tinyman392
Be nice to noobs, we were all noobs at one point in our life.
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- Apr 27, 2011
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The Effects of Small Changes over a Frequency Range
OK, up until now, it has been widely believed that a 1 dB change could not be heard, and the test to this pointing users to test it themselves by increasing the entire amplitude of a sound by 1 dB… That data then goes on to FR graphs where we are widely made to believe that these same changes will make no audible change… Well, my curiosity struck me like this… Any instrument will provide more than one frequency of sound, some will product thousands of frequencies in a single note. So why are we comparing the change in one frequency instead of change in multiple… Because of the idea that a change in a single frequency isn’t large enough to be heard, that same change in multiple isn’t large enough either. We make this assumption, we use this assumption. Well, is it the right assumption, or are we really making an ass out of u and me?
Please note that for all tests done, I used the EQu app available for iOS to get more accurate EQuing that allowed me to do more. Although fully accuracy couldn’t be done in the first part of this test, the error created actually works against me here (allowing us to hear more change; you’ll see why it works against me in a bit). However, let’s look at what this entire test will look at:
Materials that I used for this test, although alternatives can definitely be used:
All tests were done in a room with no more than roughly 40 dB of noise heard from my location (used iPods’ Microphone along with 2 SPL loudness apps to test: UE SPL and MetalMed dB). I use roughly because it’s not 100% accurate, but the loudest noise was my laptop’s fan.
Now on to the test. For the first test, I wanted to see the effects of EQuing exactly 1 frequency (or as close to it) 4+ dB. In actuality I was EQuing a 100 Hz spike, but also had a few others around it spanning a few 1000 Hz. I started it at 4; started playing music. While the music was playing, I turned off the EQ for 10-20 seconds, then turned it back on for 10-20 seconds. I heard no change. I then opted to increase it more. When I hit around 5.5 dB, change was definitely apparent as that frequency started resonating a bit… However, it wasn’t as if that frequency was EQed 5.5 dB (or 4 when it was that low). In fact, I did hear small changes in the midrange, but they were just that, miniscule (definitely not even close to 2+ dB). So the results of this? EQuing a single frequency doesn’t do much in terms of changing sound. Obviously the only time this wouldn’t be true is if you were listing to a pure tone (or something close to a pure tone).
The Spike I used around 1k. As you can see, there are some small (< 1 dB increases around there as well)
The next test consisted of boosting the high-bass up 1 dB, due to EQu’s software stylings, it created a parametric curve through the entire spectrum. However, none of these changes were above 1 dB. This was to test the effects of boosting up 1 dB. What did I find out? With the Westones and the Phonaks, the sub-base frequencies were more apparent (bass guitars, etc) although not louder, they just had a better presence. Some of the midrange also became more audible (lower guitars). However, these were still minor changes. In some parts of songs, the change wasn’t audible at all. In other parts of the same song, it definitely was. Again, I retested by turning on and off EQ, switching songs, etc.
This is the mid-high-bass increase I Used. The increase between the 128 and 256 Hz is 1 dB.
My next test was to create a 1 dB boost in the mid-bass and mid-treble while reducing the mids by 1 dB. Again, all changes were 1 dB or lower. This created an EQ that resembled a sine/cosine wave (not exactly, but close). Changes were much more apparent. The Midrange definitely did sound much more recessed (as if it was a 2-3 dB drop). Again, I retested the same way I did before. These changes were much more audible and this test succeeded in getting change almost all the time. I really didn’t have to listen for the change, it just hit me. Again, this was a minor change, but enough to create a loss of detail/clarity along with some veiling.
This is the Sine wive EQ I used, nothing is changed above 1 dB. That is |change| < 1 dB; Change < (+/-)1 dB
So, what are we learning here? Well, it’s funny how a 4 dB increase (something that should be extremely audible) is almost not even audible compared to the 1 dB increase/decrease sine/cosine wave I created. Why is this? Why is it that the same 4 dB increase was less audible than the 1 dB increase in the high-bass (and mid-bass), which was barely audible? Simply put, our brains hear sounds bundled together… We hear a wide range of frequencies, not just 1 at a time. The data is acquired and meshed together (analogy) to create the perceived sound we hear. The fact is simple, we, as humans, hear sound through the entire frequency range, even little tiny ones, as opposed to one at a time.
Now, I’m going to do one little thing, I’m going to attempt to simulate, to the best of my ability, the changes found in Tyll’s 331 hour burn in of the K701s, to see if it’s audible. Now, upon looking at the graphs, we see 2 small increases in the treble area ranging around 2.5 dB, while the midrange gains around 1 dB… The bass changed .5 dB if it were lucky. So I attempted an EQ simulation of this, to see if it would be audible. Please note that this graph isn't 100% accurate, I tried to approximate the changes I saw to the best of my abilities. The changes are as follows< I have a .3 dB increase @ 32 Hz, and a .5 dB decrease between 128 and 256 Hz. There is a 1 dB increase from around 500 Hz to 2000 kHz and replicated spikes around 5 kHz and 10 kHz with 0 dB changes between them. From around 14 - 16 kHz there is -.4 dB change (if that).
This is my attempt at replicating the Frequency Graph K701 hour 331 - K701 hour 0. It's not 100% accurate, but still shows sign of change.
Well, as it turns out, things changed. Although they are all minor increases here and there, the changes were well apparent. Also note that lots of minor changes are why we upgrade headphones (if it wasn't for the minor changes 300+ dollar headphones give, we all would be using < 200 dollar headphones). For starters, the midrange “opened up”. That is, they became more airy and clear. Perception wise, things did sound more detailed. The treble became harsher for me, however, more detail was added in. A sense of smearing also came about. Now, the final addition was the increased presence of bass. This isn’t a quantity increase, it’s actually just a presence increase. Bass seemed more present, but not louder. Lower mids also became much clearer as well. However, the bass and lower-mids were not audible in every song I tested. In fact, the change was similar to the way the 1 dB increase of the bass (tested above) sounded (some change in this part, but not this, etc).
Comments, questions? Comment below. Have your own findings to give us? Comment below.
OK, up until now, it has been widely believed that a 1 dB change could not be heard, and the test to this pointing users to test it themselves by increasing the entire amplitude of a sound by 1 dB… That data then goes on to FR graphs where we are widely made to believe that these same changes will make no audible change… Well, my curiosity struck me like this… Any instrument will provide more than one frequency of sound, some will product thousands of frequencies in a single note. So why are we comparing the change in one frequency instead of change in multiple… Because of the idea that a change in a single frequency isn’t large enough to be heard, that same change in multiple isn’t large enough either. We make this assumption, we use this assumption. Well, is it the right assumption, or are we really making an ass out of u and me?
Please note that for all tests done, I used the EQu app available for iOS to get more accurate EQuing that allowed me to do more. Although fully accuracy couldn’t be done in the first part of this test, the error created actually works against me here (allowing us to hear more change; you’ll see why it works against me in a bit). However, let’s look at what this entire test will look at:
- The effects of EQing a single frequency 4+ dB
- The effects of EQuing a range of frequencies 1 dB up
- The effects of EQuing a range of frequencies 1 dB up in some areas, down in others
Materials that I used for this test, although alternatives can definitely be used:
- An iPod Touch (You obviously need a device)
- EQu EQing software (If you choose a different EQ more accurate the better)
- Phonak PFE 232s (Use your own headphones to repeat the test)
- Westone 4R (Use your own headphones to repeat the test)
- Although I only used 2 pairs of headphones on this test, both showed similar results in what I found out. I will be more than willing to retest (and probably will in the future) with other IEMs I own.
All tests were done in a room with no more than roughly 40 dB of noise heard from my location (used iPods’ Microphone along with 2 SPL loudness apps to test: UE SPL and MetalMed dB). I use roughly because it’s not 100% accurate, but the loudest noise was my laptop’s fan.
Now on to the test. For the first test, I wanted to see the effects of EQuing exactly 1 frequency (or as close to it) 4+ dB. In actuality I was EQuing a 100 Hz spike, but also had a few others around it spanning a few 1000 Hz. I started it at 4; started playing music. While the music was playing, I turned off the EQ for 10-20 seconds, then turned it back on for 10-20 seconds. I heard no change. I then opted to increase it more. When I hit around 5.5 dB, change was definitely apparent as that frequency started resonating a bit… However, it wasn’t as if that frequency was EQed 5.5 dB (or 4 when it was that low). In fact, I did hear small changes in the midrange, but they were just that, miniscule (definitely not even close to 2+ dB). So the results of this? EQuing a single frequency doesn’t do much in terms of changing sound. Obviously the only time this wouldn’t be true is if you were listing to a pure tone (or something close to a pure tone).
The Spike I used around 1k. As you can see, there are some small (< 1 dB increases around there as well)
The next test consisted of boosting the high-bass up 1 dB, due to EQu’s software stylings, it created a parametric curve through the entire spectrum. However, none of these changes were above 1 dB. This was to test the effects of boosting up 1 dB. What did I find out? With the Westones and the Phonaks, the sub-base frequencies were more apparent (bass guitars, etc) although not louder, they just had a better presence. Some of the midrange also became more audible (lower guitars). However, these were still minor changes. In some parts of songs, the change wasn’t audible at all. In other parts of the same song, it definitely was. Again, I retested by turning on and off EQ, switching songs, etc.
This is the mid-high-bass increase I Used. The increase between the 128 and 256 Hz is 1 dB.
My next test was to create a 1 dB boost in the mid-bass and mid-treble while reducing the mids by 1 dB. Again, all changes were 1 dB or lower. This created an EQ that resembled a sine/cosine wave (not exactly, but close). Changes were much more apparent. The Midrange definitely did sound much more recessed (as if it was a 2-3 dB drop). Again, I retested the same way I did before. These changes were much more audible and this test succeeded in getting change almost all the time. I really didn’t have to listen for the change, it just hit me. Again, this was a minor change, but enough to create a loss of detail/clarity along with some veiling.
This is the Sine wive EQ I used, nothing is changed above 1 dB. That is |change| < 1 dB; Change < (+/-)1 dB
So, what are we learning here? Well, it’s funny how a 4 dB increase (something that should be extremely audible) is almost not even audible compared to the 1 dB increase/decrease sine/cosine wave I created. Why is this? Why is it that the same 4 dB increase was less audible than the 1 dB increase in the high-bass (and mid-bass), which was barely audible? Simply put, our brains hear sounds bundled together… We hear a wide range of frequencies, not just 1 at a time. The data is acquired and meshed together (analogy) to create the perceived sound we hear. The fact is simple, we, as humans, hear sound through the entire frequency range, even little tiny ones, as opposed to one at a time.
Now, I’m going to do one little thing, I’m going to attempt to simulate, to the best of my ability, the changes found in Tyll’s 331 hour burn in of the K701s, to see if it’s audible. Now, upon looking at the graphs, we see 2 small increases in the treble area ranging around 2.5 dB, while the midrange gains around 1 dB… The bass changed .5 dB if it were lucky. So I attempted an EQ simulation of this, to see if it would be audible. Please note that this graph isn't 100% accurate, I tried to approximate the changes I saw to the best of my abilities. The changes are as follows< I have a .3 dB increase @ 32 Hz, and a .5 dB decrease between 128 and 256 Hz. There is a 1 dB increase from around 500 Hz to 2000 kHz and replicated spikes around 5 kHz and 10 kHz with 0 dB changes between them. From around 14 - 16 kHz there is -.4 dB change (if that).
This is my attempt at replicating the Frequency Graph K701 hour 331 - K701 hour 0. It's not 100% accurate, but still shows sign of change.
Well, as it turns out, things changed. Although they are all minor increases here and there, the changes were well apparent. Also note that lots of minor changes are why we upgrade headphones (if it wasn't for the minor changes 300+ dollar headphones give, we all would be using < 200 dollar headphones). For starters, the midrange “opened up”. That is, they became more airy and clear. Perception wise, things did sound more detailed. The treble became harsher for me, however, more detail was added in. A sense of smearing also came about. Now, the final addition was the increased presence of bass. This isn’t a quantity increase, it’s actually just a presence increase. Bass seemed more present, but not louder. Lower mids also became much clearer as well. However, the bass and lower-mids were not audible in every song I tested. In fact, the change was similar to the way the 1 dB increase of the bass (tested above) sounded (some change in this part, but not this, etc).
Comments, questions? Comment below. Have your own findings to give us? Comment below.