Calculating Audeze LCD 2's Power Requirement vs O2

[BoredErica]

Looking for a super TL;DR guide to how to calculate power requirements? It's in here:

Step 1) Find either the sensitivity of your headphone (measured in dB/Vrms) OR the efficiency (measured in dB/mw). Google it.

Step 2) Find out the rated impedance of the headphone. They are measured in Ohms.

 

Step 3a) If you have the sensitivity: Go to http://www.jensign.com/S4/calc.html Enter the impedance, enter the sensitivity in the box, and click "Get Efficiency". Now you have efficiency. Now, go to step 3b.

Step 3b) If you have the efficiency: Take this formula and plug numbers in: 10^((dB peak-efficiency)/10). dB peak is the max volume you want to listen at (be careful of hearing loss, which starts at 85dB and up). Efficiency could be, say, 98 dB/mw. So: 10^((105-98)/10). It takes that much power in mw to get the headphone to 105 dB.

 

Step 4) Now you know how much power you need. Figure out how much power your amp can deliver. Find the amount of power an amp is rated to be able to output at the impedance of your headphone. So if it says at 300ohms: 500mw, your headphone calculation better be under 500mw if it's 300ohms. More often, the impedance of your headphone won't match the specs, because your impedance might be like... 75. Unless you want to read the long version of this guide (the parts outside of the spoiler), you better just estimate. If your amp manufacturer doesn't list any max output specs or only lists it for one impedance and it isn't close to the impedance of your headphone, you're most likely screwed.

 

DISCLAIMER DISCLAIMER DISCLAIMER: The above guide is oversimplified, and assumes your amp's specs are honest, accurate, and specified at an impedance close to what you need. It also ignores fringe cases. (This guide works perfectly if you are getting the Objective2 amp because all specs are listed perfectly.) Don't come crying to me if you can't find amp specs on your motherboard (you won't, trust me), or your tube amp won't work as advertised (because those are fringe cases).

 

Calculating Power Requirement of LCD-2

A few of you were doubtful about the O2's ability to drive LCD 2. Here is my answer.

 

Sensitivity is dB/Vrms

Efficiency is dB/mw

 

To convert between the two, we need to know the impedance of a headphone. There is a formula for it, but just use this calculator (I've verified that it's super legit).

http://www.jensign.com/bdp95/headphones/

 

LCD2, being a planar magnetic headphone, the impedance is pretty much the same no matter the frequency.

As I mentioned in the past on another thread, Audeze's website lists the efficiency of LCD2 but calls it sensitivity.

 

To get voltage requirement: 

10^((dB peak-sensitivity)/20) 

 

To get power requirement: 

10^((dB peak-efficiency)/10)

 

LCD2's impedance and efficiency has been different in the past. The best good data I can find which shows an old LCD2 revision is from Inner Fidelity's measurements here, from 2012: http://www.innerfidelity.com/images/AudezeLCD2sn53211704circa2012.pdf

Unfortunately, Inner Fidelity's measurements are listed differently than the format I use. It needs to be converted. 2012 LCD2 requires 0.209 Vrms to reach 90dBSPL according to their chart.

90 + 20 * LOG ( 1/0.209 ) = 103.6 dB/Vrms, & @ 59 Ω = 91.3 dB/mw. The efficiency of 2012 LCD2 is 91.3 dB/mw. The impedance and sensitivity are from Tyll's measurements (which BTW, seems very accurate, props to the man. His measurements were dead on for HD800).

 

Now let's figure out the efficiency of LCD2 with Fazor from Tyll's latest measurements as listed here: http://www.innerfidelity.com/images/AudezeLCD2sn5423021Fazer.pdf

LCD2 w/ Fazor requires 0.114 Vrms to reach 90dB SPL.

90 + 20 * LOG ( 1 / 0.114 ) = 108.86 dB/Vrms, & @ 72 Ω = 97.4 dB/mw.

 

Let us compute the required amount of power for a headphone now we know the impedance and the efficiency. Don't forget the formulas to figure out power and voltage requirements which I already listed.

 

2012 LCD2 based on IF (91.3 dB/mw, 103.6 dB/Vrms):
105dB:

23.4mw

1.17v

 

110dB:

74.1mw

2.1v

 

115dB:

234.4mw

3.72v

 

120dB:
741.3mw

6.6v

 

Latest LCD2 based on Audeze's spec sheet (93 dB/mw, 104 dB/Vrms):
105dB:
15.8mw

1.1v

 

110dB:
50.1mw

1.89v

 

115dB:
159.5mw

3.35v

 

120dB:
501.2mw

5.6v

 

Latest LCD2 based on IF (97.4 dB/mw, 108.8 dB/Vrms):
105dB:
5.75mw

0.65v

 

110dB:
18.2mw

1.15v

 

115dB:
57.5mw

2.04v

 

120dB:
182mw

3.63v

 

Looking at O2's Capabilities

O2's max output (from NWavguy's blog):

Max Output (33 Ω)   613 mW 

Max Output (150 Ω) 355 mW 

Max Output (600 Ω) 88 mW

 

P (Power in w) = V (Voltage RMS) * I (Current in amps)

I = V / R   (Ohm's Law)

Therefore: 

P = V * (V / R)

Therefore:

P = (V^2) / R

 

0.613 = (V^2)/33Ω

V = 4.5  ; Therefore, we know that the O2 can power 4.5V 

Since P = V * I...  0.613 w = 4.5 x I  

I = 0.14 amps.

​If you do this calculation for all impedances:

15Ω,   337 mW - V = 2.2, I = 0.15

33Ω ,  613 mW - V = 4.5, I = 0.14

150Ω, 355 mW - V = 7.3, I = 0.048
600Ω, 88  mW -  V = 7.3, I = 0.012

 

Voltage swing is simply how much voltage a headphone can put out from one situation to the next. The O2 can dish out 7.3v for most situations.

As you can tell by matching the specs of the O2 with my calculations, the O2 can drive all three possible LCD-2s to 120 dB SPL. Well, except maybe the 2012LCD2. That really depends on how many volts the O2 can dish out at 59Ω, which isn't specified by Nwavguy. Either way though, it can power it to above 115dB. If we assume the O2 can deliver 7.13v still, we get something like this:

P = (7.13^2)/59 = ~903mw. (The highest peak wattage O2 can output out of all possible impedance is at 49Ω.)

 

...Which means, the O2 would easily be able to power it. It's important to note that for the purposes of this particular headphone and calculation, we're arguing between 1-2 dB here... something like 118dB vs 120dB. Every extra dB requires that much more effort to achieve.

 

 

How Loud is Too Loud?

The threshold of pain is at 130dB. Hearing loss begins at 85dB which sets in after 8 hours of continuous music. Refer to this chart below:

120dB is such an insane number, IT'S NOT EVEN LISTED IN THE CHART! At 120dB you will suffer hearing loss in approximately 10 seconds. What use is an audiophile with busted ears? Imagine rocking out to 120 dB for an hour a week. Imagine what that does to your hearing.

 

The hardest track to power is a special type of non-compressed music which has consistently quiet sounds with sudden, brief loud sounds (Sforzando notes). This is very different from a normal orchestrated piece, with sustained high levels, and even more different from modern, heavily compressed pop music. Nwavguy gives this guideline to tell us how much dB peaks we can expect from a type of track:

• Highly Compressed Pop: –6 dB to –9 dB
• Well Recorded Pop: –9 dB to –12 dB
• Well Recorded Acoustic/Jazz: –12 dB to –18 dB
• Wide Dynamic Range Classical: –18 dB to –30 dB

Let's assume the worst case scenario given by Nwavguy with the ridiculous 30dB peak. 85 dB + 30dB peak takes us to 115dB with an extra 5dB of "buffer" (aka overkill). Do you want to pick how much hearing loss you want? Now is your chance!

 

A few of you voiced concerns that going close to or even halfway of the maximum output power of an amp drives up distortion. Nwavguy himself has disproved this (well, for the O2 anyways):

Here we can see that distortion increases very little until you hit a certain point, where the distortion explodes. This is basically clipping point. This shows that we do not need an extra "buffer" on top of the 5db buffer for the 115db buffer assuming you listen to the most audiophile and hard to drive tracks and another buffer given that 115db itself will cause hearing damage in a few minutes. Worried that the chart is misleading because it lists voltage? P = (V^2) / R. Let's say the first clipping line shown in the picture is at uhm... 2.2v? That's P = (2.2^2)/15 or 322 mw. Do you remember NWavguy's listed maximum output power at 15 Ω? It's 337 mW. I was very close to guessing the maximum output of O2 at 15Ω simply by eyeballing the graph. It also proves that the large distortion jump occurs during clipping, not at some random amount before clipping. How much distortion are we trying to keep under in total? Under 0.005%. But because music itself masks distortion, the generally accept number is 0.01%. As you can tell from the graph by NWavguy, you won't even hit 0.005% (as long as you don't clip). From a human perception standpoint, we're not going to be able to distinguish small amounts of distortion anyways when the music is blasting 120dB SPL to our ears, even if the distortion was much higher. (Me, I'd be grasping my ears for relief.)

 

Miscellaneous Information

Let's do a less insane situation on how much power you will need. Say you listen at 85 dB with 15 dB peaks (still in audiophile jazz category, far beyond compressed Lady Gaga). That is 100 dB. Let say you're using the most inefficient version of LCD 2, with an efficiency of 91.3 dB/mw. That's 10^((100-91.3)/10) or 7.4mw of power required. Do you understand just how much buffering and insanity we've gone through to try to see if the O2 can hold up to push requirements up x100 the 100dB listening volume implies with the least efficient headphone out of the three? The Audeze's website recommendation for LCD 2 ranges from 1-4w.

 

To calculate maximum SPL from a given amount of power we use this formula:

Efficiency in dB/mW + 10 * LOG ( Pmax in mW)

91.3 + 10*Log(4000) = 127.32 dB, which should cause hearing damage in approximately 1.875 seconds.

 

Some audiophiles want tube amps for some reason, and that makes their life harder because tube amps have inferior amounts of distortion as power output goes up. They also have higher output impedance, and when that is too high in relation to the impedance of the headphone (this can easily happen with low impedance headphones like LCD2 or LCDX), that causes some fuckery with the amp's ability to output power. Such high output impedance also distorts the sound (but people get tube amps to get those distortions in sound because they find it euphonic). So: Tube amps will make your life harder, especially if you want to calculate the amount of power the amp actually needs to give out. If you're looking for a simple, cheap, powerful, and dead-on accurate amp, a solid state amp like O2 can drive the LCD 2 without any problems. If you're using a tube with very high output impedance, I can see why Audeze's 1-4W power rating actually makes sense. But it doesn't make sense to people using the O2.

 

Impedance Swings

Planar magnetic (aka "Orthodynamic") headphones like the LCD-2 have the same impedance across all frequencies, so the argument that impedance changes with frequency played doesn't even apply here even if it was a valid argument.

 

 

In a dynamic headphone this isn't the case. The higher the impedance a headphone is at a frequency, the easier it is to power at that frequency. To figure out the worst case scenario we need to look at a dynamic headphone at its lowest impedance. The frequency in which the impedance of a headphone is at its maximum is called the 'resonant frequency', which is where the headphone is easiest to drive. Thankfully, like every dynamic headphone and their mom are easier to power than the 2012 LCD2.

 

P = (V^2) / R

P is power in watts (not milliwatts). V is voltage. R is impedance of the headphone. The larger R is, the smaller P is. It's simple math. (I talk about the voltage changing in the next section.) If we look at the impedance rated for a headphone vs measured impedance, the rated impedance by the manufacturer tends to be the lowest impedance for a headphone at all audible frequencies (in other words, shows you the worst case scenario). HD800 has lowest impedance of about 330ish but Sennheiser rounds it down to 300 just to be safe. This is why companies call it "nominal impedance". The listed specs are already pretty much worst case scenario from the get-go.

 

Sensitivity Ratings @ 1khz... A problem?

So, I've already shown why a higher impedance by itself actually makes a load easier to drive. But that's assuming that voltage required stays constant. (Hint: It does.) Sensitivity ratings are typically taken at 1khz. Sensitivity is measured in dB/Vrms. It's not as complicated as it looks: You give the headphone 1Vrms and watch how loud it gets for a given frequency. Why 1khz? Why don't we measure for other frequencies? If we took a sensitivity reading for every frequency from 20hz to 20khz, took the data, plotted it on a graph, and connected the dots, we would actually be making a frequency response graph. That's the key: We are trying to pick a spot on the frequency response that represents the "average volume". And so, many industry leaders choose 1khz. (Please go complain to Sennheiser, for example.)

No, you can't look at the quietest parts of the frequency response graph and say they are "the hardest to drive". The DT990 has a trough of -15dB and a peak of +5dB. When the DT990 plays 120dB at its -15dB trough (13khz), it will play 100hz notes 20dB louder (120+20 = 140dB). You're not buffering for anything by trying to strive for 120dB at 13khz. Given the same amount of voltage, a headphone is not going to play as loudly at every frequency, yes, but that's called a frequency response. DT990's sound signature is more V shaped. That's a characteristic of the headphone, not the amp. If your amp is changing the frequency response of your headphone, it's not transparent.

 

You want to pick a frequency that represents the average loudness of a headphone, not its peaks or troughs. Many headphones screw with things outside of 1khz. Note how in the graph, I picked four different headphones from four different companies, yet they all have non-screwy frequency response at 1khz. The Grado PS1000 has stupid amounts of treble. The old Beats might have ridiculously loud bass. Some headphones are V shaped in their frequency response. 1khz is a fine point to pick as far as points go. If your headphone happens to be ridiculously hard to drive AND have a big 1khz peak in its frequency response according to a frequency response graph, you might worry. But if you actually have a high quality headphone with a frequency response that's remotely flat, you should be just fine.

 

So when we look at the equation, P = (V^2)/R, we now know a lower R increases the amount of power required, and the voltage variation required to get a given loudness is only useful if we pick one reading that represents the average loudness of a headphone across its entire frequency response. I've just accounted for every single variable in the power equation.

 

 

 

TL;DR:

O2 can power LCD 2.

Quit complaining and enjoy the music.

[helping]

tl;dr

 

nice pictures

[ShearMe]

[TheGrapeEscape]

Bah, the easiest way to see if the O2 can power the LCD2 is to plug it straight in and listen (no math needed). Take this review for instance http://linustechtips.com/main/topic/167954-audeze-lcd-2-review/

 

I used the same method to find out if a Galaxy S3 can power HE400 headphones (spoiler: it can).

 

All this talk about whether something can power something else is purely academic. Best just test that sort of thing by doing it or finding someone else who has.

 

dontknowwhythisisevenanissue.jpg

[BoredErica]

Bah, the easiest way to see if the O2 can power the LCD2 is to plug it straight in and listen (no math needed). Take this review for instance http://linustechtips.com/main/topic/167954-audeze-lcd-2-review/

 

I used the same method to find out if a Galaxy S3 can power HE400 headphones (spoiler: it can).

 

All this talk about whether something can power something else is purely academic. Best just test that sort of thing by doing it or finding someone else who has.

 

dontknowwhythisisevenanissue.jpg

You'll find a ton of audiophiles who claim various things, many of which will say that an amp needs to have more power than is needed to produce good sound instead of just loud sound, etc. It's interesting that you brought up Lays' review. Lays was one of the people who brought up the idea that an amp might need extra power to prevent distortion, and that he felt his O2 might not be enough. Reviews are subjective. Math is not. A person will always let expectation bias and placebo affect their perception no matter who the person is. Lays is not magically immune. One might assume that hearing distortion is a black and white affair but it is not. There is no need to bring up the possibility of O2 not being enough if Lays was perfectly objective in his attempts at reviewing the distortion of LCD2 with O2 because he didn't hear any. Yet he pointed out all these possibilities, and later on switched from the O2 onto tube amps and proceeded to list some impossible benefits when doing so. 

 

My point is that reviews have limits. Not everything can be objectively measured. But when they can, I prefer to take that path. There is no 'what if'. There is no 'maybe I just didn't know what I was looking for so I don't know what I'm missing out on by not getting a stronger amp'. This is the type of thinking that looks batshit crazy from a distance when you're not in Headfi, which some people end up falling into themselves, slowly. And then you try a new amp in a sighted test and then you could swear it sounds better. Had somebody else claimed this, you would've brushed them off as being coo-coo. But now you are the one experiencing it, and it feels valid because you hear it. Hey, I was just trying to be open-minded by testing stronger amps! I wasn't expecting a difference but that's what I heard! You ignore the fallacies of human perception. And boom. Now you want more than you actually need.

 

Also, I find it more interesting and more educational go the math route.

[NannerBeans]

People just want a reason to justify spending $1000 on an amp. 

[TheGrapeEscape]

You'll find a ton of audiophiles who claim various things, many of which will say that an amp needs to have more power than is needed to produce good sound instead of just loud sound, etc. It's interesting that you brought up Lays' review. Lays was one of the people who brought up the idea that an amp might need extra power to prevent distortion, and that he felt his O2 might not be enough. Reviews are subjective. Math is not. A person will always let expectation bias and placebo affect their perception no matter who the person is. Lays is not magically immune. One might assume that hearing distortion is a black and white affair but it is not. There is no need to bring up the possibility of O2 not being enough if Lays was perfectly objective in his attempts at reviewing the distortion of LCD2 with O2 because he didn't hear any. Yet he pointed out all these possibilities, and later on switched from the O2 onto tube amps and proceeded to list some impossible benefits when doing so. 

 

My point is that reviews have limits. Not everything can be objectively measured. But when they can, I prefer to take that path. There is no 'what if'. There is no 'maybe I just didn't know what I was looking for so I don't know what I'm missing out on by not getting a stronger amp'. This is the type of thinking that looks batshit crazy from a distance when you're not in Headfi, which some people end up falling into themselves, slowly. And then you try a new amp in a sighted test and then you could swear it sounds better. Had somebody else claimed this, you would've brushed them off as being coo-coo. But now you are the one experiencing it, and it feels valid because you hear it. Hey, I was just trying to be open-minded by testing stronger amps! I wasn't expecting a difference but that's what I heard! You ignore the fallacies of human perception. And boom. Now you want more than you actually need.

 

Also, I find it more interesting and more educational go the math route.

 

I wasn't really dissing the math. Hell, I've done enough of it trying to figure if A will work with B. I'm just saying that I've seen enough "audiophile" talk about what you can and can't do that it's just easier to test out a hypothesis by doing it. I recognise most measurements for audio equipment tends to be bunk, because who is going to check that, and even when it's checked who is going to care, if it subjectively sounds better (or worse)? And of course there are a lot of people who will talk out their arse when it comes to audio equipment.

 

Anyhoo, I'm just saying the "just do it" method tends to provide more definite resolutions to the question "will A work with B" because you're testing it. Someone can ignore the subjective or objective opinion and instead go with a personal one.

[h264]

You'll find a ton of audiophiles who claim various things, many of which will say that an amp needs to have more power than is needed to produce good sound instead of just loud sound, etc. It's interesting that you brought up Lays' review. Lays was one of the people who brought up the idea that an amp might need extra power to prevent distortion, and that he felt his O2 might not be enough. Reviews are subjective. Math is not. A person will always let expectation bias and placebo affect their perception no matter who the person is. Lays is not magically immune. One might assume that hearing distortion is a black and white affair but it is not. There is no need to bring up the possibility of O2 not being enough if Lays was perfectly objective in his attempts at reviewing the distortion of LCD2 with O2 because he didn't hear any. Yet he pointed out all these possibilities, and later on switched from the O2 onto tube amps and proceeded to list some impossible benefits when doing so.

My point is that reviews have limits. Not everything can be objectively measured. But when they can, I prefer to take that path. There is no 'what if'. There is no 'maybe I just didn't know what I was looking for so I don't know what I'm missing out on by not getting a stronger amp'. This is the type of thinking that looks batshit crazy from a distance when you're not in Headfi, which some people end up falling into themselves, slowly. And then you try a new amp in a sighted test and then you could swear it sounds better. Had somebody else claimed this, you would've brushed them off as being coo-coo. But now you are the one experiencing it, and it feels valid because you hear it. Hey, I was just trying to be open-minded by testing stronger amps! I wasn't expecting a difference but that's what I heard! You ignore the fallacies of human perception. And boom. Now you want more than you actually need.

Also, I find it more interesting and more educational go the math route.

I think the reason Audeze reccomends 1W is simply for less efficient designs like OTL tube amps. In that case distortion and noise can become an issue at higher volumes. Keep in mind most audiophiles are pretty deaf too. I know one with a giant speaker system ... and hearing aids.

If your headphones get loud enough, you're not missing much to begin with. Which is always my response as such.

[MayflowerElectronics]

Without getting into math (I don't have time to do that right now) the O2 has more than enough power to drive LCD-2's to ear bleeding levels.

[BoredErica]

I think the reason Audeze reccomends 1W is simply for less efficient designs like OTL tube amps. In that case distortion and noise can become an issue at higher volumes. Keep in mind most audiophiles are pretty deaf too. I know one with a giant speaker system ... and hearing aids.

If your headphones get loud enough, you're not missing much to begin with. Which is always my response as such.

Right, I didn't think about tube amps. Speaking of which, they tend to have higher output impedances, and some people might purposefully get one with high output impedance relative to their headphone's own impedance (on purpose or on accident, which isn't hard to do considering the low impedance of many planars)... that screws with power delivery too. So, I could see somebody needing 1w-2w if they are using some types of tube amps and listen at 120db.

[Lays]

Right, I didn't think about tube amps. Speaking of which, they tend to have higher output impedances, and some people might purposefully get one with high output impedance relative to their headphone's own impedance (on purpose or on accident, which isn't hard to do considering the low impedance of many planars)... that screws with power delivery too. So, I could see somebody needing 1w-2w if they are using some types of tube amps and listen at 120db.

 

 

It would make more since to over-estimate power needed than to under-estimate and have people get mad @ companies for their products not working properly.

 

And seeing as the recommendations people are giving now with new fazor model of 500mw-2watt it's not terribly out of bounds IMO.  (Especially since their reasoning is 120db peaks in certain music whilst listening at higher levels)

 

Seeing as you found a 120db peak would take 500mw, the 500mw-2watt recommendation isn't all that bad.  (2 watts is obviously a bit much, but 500-1watt isn't terrible for extreme cases @ very high volumes if the user so desires that)

 

in 99.9999999999% of all occurrences, the o2 is 100% fine, I'm fairly sure maybe my o2 had problems, mayflower also said that sources with low output volume with high gain can cause distortion, so that could of been another issue.

 

But I'll add on one more thing that I've found, just because one product is fine, doesn't mean that people won't want something more aesthetically pleasing / "higher end". Even if measurements are worse. Because for many "audiophiles" it's not about raw measurements and how close it is to "reference sound", it's about how THEY enjoy their setup + sound it gives them, rather than raw scientific data.  (Which I have no problem with,) seeing as everyone's preference is different, and 90% of these people enjoy their hobby, even if it happens that they're spending thousands of dollars on things.

 

 

 

I also have a question, do certain frequencies take more / less power to produce?  If the driver has to flex more to make a low note than a high note, surely it would take more current to move it more?

 

For instance, could a 1khz tone @ 120 db take 500mw to produce, yet a 30 hz 120db tone take 1watt to produce?

[BoredErica]

I don't discuss looks and aesthetics and swag factors in this thread because that's not measurable and only subjective. There's a difference between buying something because swag or it's cool and buying it because you think it will make things sound more accurate (or even better, because that can be tested). In fact, I bought my HD800s and my Objective just because I felt like it. I don't need to blind test onboard vs Objective because IDC. I also don't claim Objective makes my music sound better or worse. I like it,  I bought it. I'm happy with it. But as soon as I seriously start claiming my O2 sounds better, I need to be more skeptical and start blind testing things. (Even if there are electrical, scientific reasons why the O2 would sound better, that doesn't mean I can hear the difference with my own ears.)

 

Regarding you question about measuring at 1khz, that is a good question. Planar magnetic headphones have the same impedance across all frequencies, so that makes measuring and our lives much easier. It should be constant everywhere. In a dynamic headphone this isn't the case. The higher the impedance a headphone is at a frequency, the easier it is to power at that frequency. So, to figure out the worst case scenario, we need to look at a dynamic headphone at its lowest impedance. From what I can tell by sifting through various impedance graphs on Inner Fidelity, 1khz is one of the best spots to find one of the hardest to drive area of the headphone. It's consistently one of the hardest spots to drive and also, 1k is pretty audible to the human ear. I checked HD800, HD600, AKG q701, DT 770 600ohm, Grado ps1000, Shure 1540, Ad700x, M50x. Some headphones have slightly lower impedances at 10hz... but first of all, the difference is small, and second, I can't even hear 10hz, let alone the quality of a 10hz note. The 100hz rule (which I just invented) is almost as accurate as the 1khz rule. At 100hz, most dynamic headphones have their highest impedance there, making it the easiest to drive frequency (which happens to be pretty audible bass.) Thankfully, like every dynamic headphone and their mom are easier to power than the 2012 LCD2.

 

If we look at the impedance rated for a headphone vs measured impedance, the rated impedance by the manufacturer tends to be the lowest impedance for a headphone at all audible frequencies (in other words, shows you the worst case scenario). HD800 has lowest impedance of about 330ish but Sennheiser rounds it down to 300 just to be safe. I guess that's why they call it "nominal impedance".

 

I've posted your question onto HA in case they have more to add.

[BoredErica]

Ahem.

 

HD800 has lowest impedance of about 330ish but Sennheiser rounds it down to 300 just to be safe.

Fixed some typos just now. 

 

Without getting into math (I don't have time to do that right now) the O2 has more than enough power to drive LCD-2's to ear bleeding levels.

I'll take you up on that. I better see some blood, mate. 

[BoredErica]

Thread has been updated with more minor typo fixes, removed a part that wasn't necessary (too many numbers). Added subsection titles and a new section addressing sensitivity readings at 1khz. It contains new info I have not previous discussed anywhere (including this thread). I've changed my reply regarding a headphone requiring differing amounts of power to play at a given frequency and db SPL.

[Lays]

Thread has been updated with more minor typo fixes, removed a part that wasn't necessary (too many numbers). Added subsection titles and a new section addressing sensitivity readings at 1khz. It contains new info I have not previous discussed anywhere (including this thread). I've changed my reply regarding a headphone requiring differing amounts of power to play at a given frequency and db SPL.

 

 

do this stuff for hd800 pls, i want to get dem someday

[BoredErica]

do this stuff for hd800 pls, i want to get dem someday

Data from Inner Fidelity:

Sensitivity: 102.3 db/Vrms

Lowest impedance: 345 Ω (No, I'm not willing to round down 45 Ω like Sennheiser lolz)

 

110db:

16.2 mw

2.4v

 

115db:

51.3mw

4.3v

 

120db:

162.2mw

7.67v

 

Lolz.

You can drive O2 to 119db without clipping, no problem, with a large margin left to go. But it can't do 120db without possibly clipping.  :lol: Each extra db is that many times more difficult to drive...

[Lays]

Data from Inner Fidelity:

Sensitivity: 102.3 db/Vrms

Lowest impedance: 345 Ω (No, I'm not willing to round down 45 Ω like Sennheiser lolz)

 

110db:

16.2 mw

2.4v

 

115db:

51.3mw

4.3v

 

120db:

162.2mw

7.67v

 

Lolz.

You can drive O2 to 119db without clipping, no problem, with a large margin left to go. But it can't do 120db without possibly clipping.  :lol: Each extra db is that many times more difficult to drive...

Cool my lyr will handle them no problem with tons of room to spare

[BoredErica]

Well, the HD800 isn't even hard to drive, lol. The M50x has a lower sensitivity than HD800.  If your Lyr can't drive M50x without room to spare, I'd be worried for you lol.

I've updated the OP to include voltage requirements of Lcd2.

[creatip123]

Well, the HD800 isn't even hard to drive, lol. The M50x has a lower sensitivity than HD800.  If your Lyr can't drive M50x without room to spare, I'd be worried for you lol.

I've updated the OP to include voltage requirements of Lcd2.

 

Phew just got the chance of back online. 

 

Ok, I asked a guy who 'should' know more about Audeze. The optimal amp power thingy, that's a recommendation. He's confident that latest release of Audezes are sensitive enough to be run by any players or smartphones. So an amp is not mandatory, but recommended, nevertheless. Now, if after saying that, the user asks, how big of an amp would be recommended, then that's the answer, 1-4W. I'm guessing, yes, to give room for inefficiencies and eliminate even the slightest possibilities of clips/distortions. That's my opinion though. He explained more, but I couldn't quite get all the words. My English is average only in written. Conversations are bad....

 

Oh and wizzie, he read this topic, and commended you on writing this.... :wub:

[BoredErica]

Oh and wizzie, he read this topic, and commended you on writing this.... :wub:

Guuuuuuuud.  B)

 He explained more, but I couldn't quite get all the words.

Can't copy and pasteyies?  :huh:

[creatip123]

Guuuuuuuud.  B)

 

 

Woootttt....you're not even gonna ask me who he was, or whether he was credible enough.....(hint: come on....ask me.... )

 

 

Can't copy and pasteyies?  :huh:

 

Ummm....we spoke face to face, not by e-mails.

[BoredErica]

Woootttt....you're not even gonna ask me who he was, or whether he was credible enough.....(hint: come on....ask me.... )

 

 

Ummm....we spoke face to face, not by e-mails.

Lemme guess... YOU SPOKE TO OUR LORD AND SAVIOR, NWAVGUY?!

Ermm... okie, who did you talk to?  :huh:  :wub:    :blink:  :wacko:  :unsure:    :huh: I read that you talked to an Audeze rep, although now I guess not.

 

And did he see the thread yesterday, after I made the thread nice and pretty?

[creatip123]

Lemme guess... YOU SPOKE TO OUR LORD AND SAVIOR, NWAVGUY?!

Ermm... okie, who did you talk to?  :huh:  :wub:    :blink:  :wacko:  :unsure:    :huh: I read that you talked to an Audeze rep, although now I guess not.

 

And did he see the thread yesterday, after I made the thread nice and pretty?

 

Lol, yeah, he's an Audeze rep, sorta.... I spoke to Alexander Rosson. 

 

 

I wonder what he was reading on the iPad??

 

 

 

Oh that's what he was reading.... :wub:

 

Oh, and I got you a souvenir:

 

 

:wub:

 

*I'm guessing @Lays is gonna have a boner over this post....

[BoredErica]

Lol, I see.  :lol: I actually imagined you were talking to him for some reason.   He looks pretty different from old pictures.

So how did he end up in my thread, you started asking him about LCD's power requirements? I bet he loved my cute little profile picture. I hope he saw my new juicy pictures I edited in yesterday.  (Probably not though.)

 

Alright guys.

This thread is now Audeze-approved. Disagree with it at your peril!!!  :angry:

 

(ur naught gunna mail me dat souvenier r u)

 

:wub:  :wub: :wub:

[creatip123]

Lol, I see.  :lol: I actually imagined you were talking to him for some reason.   He looks pretty different from old pictures.

So how did he end up in my thread, you started asking him about LCD's power requirements? I bet he loved my cute little profile picture. I hope he saw my new juicy pictures I edited in yesterday.  (Probably not though.)

 

Alright guys.

This thread is now Audeze-approved. Disagree with it at your peril!!!  :angry:

 

(ur naught gunna mail me dat souvenier r u)

 

:wub:  :wub: :wub:

 

Yeah, I specifically set out to find him to ask about your topic. The things I do for you..... :unsure:

 

To pop your balloons (y no evil emoticon....), he only did a speed read of the topic, and said 'this is interesting, I'll read more when I got the time', bcoz he was getting ready for other things, so I don't know if it's counted as 'officially approved' or not. I did suggest him to register to LTT, and give some insights. Mainly to avoid speculations and 'what-if' about Audezes. Dunno if he's gonna do that or not. He's been busy circling the globe atm.

 

*ummmm....souvenir cost: free. Actual souvenir cost: ~$1-$3. Shipping to USA cost: over $50  :wacko: