BoredErica

The thread is ONE AND A HALF YEARS OLD, WHAT HAVE YOU DONE CICCIOOOO

Guys, it's fine. It was an auction you see, not a sale. 🙂
xD

Guys, it's fine. It was an auction you see, not a sale. 🙂
xD

Guys, it's fine. It was an auction you see, not a sale. 🙂
xD

Guys, it's fine. It was an auction you see, not a sale. 🙂
xD

Already mentioned by 5 others so I am simply echoing their sentiments: Is it possible to test Displayport? Level1techs had a whole video about how some DP cables are causing all kinds of problems. He specifically mentioned how people tended to get good results from Club3d.
 
Imo debunking audiophile snake oil is not as important right now. We have people struggling to get their gaming to work normally on DP and it's only going to get a lot worse when next gen DP is the norm.
 
Also uh, somehow Monoprice has a dp2.0 cable for sale already.

Already mentioned by 5 others so I am simply echoing their sentiments: Is it possible to test Displayport? Level1techs had a whole video about how some DP cables are causing all kinds of problems. He specifically mentioned how people tended to get good results from Club3d.
 
Imo debunking audiophile snake oil is not as important right now. We have people struggling to get their gaming to work normally on DP and it's only going to get a lot worse when next gen DP is the norm.
 
Also uh, somehow Monoprice has a dp2.0 cable for sale already.

Already mentioned by 5 others so I am simply echoing their sentiments: Is it possible to test Displayport? Level1techs had a whole video about how some DP cables are causing all kinds of problems. He specifically mentioned how people tended to get good results from Club3d.
 
Imo debunking audiophile snake oil is not as important right now. We have people struggling to get their gaming to work normally on DP and it's only going to get a lot worse when next gen DP is the norm.
 
Also uh, somehow Monoprice has a dp2.0 cable for sale already.

Already mentioned by 5 others so I am simply echoing their sentiments: Is it possible to test Displayport? Level1techs had a whole video about how some DP cables are causing all kinds of problems. He specifically mentioned how people tended to get good results from Club3d.
 
Imo debunking audiophile snake oil is not as important right now. We have people struggling to get their gaming to work normally on DP and it's only going to get a lot worse when next gen DP is the norm.
 
Also uh, somehow Monoprice has a dp2.0 cable for sale already.

Seems my mom is starting to come around on the LGBT thing a little bit. Not all the way, but... wait, has hell frozen over already? 😯
Also, how about that Title VII Supreme Court ruling? Eh?
 
In other news, people continue to ask me to smile in my portraits. Multiple people. Many people.

I think any shallower depth of field and the image is made worse. I want to see a bit of the background and make out what I'm seeing kindda.

The subject is kind of boring. I guess it's done technically right, but I feel like artistically it's not that interesting, but I find it interesting for some reason. it's kindda the exact reverse of the title, but I can't read and I've already committed to posting this comment.
 
I like pictures sometimes of chain link fences which transition from pretty sharp to blurry gradually. The radiators kind of remind me of that. And I love that bag in the background. Nice to add a dash of pink and chocolate to the image.

Mom came back to live with us for 2 years. Stress has increased due to that. She's an anti-trans conservative, but we also don't get along on many apolitical levels.
 
Dropped a "friend" few days ago. Don't feel like having friends who think I'm delusional.
 
Preparing for incoming recession. Going to ask for more hours to shore up net worth. It's a little trickier than that but not going to get into that right now.

Wew, I changed my username.
 
I feel like for the most part online it's best not to reveal or hint I'm trans. It always causes somebody to have a problem with me, which just causes more problems than I want to deal with.

Hi ?

Intro by XX!
I like.

Got my name and gender legally changed! Filed with social security, driver's license incoming too.
 
Yayyyyy

Got my name and gender legally changed! Filed with social security, driver's license incoming too.
 
Yayyyyy

Got my name and gender legally changed! Filed with social security, driver's license incoming too.
 
Yayyyyy

Got my name and gender legally changed! Filed with social security, driver's license incoming too.
 
Yayyyyy

Got my name and gender legally changed! Filed with social security, driver's license incoming too.
 
Yayyyyy

The feels when my skin is softer than my girl friend's now  

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

meep
 

Help Lady Fitzgerald, dumb people are being dumb to me on OCN! RETREAT BACK TO LTT, A FUNCTIONAL FORUM!
 
 
My mom does not understand how to support her children emotionally, and I've tried to explain it to her multiple times but it just goes over her head. The entire concept is incomprehensible to her. She's from an older generation in an Eastern culture and barely ever had a mother, so I guess I can see where it comes from.
 
 
In other news, if Alex Jones is right that people are putting chemicals in the water to feminize the population, I'll make sure to drink a few cups every day. 

They're fun until they keep meowing for no reason and somebody has to clean their mess up. I have rads way above the floor to avoid cat hair armageddon.