I'm sorry but that would be very different analogy. The frequency response graph is very different from graph that record track of the song. The coupler works as "microphone" that capture the response from the IEM, with sine sweeps.
sine sweeps 20hz-20,000hz every frequencies, so the software (in this case REW) will output a sine sweep from 20hz until 20,000hz and then capture "how big the bass at 20hz on blessing 2 for example, and how big the bass on 20hz with the same sine sweep with blessing 3 for example, move to 21hz, 22hz, 23hz until 20,000hz
So here you can see how big the sub bass on 35hz in blessing 2, compared with sub bass of another IEM on the same 35hz, or any other frequencies.
This is how the FR graphs process works. It's not like capture the graph from a song.
the graph from a music track will be like this instead :
This contains all vocals, percussions, other instruments but we cant actually "hear" from see this graph, meanwhile totally different from frequency response graph
graph by Mr Sally Super Review
This is the example of Frequency graph, its clearly showing from neutral point (350hz-800hz), the sub bass on 30hz is up by +10db increment.
Then if you know what instrument or what sound sit there, you will be able to imagine, can't be piano or cymbals there right? Sound of the contra bass are there, or low strum bass guitar, or extension of kick drum if deep enough.
Move up to mid bass, around 100hz, these area, where the first kick drum hit the transient of the kick drum, the texture of the bass, the upper notes of bass guitar, the toms of the drum are heard here. This quintet is tuned well and +5db from neutral point (350hz-800hz) is ideal for me, it provides enough warmness and texture, while not bleeding to the mids
Now to high mids around 2-4khz, the pinna gain, these are emphasize of female vocals, too high on this 2-4khz area, will lead to shouty vocals. Too low will result to recessed female vocals. Together with all instruments down there, the piano, the guitars, saxophone, trumpet on those frequencies
Mid trebles on 8khz, where the grapher usually put the resonance peak here to have standardize FR, sometimes can shown higher than it should because of the resonance peak, but sometimes just as accurate, this 8khz are trails of hihats, cymbals and air, and can perceived as "low air" and can be boosted to have wider soundstage perception
upper trebles / extension past 10khz, is where technicalities sit, on around 12-13khz thats why lot of TOTL sets are having this region bigger than neutral point (see 350hz-800hz level) while 15khz are more airy presentation.
That just a glimpse of "basic" understanding to read the graph, once you know how to read the graph, it can be very useful , to save your wallet mostly
More advanced reading can be put this example:
how "thin or thick mids are produced?" its about the balance between lower mids (300-500hz) and high mids (2-4khz) region, the further they are apart the thinner the mids, the closer they are, the thicker the mids. So big bass doesn't guarantee you have thick mids, for example " Moondrop Variations.
safe trebles but sounded "tizzy" = balance between lower trebles on 6khz and the trails of its transient that lies on 8khz
and there are also "mandatory dips" like on 7khz for examples, to avoid sibilances because of the "too much trebles at the same time" and as opposite there are little peaks, that can be heard as "transient attack" that perceived as crispy or sharp note attack that have correlation with "resolution"
----------------
That why I said this all like easy to learn, hard to master thingy, and you can only get better by having the measurement rig and do measuring again and again, comparing the result with your ears again and again and again, like years, not months, not days
The other way to help is with playing with EQ, yes I like to borrow
@o0genesis0o words graphs is like EQ, its similar the FR graph is reflect how manufacturer permanently EQed their IEMs, it's how they tuned the IEM. with EQing we can know what sound sit on certain frequencies, maybe like try to EQ 4khz , the presence region by +5db, oh the IEM now sounded high resolution suddenly, crispy guitar notes with sharp attack. put down that and EQ other frequency, maybe 50hz, ow the punch of the bass become so impactful but without bleed the mids, and any other frequencies.
I learned the hard way really. I spent more than $10,000 for audio hobbies, fight sessions with wife, time, etc and guess what?
$100 for the measurement rig
more than $9,900 for hit and miss IEMs (well also count for DAPs, dongles, eartips, etc)
The graph reading can save you thousand bucks, without blind buying
So again I would say the graphs isn't 100% accurate, but quite helpful like give you 70% of how the tonality like, like a said "synopsis" of the movie before you decide to buy the ticket. but lot things can't captured by this rig, like bass smears, how dampened is the sound, the cross over below the highest FR (FR only capture the highest sine sweeps sound), etc.
For Example if I have Quartet, and I want to buy Quintet. aside from friend's recommendation you can compare it directly with your current IEM as cue
They have roughly similar sub bass, but at 100hz, the Quartet is more bass bleed, for me it's a good thing but for someone who prefer bigger mid bass than quartet, they can save the money because the quintet will be lower in midbass
the Quintet have forwarded high mids at 2-4khz than Quartet, if that your thing, you can go ahead or you're looking for more trebles, see 6khz until 15khz, definitely more trebles and details and extension.
This is just a simple example to make it as basic comparison, but once you at some point you can really know roughly how the sound of the IEM just by looking at the graph, again the rough tonality around 70% aside from the things that cant be capture by the rig like I said above.
Yes correct, definitely agree.
exactly
These are real case now :
see 10-15khz, definitely Quintet have the extension of the trebles while the rest aren't (rolled off). So when I buy Orchestra lite and expect good treble extension, it could be wrong move, I can save money and buy Quintet instead.
) . There are forum members, that I take their opinions more seriously than others, but their preferred sound signature differs from mine; so when they expound on the virtues of a frequency response range that's not their priority . . .
