Videos don't do well on Hacker News, but I encourage people to at least watch the first couple minutes of this one. The oscilloscope visual overlay is interesting and the editing is really good.

Also, given the topic (audio equalizers) there's no way it could have been a blog post.

OK, so based on this video, I've turned on EasyEffects, added an Equalizer, set the input source to "Easy Effects Source" in the system settings, started playing pink noise, then tried to adjust the dials until the input looked closer to a horizontal line (it's very chaotic so that is hard to do).

As some sections of the video highlight it ended up needing to dip the mids and boots the lows and highs. This is my end result (so far, I'm probably going to tweak this continuously):

    Preamp: -1 db
    Filter 1: ON PK Fc 27.782795 Hz Gain -3.36 dB Q 1.7848856
    Filter 2: ON PK Fc 49.40557 Hz Gain 1.09 dB Q 1.7848856
    Filter 3: ON PK Fc 87.85691 Hz Gain 5.04 dB Q 1.7848856
    Filter 4: ON PK Fc 156.23413 Hz Gain 6.43 dB Q 1.7848856
    Filter 5: ON PK Fc 277.82794 Hz Gain 3.76 dB Q 1.7848856
    Filter 6: ON PK Fc 494.0557 Hz Gain -1.19 dB Q 1.7848856
    Filter 7: ON PK Fc 878.5691 Hz Gain -5.54 dB Q 1.7848856
    Filter 8: ON PK Fc 1562.3413 Hz Gain -3.96 dB Q 1.7848856
    Filter 9: ON PK Fc 2778.2793 Hz Gain -2.97 dB Q 1.7848856
    Filter 10: ON PK Fc 4940.557 Hz Gain 0.3 dB Q 1.7848856
    Filter 11: ON PK Fc 8785.69 Hz Gain 4.35 dB Q 1.7848856
    Filter 12: ON PK Fc 15623.413 Hz Gain 8.7 dB Q 1.7848856

TUXEDO InfinityBook Pro 15 - Gen10 - AMD Laptop Speakers.

It does make a positive difference (why don't they teach us this in school? ;) ). Please note I am music illiterate.

EDIT: it looks like changing the input source has no actual effect, just need to make sure the internal microphone's volume is not muted, and have to keep system setting window open while doing this, maybe the microphone is no longer on when the window is closed?. Linux is weird sometimes.

I think the title on HN is misleading. Sadly I’m not sure what’s the short and clearest title :(

The video is very nicely made and it focus on sound systems / boomboxes frequency response and behavior of included filtering modes.

So when talking about EQs with “all forms” in mind, you should consider:

- EQ is merely combination of one or more filters.

- There are many common filter designs, the video isn’t about that, it also doesn’t mentioned Low-pass/High-pass/band-pass/bell or common structures, but it is only showing them.

- Filters made and behave differently

- Most filters (including the ones in the video) are done on the time domain (vs spectral one)

- Phase, this is the biggest missing piece in the video imho. Naive filtering is “smearing” the signal to achieve the different tone balance. By doing so, they also most likely change the phase (unless using linear phase filters)

- Filtering might result delay in time.

My music listening speakers have two built in power amplifiers (one for the tweeter, one for the woofer) and have a DSP feeding right into a DAC, feeding right into those amplifiers.

There's a control box that comes with them, and when you plug a calibrated microphone into that box, and put it in the listening position, you can get it to do some frequency sweeps, one at a time, then they calculate a correction curve for each speaker, based on the actual response of the particular speaker in the particular room, and program that curve into the DSP of the speaker.

It's like night and day toggling the calibration on and off while listening to music.

And yes, as he says, the best hi-fi is just professional audio gear..

My music listening setup is simply a USB->AES converter box that feeds directly into the monitors, the monitors are a pair of Genelec 8050, and then the GLM box and volume knob. Never heard "hi fi" coming even close to it, not at the price, not at five times the price.

Same goes for headphones, you can't get much better than the simple and cheap DT990 (or 770 if you want them closed), sure, you can pay about 10 times as much for some Sennheiser hd800s, and those are pretty good, and I do have a pair of HE1000se, which are not only cheaper, but actually sound better too. But I'd never recommend anyone who's not as stupid as myself to buy anything "above" DT990.. And yeah, I EQ my headphones with a dbx 231x two channel 31 band EQ, and while that's not as scientific as the calibrated monitors, for a headphone listening experience, it gets pretty good.

I tried to post Posy's videos a few times here, but with no bigger interest.

His videos about LCD technology are hypnotizing. Bonus - he makes all the music.

Oh, that's really cool, the channel seems like it has a lot of other nice videos as well!

I wish there was a video that's so nice about compressors, like in Audacity you have all of these settings and most are also present in OBS and other software:

  * Threshold (dB)
  * Make-up gain (dB)
  * Knee width (dB)
  * Ratio
  * Lookahead (ms)
  * Attack (ms)
  * Release (ms)

"The best hifis are professional equipment"

This is gold. I wish so many people understood and used this. Pro equipment is more robust and more versatile. And if you know some people you can get amazing used stuff at bargain prices from your local musicians or sound engineers. Lot of times, people I know (and I too, though I'm not a pro sound engineer) will help you choose and setup just because you showed interest in the things we are interested in. Beers are assumed.

One drawback is that pro audio stuff may look ugly to non pro people. I made my wife listen to the cheapest studio monitors I could find on amazon, equalized with the same pink noise method in this video, and compare it to her bose and marshall speakers. She liked the sound better but my speakers are "yuck ugly" :(

In the 70s/80s every home stereo system -- racks of stereo equipment stacked a meter high -- had a dedicated equalizer. It was not just for audiophiles!

For the earlier systems with the bass boosts, are the graphs showing what comes out of the cables or what comes out of the speakers?

I would assume they don't care about the very low bass because they were designed as a unit and physically couldn't produce those notes very well anyway. Hence the need to boost slightly higher frequencies to fake bass.

The second sentence in the video hides a bit of complexity. Pink noise isn't a straight line on the spectrum analyzer unless a correction slope is active, and the common settings for the slope (3, 4.5) are just a convention.

I guess, that's why it says "you can make it look like a straight line".

I love Posy's channel so much. Really beautiful love letters to all kinds of vintage tech (plus his own music!).

Can measurements and calibration be done easily at home to see if your sound system is well calibrated ?

I was thinking of playing a pink noise on the speaker and recording it with a cheap microphone or displaying it with the Spectroid app, but the microphone probably has it's own frequency response.

Is there an App for that ? With each phone model microphone factory calibrated ?

Is there a way to use known fact about physics like harmonics should have a specific shape (timbres) that's should help equalize frequency with respect to each other ? Or from various microphone positions, calibrate it so that any cheap microphone can do the trick ?

The history behind vU meters is also fascinating. People used to calibrate off the BBC techs, or off American techs.

No BIPM, no SI units: what the BBC say.

Posy’s videos are always incredibly creative and beautiful celebrations of retro tech.

From the title, I expected Neve and Pultec, not 90s HiFi and digital EQs. :(

I knew this was a Posy video before even opening the link.

A pleasant, if muted, layman's 10 minute journey to explain sound, eq, and speaker response. It gets juiciest on room eq correction/compensation, approaching the 9 minute mark.

Very first sentence: "This is pink noise... if you measure it, you can make it look like a straight line."

He then shows a horizontal straight line: that's white noise?

Posy my beloved

This is a fantastic yt channel!

Couldn't hear this video, just watch, because I have no sound in the env I am currently in. But some thoughts about EQ.

"EQ isn't phase shift, phase shift is EQ.", a video title I saw once, but hits the nail on the head.

"Nothing is for free.", if you eq some frequencies, you affect some other frequencies too. You can use this to your advantage, if you are aware of this.

"EQ graphs are lying." Lack of resolution and not revealing the phase shift makes most stock EQ graphs not telling the truth.

"My hearing aids sound strange/metallic." This is the phase shift, you are hearing.

Have a nice Sunday everybody!

Is equaliser an alternative spelling, perhaps in British English? I ask because there's a mathematical entity called an equaliser.

https://en.wikipedia.org/wiki/Equaliser_(mathematics)

These graphs show only amplitude, not phase shift.

Looks like an incomplete approach if you ask me.