Skeptico Saloon: An Objectivist Joint
May 10, 2015 at 9:35 AM Post #1,606 of 1,671
You can't get medieval on an internet forum...it isn't like I am trying to convince him or that my answer is a end all, be all. I just offered a genuine answer as I am skeptical that multi-drivers can't offer a better performance than a single dynamic driver.

Again, your answer is an opinion. We're not interested in that. 
Who are you to decide that it would be pointless for me to ask an expert? I have an engineering degree from MIT, and I believe I would be more than qualified to understand the material if somebody explained it to me.

If you don't mind me asking, what field? If electrical, please help me in microelectronics: I'm getting slaughtered!
 
May 10, 2015 at 9:43 AM Post #1,607 of 1,671
Again, your answer is an opinion. We're not interested in that. 
If you don't mind me asking, what field? If electrical, please help me in microelectronics: I'm getting slaughtered!


Thermodynamics!! Sorry!!! I was slaughtered myself! :frowning2:
 
May 12, 2015 at 6:22 PM Post #1,611 of 1,671
Confession:
 
After nearly seven years on these forums, I've begun to wonder if I've been duped, by others and myself. I think I've subconsciously felt, as I've turned the volume up to slightly higher levels in ABing, that the ability to turn the volume pot on an amp less means that the sound is better. The closer I get to 3 o'clock, the more I've questioned the amps ability to drive the headphone at the same sound quality. Thus my previous approval of high gain over low gain and of more powerful amps over less. I think my feeling (perhaps mirrored by many on this forum, though not this thread) is that the the further I twist the volume pot, the less sound quality there is is and that the quicker it gets loud, the better the sound quality is. Of course, there are other psychological influences, such as the culticstatus of the designer, the cost, the impressions I've read, nationalistic sympathies, etc. 
 
I would love to ABX an E12 and a Pico Power (volume-matched) and see if I could hear a difference. 
 
May 12, 2015 at 7:10 PM Post #1,612 of 1,671
  Confession:
 
After nearly seven years on these forums, I've begun to wonder if I've been duped, by others and myself. I think I've subconsciously felt, as I've turned the volume up to slightly higher levels in ABing, that the ability to turn the volume pot on an amp less means that the sound is better. The closer I get to 3 o'clock, the more I've questioned the amps ability to drive the headphone at the same sound quality. Thus my previous approval of high gain over low gain and of more powerful amps over less. I think my feeling (perhaps mirrored by many on this forum, though not this thread) is that the the further I twist the volume pot, the less sound quality there is is and that the quicker it gets loud, the better the sound quality is. Of course, there are other psychological influences, such as the culticstatus of the designer, the cost, the impressions I've read, nationalistic sympathies, etc. 
 
I would love to ABX an E12 and a Pico Power (volume-matched) and see if I could hear a difference. 


it's a very well known effect of humans listening to sound. we use to say "louder is better". that's really how it alway feels(to a point where it's just too loud). and that's the very reason why we all insist soooooo much about volume matching before making an AB comparison. because else, and the guy trying to sell us something at the shop knows all about it, the louder will almost always sound the best to us.
 
I fool myself like that all the time, I get a new DAP, try it like a DAP, have fun, or not, think the bass is this or the soundstage is that. then I volume match it to another DAP, use a switch, make sure to use an IEM that is not going to be affected by impedance, and boom headshot, they usually sound almost perfectly identical. when I myself thought they were different from my uncontrolled listening session!
that's what so many people can't understand/accept. they trust themselves and just can't fathom to question anything they believe to be right. but do those guys do ABX? do they buy a switch? do they get something to match levels? of course not, we all are advocating for something blind, us for the test to be blind, while they do their best to keep themselves blind ^_^.
 
and high gain is almost always a bad choice. when the gain is a real one, it should be used to match the source feeding the amp, not the headphone.  and when it's just a glorified loudness setting, like on portable DAPs, then the lower value usually has the same of slightly better measurements and should be used only when more loudness is really needed.
 
edit: a nice way to see how loudness affects us, you just listen to your music, rise the volume for just a a sec or 2, and go back to the inithial loudness. for a time the sound won't be as good as it was before the test. going +5 then -5 doesn't end up feeling the same as doing nothing when it is the same. that's the kind of mess a human brain and the automatic dampening of our ear can do.
 
May 12, 2015 at 7:19 PM Post #1,613 of 1,671
Who gives a crap about all this stuff..I'm listening to the last Sufjan album, probably the worst recorded album of all time, and it brings me to tears without fail...I don't wanna listen to a Chesky (with all respect) bland jazz record because it has 200000 kHz mics..I still wanna listen to Sufjan recording himself on his iPhone
 
May 12, 2015 at 7:21 PM Post #1,614 of 1,671
  Confession:
 
After nearly seven years on these forums, I've begun to wonder if I've been duped, by others and myself. I think I've subconsciously felt, as I've turned the volume up to slightly higher levels in ABing, that the ability to turn the volume pot on an amp less means that the sound is better. The closer I get to 3 o'clock, the more I've questioned the amps ability to drive the headphone at the same sound quality. Thus my previous approval of high gain over low gain and of more powerful amps over less. I think my feeling (perhaps mirrored by many on this forum, though not this thread) is that the the further I twist the volume pot, the less sound quality there is is and that the quicker it gets loud, the better the sound quality is. Of course, there are other psychological influences, such as the culticstatus of the designer, the cost, the impressions I've read, nationalistic sympathies, etc. 
 
I would love to ABX an E12 and a Pico Power (volume-matched) and see if I could hear a difference. 

Google "Equal Loudness Contour" and "Fletcher-Munson"
 
May 12, 2015 at 7:22 PM Post #1,615 of 1,671
  Who gives a crap about all this stuff..I'm listening to the last Sufjan album, probably the worst recorded album of all time, and it brings me to tears without fail...I don't wanna listen to a Chesky (with all respect) bland jazz record because it has 200000 kHz mics..I still wanna listen to Sufjan recording himself on his iPhone

Then why are you even posting here?
 
May 12, 2015 at 7:33 PM Post #1,616 of 1,671
The multiplication by 2 is there so that the RMS level calculated for a 0 dBFS sine (rather than square) wave will be 0 dBFS. Without that, it would be -3.01 dBFS.

In other words, if the entire input is a simple sine wave at a constant level, the calculated dynamic range will be 0 dB. But it will be 0 dB even if only 20% or more of the input is a constant sine wave, and the rest of it is silence. Therefore, it is a pessimistic algorithm, because it will rate the track as having poor dynamic range if any substantial part of it looks like being heavily compressed. It also ignores a high peak in a single block due to using only the second highest peak value. If you take 5 minutes of high quality classical music, and paste a couple minutes of compressed metal or pop at the end of it, then the reported dynamic range will be based mostly on the latter, where the 20% highest RMS values are likely to be found.



The RMS sum is not based on the dB values, but rather on the power, which is the correct way to combine the RMS level for multiple blocks. That is, the correct overall RMS for the 12 blocks is:

10 * log10((10^(-5 / 10) * 5 + 10^(-5.3 / 10) * 5 + 10^(-5.8 / 10) * 2) / 12) = -5.25 dB

Interesting. I see. Thank you for clarifying that.

I know this is the SS section, but what would you say is an accurate measure of dynamic range? Obviously a pure sine wave is going to sound like 1 note to us, which might be the reason why the DR utility gives that a 0 rating, but music isn't just a simple sine wave. I have some chiptune music that I listen to on occasion and the DR rating is often around 3-7 (which is not unexpected for this music genre).

This particular song has a DR5 rating, and a crest factor of 6.9 I think (-9.4 dBFS RMS, -1.0 dBFS peak). If a perfect sine wave is the 0 point for the DR number, then the crest factor for this song divided by the crest factor for a sine wave (1.414) actually gets really close to the DR rating (4.8). These calculations are also a lot easier for me to understand than the math done in the DR specs.

[video]https://www.youtube.com/watch?v=KPaJLOIRJLI[/video]



I guess I've been been using the decibel units by mistake instead of the power all this time. When calculating power levels from dBFS values, what units would power be in this case? And how do I express the crest factor in terms of a decibel?

10 * log10(1.414) = 1.5 dB, but the actual value is twice that. Why is that so? I usually see 10 * log10(P1/P0), but sometimes I also see 20 * log10(P1/P0); when is 20 * used instead of 10 *?








[rule]
If I want to create a headphone measuring setup, what would be the most accurate way to do so?
From what I've seen there are two setups to do it:
  1. Use two microphones that measure flat and place them about a head's spacing apart; then just put the headphones over them and take measurements (the ideal headphone response in this case would be a flat line since it's just the headphone's sound being put into the microphones)
  2. Use two microphones that measure flat and place them about a head's spacing apart with silicone ears; then just put the headphones over them and take measurements (the ideal headphone response in this case would roughly resemble the head-related transfer function due to the pinnae amplification)

Setup #1 to me seems the most accurate because the HRTF from setup #2 can be variable depending on the ear's shape, material, size, etc. What would be the advantage of setup #2 and why is it that places like Innerfidelity and Golden Ears use a measurement setup similar to this instead of setup #1 where we know that if a headphone measures flat, it will follow the HRTF curve just like how flat-measuring speakers would be applied to our ears?
 
May 12, 2015 at 7:46 PM Post #1,617 of 1,671
I compared crest factor vs the DR rating for my whole collection a while back, and as you'd expect they correlate decently well. The tracks off the trend had exactly the kinds of behavior you'd expect to yield such a result. For instance, if a track has only one large peak, the crest factor can come out high but the DR rating will come out low (since it uses the 2nd highest peak value).
 
May 12, 2015 at 7:56 PM Post #1,618 of 1,671
I compared crest factor vs the DR rating for my whole collection a while back, and as you'd expect they correlate decently well. The tracks off the trend had exactly the kinds of behavior you'd expect to yield such a result. For instance, if a track has only one large peak, the crest factor can come out high but the DR rating will come out low (since it uses the 2nd highest peak value).

I just did a quick calculation for AC/DC's "Back in Black" that I have from their 2003 remastered CD.

The track has a lot of clipping, so Audacity says the peak is 0 dBFS, obviously. The DR utility agrees. 10^(0/10) = 1

Audacity then says the track's RMS value is -12.65 dBFS. The DR utility says it's -9.07 dBFS. 10^(-12.65/10) = 0.054325

Crest factor = peak / RMS = 1 / 0.054325 = 18.4077

Crest factor / crest factor full scale sine wave = 18.4077 / 1.414 = 13.02

A full-scale sine wave has a crest factor of 1.99? (0 dBFS peak, -3.0 dBFS RMS). 18.4077 / 1.99 = 9.22, which is a lot closer. Now I'm just confused though because in my previous post, I used 1.414 and I got the same DR rating. >.>

DR utility says it's DR8.


In this case, what would be a better indication of the track's dynamic range?
 
May 12, 2015 at 8:19 PM Post #1,619 of 1,671
I just did a quick calculation for AC/DC's "Back in Black" that I have from their 2003 remastered CD.

The track has a lot of clipping, so Audacity says the peak is 0 dBFS, obviously. The DR utility agrees. 10^(0/10) = 1

Audacity then says the track's RMS value is -12.65 dBFS. The DR utility says it's -9.07 dBFS. 10^(-12.65/10) = 0.054325

Crest factor = peak / RMS = 1 / 0.054325 = 18.4077

Crest factor / crest factor full scale sine wave = 18.4077 / 1.414 = 13.02

A full-scale sine wave has a crest factor of 1.99. 18.4077 / 1.99 = 9.22, which is a lot closer. Now I'm just confused though because in my previous post, I used 1.414 and I got the same DR rating. >.>

DR utility says it's DR8.


In this case, what would be a better indication of the track's dynamic range?

 
I think these measurements are best used to compare different masters of the same piece, rather than as absolute measures (especially given that they can disagree on the assessment of certain tracks). Here's the graph I got of DR rating versus log10(crest) for what part of my collection I've ripped (haven't made the log-scale ticks work yet, sorry):
https://drive.google.com/file/d/0BwmVtb5IwniEV2JkQXloLVd5ZnM/view?usp=sharing
 
May 12, 2015 at 10:48 PM Post #1,620 of 1,671
yeah I wouldn't take DR as a an actual measurement of dynamic. the aim is more to give a general idea and help avoid overly compressed releases of one album thank to the website. it's useful, but it's not the best thing there is to measure actual dynamic. not that actual dynamic is in itself a perfect tool to say if a song is dynamic, it could just have a few very long quiet passages before going back to brickwalling and the absolute dynamic would look great.
I find that looking at the track in audacity or anything like that(I use s(M)exoscope in foobar for fast check), is a better teller of how brickwalled a track was.
 

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