listen to Alison Krauss or Rebecca Pidgeon or Livingston Taylor or Keb Moe or anything in that genre of high quality, detail rich recording and youll really put that extra power to use.