[HN Gopher] Show HN: HiFiScan, a Python app to optimize your lou... ___________________________________________________________________ Show HN: HiFiScan, a Python app to optimize your loudspeakers Author : erdewit Score : 207 points Date : 2022-09-11 11:59 UTC (11 hours ago) (HTM) web link (github.com) (TXT) w3m dump (github.com) | ttpphd wrote: | I'm a psychoacoustician and this is not the way, very sorry to | report. Others have touched on the acoustic issues already, so | let me touch on the psychological ones: your perception of sound | from loudspeakers doesn't just depend on the acoustic waves | hitting your ears. It also depends on your personality and | expectations. If you genuinely believe that doing a seance to | drive out the poltergeist from your speaker set up will make the | sound better, it will be difficult to convince you otherwise | precisely because the acoustics did not actually perceptibly | change. | stdbrouw wrote: | "Frequency response does not matter because other things also | matter and I have a PhD in these other things." This is a | complete non-argument. | kekebo wrote: | It's an unwritten rule in the studio scene around me to have a | specific fader that is prominently placed but does nothing. To | use when certain musicians (usually guitarists) demand to raise | the gain of their instrument into unreasonable territory. Seems | to work reliably to look at them and very slowly raise that | fader until the they say it's good | bityard wrote: | > If you genuinely believe that doing a seance to drive out the | poltergeist from your speaker set up will make the sound | better, it will be difficult to convince you otherwise | | I think you just found the next big thing in audiophile fads | willismichael wrote: | I'm more interested in inviting the right kind of poltergeist | to dwell in my speaker set up, to give playback the warm | paranormal sound that is clearly missing from sterile | exorcized speakers. | aeturnum wrote: | A friend loaned me a fancy usb DAC a while back and I used it | to listen to music while I worked. After about a day or so I | asked her if it was my imagination or if the audio really did | sound better. Her answer was that there's no difference between | those situations: if I imagine it sounds better, it does sound | better. | willis936 wrote: | I don't have to use my imagination to hear the signals | coupled into my USB DAC when I move my mouse. They're really | there and I really don't want them to be. | archi42 wrote: | Depends on the USB DAC, and maybe/probably the PC. I don't | have/hear interference with my current setup. I did have | the issue with another DAC; IIRC I put an RC filter into | the USB cable power lines (or did I just add an R into the | ground line? Do some research if you plan on trying this). | | PCs these days often still have an optical toslink, that | can be used to avoid the issue. | willis936 wrote: | I have an ODAC+O2. They're not easy to source for cheap | these days. My issue is that the power supply filtering | inductor has a cracked iron core (due to me being | clumsy). The cheapest solution would be to replace it, | but it's not super easy to swap out surface mount | components. | | I'll just deal with it by keeping the O2 volume low and | cranking the volume on a second amp. Long term I'll just | buy an element or a schiit. | IshKebab wrote: | Nonsense. Not everyone is an "audiophile" (in a bad sense) who | believes in silver speaker cables. | ptk wrote: | I genuinely wasn't sure whether psychoacoustician was a cheeky | synonym for audiophile or not. :). I looked it up and, sure | enough, psychoacoustics is a legitimate field of study. | amelius wrote: | How does this compare to just buying a good headphone? | jensgk wrote: | Headphones should also be calibrated by doing EQ. See | https://www.reddit.com/r/oratory1990/wiki/index/list_of_pres... | timc3 wrote: | Headphones are excellent, but I find I have a different | experience with headphones compared to music coming out of | speakers. Sometimes I prefer one over the other. | analog31 wrote: | A good headphone can probably still outperform a speaker | system. The tradeoff is that you have to wear a headphone. In | my case, I just hate them. It's just more pleasant for me to | listen from speakers, despite the fidelity tradeoff. | vladvasiliu wrote: | There's also the fact that when you really get "into" the | music and start moving your head, there are basically two | scenarios: you either get the "hum" of the headphones moving | on your ears, or the headphones stay put but the clamp is so | tight that you can't stand them for more than 10 minutes. | scns wrote: | Try good half-open cans like Beyedynamic DT880. I can wear | them all day. | archi42 wrote: | I never really liked wearing headphones as well. I've setup | my room such that I can use the big stereo speakers plus a | decent mic (Samson Go Mic) for voice chats. | | However, Sennheiser HD650 are a pleasure to wear. Even for | longer periods of time. I use them with a bluetooth+USB | DAC/amp (Fiio Q5; outdated) and a short cable; so I'm pretty | flexible how I can use them. | zihotki wrote: | I wonder what are the differences between this tool and industry | standard REW app - https://www.roomeqwizard.com/ | amluto wrote: | Source code, for one. | TacticalCoder wrote: | Isn't it basically what "DRC" does? (Digital Room Correction) | | https://en.wikipedia.org/wiki/Digital_room_correction | | I don't remember the exact order but way, way, way before the $10 | K USD digital audio cable snake oil, audiophiles are going to say | that DRC is the second single biggest thing that can enhance the | quality of your setup (the first one being which speakers you're | using and how you place them). Then source quality/amp/dac. And | only way further down the line, for those who believe in voodoo, | $10 K digital audio cables. | timc3 wrote: | Seems to be some kind of DRC. | | $10K digital audio cables are never a good idea. | | I remember I went to some audiophiles house once to demo some | speakers, and his "hobby" seemed to have taken over the house | and common sense. He had crazy expensive audio equipment and | some of the thickest cables I have seen, with the cables all | suspended on little bridges. | | All this in a room which was basically a square brick | construction with glass windows on 3 sides, no thought to any | treatment. He didn't seem to understand that the room was | effecting the sound more than any DAC, Amp, Cable, or any of | the other voodoo that was going on. I couldn't properly demo | the speakers because of a particular standing wave. I concluded | he probably had a hearing problem, he concluded he needed to | upgrade a cable. | simondotau wrote: | An objectivist audiophile would say that room correction is | among the three or four _grossly consequential_ parts of the | audio chain. They are, in serial order: | | 0. Source material | | 1. Room correction DSP | | 2. Speakers (including subwoofers and crossover configuration) | | 3. Room acoustics (including positioning of speakers and | listeners) | | 4. The human (ears, experience, expectations, ego, etc.) | | All of the above are more consequential than anything else, | assuming the core components are not total garbage, | underspecified or malfunctioning. This includes the DAC and | amplification. | | Of the above list, I would place room correction at the bottom. | It is the cherry on top of a great system, not the means to | achieving greatness. And it lets you get away with some things | (most notably, mismatched speakers) to a greater extent than | otherwise. But despite the name it can't fix real acoustic | problems. | IAmGraydon wrote: | I'm not an audiophile in the obsessive-compulsive sense, but I've | been recording music in my home studio for 20 years and I know my | way around it. This sort of calibration is not ideal. Not only | are you measuring with a device that has an imperfect response | curve, but you are also measuring the room at a single monophonic | point in space. The way that sound interacts with the room and | your ears is far more complex than that. Ultimately, this is a | bandaid for a poorly treated room. If you're serious about | getting a flat response curve from your monitoring room, you're | far better off learning how to treat the room properly and how to | position your monitors within the room for the best results. | vladvasiliu wrote: | > you're far better off learning how to treat the room properly | | Would you have some pointers on this? | | I've been looking into this and while I've found pointers on | "what to do", what's missing is where to actually find the | necessary panels and how to figure if they're actually worth | anything. | zoltar wrote: | Here's some basic before/after examples that might be useful. | This is kind of a deep rabbit hole. My dumb brain still | dreams of blackbird studio c every once and a while. | | https://www.youtube.com/watch?v=dB8H0HFMylo#t=6m22s | colanderman wrote: | I've found https://ehomerecordingstudio.com/acoustic- | treatment/ to be a well-written and informative guide. | its_bbq wrote: | Build your own panels with rockwool insulation. There way | better than almost anything you'll find on the market and | easy even for no talent carpenters like myself | vladvasiliu wrote: | How do you cover those? I'd expect drywall or similar would | negate most benefits. | timc3 wrote: | Fabric that you can breath through easily for looks. | Under than you can be very thin fabric that makes sure | that the fibres from the insulation doesn't escape. | | I use this for looks: https://www.camirafabrics.com/en/co | ntract/inspiration/acoust... | timc3 wrote: | Exactly. If you really want to get into it the depth of the | construction of the panels you need is based on some maths | - density of the insulation material and it's particular | properties but all of that can be found out on forums such | as this one: https://gearspace.com/board/studio-building- | acoustics/ - vs the frequencies you wish to treat. | | You can put your room dimensions into a calculator and get | a rough idea of some of the try and find the modes of the | room - which you want to treat, though sometimes it takes | trial and error as well. But you want to treat the point of | first reflection and then have bass trapping in the | corners. | | Don't buy that "acoustic foam" that looks like egg cartons, | it's rubbish. | ibigb wrote: | You might look here: http://realtraps.com | | You can probably reduce some room resonances. | drcongo wrote: | You'd also be relying very heavily on the microphone used to | measure it. | OJFord wrote: | That's the 'device with an imperfect response curve', I | assume. | | In fairness, the readme does state: | | > A good microphone is needed, with a wide frequency range | and preferably with a flat frequency response. | | By 'preferably' I assume it's implied that it can curve-fit | (whatever's needed, I know next to nothing about this) to a | non-flat microphone response, as long as it's known, but if | it's flat then no need. | | If it's unknown (and non-flat or assumed non-flat because | it's cheap and doesn't make any claims about it) then that's | the real problem, no point trying to do anything because it's | like trying to construct a level floor with a shoelace for a | spirit level. | rodgerd wrote: | Commercial systems that do this kind of room correction | generally have a limited range of recommended microphones, | and the more expensive (and hopefully better) ones will | have the microphone calibrated and factored into the room | correction - for example, Anthem's Room Correction (ARC) | ships mics that have a serial number. You plug that into | the ARC software, it looks up the factory profile of that | specific mic, as it was recorded at build time, and weights | the calibration for it. | retcore wrote: | Here's a measurement standard mic: | | https://earthworksaudio.com/measurement-microphones/m23/ | leeoniya wrote: | i always wondered, is it possible to take a cheaper mic or | iems and "flatten" them via an eq, to perform nearly as | well as professional gear that's 3x the price? | | i just picked up a pair of KZ AS06 iems [1] and my | listening preference is U shaped (which is how these are | dialed in out of the box), but i imagine with quality | hardware and e.g. 3+ dedicated, drivers it should be | possible to flatten them out in an eq. | | [1] https://old.reddit.com/r/headphones/comments/eqpsen/kz_ | as06_... | mastax wrote: | Yes, to an extent, and this is frequently done to great | effect. However frequency response isn't everything, | there's also e.g. group delay, off axis response, and | harmonic distortion. In particular, boosting response in | areas a speaker is deficient often causes a huge increase | in distortion, so you have to balance. | LeSaucy wrote: | How does this compare to dirac? | tpict wrote: | I'm finding the "this is a horrible idea" responses amusing. I | don't know if there's something fundamentally different about | the way this project works versus Dirac/XT32 or if the | naysayers aren't familiar with it. Or maybe there's an anti- | room correction sect of audiophiles that have remained hidden | to me. | stinos wrote: | Not 'fundamentally', but using one single point would | probably be the main issue. Move the microphone 5cm and the | response measured is going to be different. Dirac and manual | methods with REW use multiple points and/or just moving the | microphone around. | chamod12 wrote: | tomduncalf wrote: | Cool project! I recently bought a set of iLoud MTM monitor | speakers which come with a special mic which they use to analyse | the room and correct for it in a similar way to this. | | It makes a good difference to the sound - highly recommend the | speakers if you are looking for a smallish set of monitor | speakers that sound great and can be used very near field so you | can use lower volumes. | timc3 wrote: | Yeah, those are kinda cool. They have the added advantage that | they don't have a huge amount of bass, though what they do have | is impressive for their size to be fair. | | But because of their size they don't always activate room | acoustics in a crazy way, and a lot of people monitor with them | fairly close so don't need them loud either further lessening | the problems. | archi42 wrote: | > a lot of people monitor with them fairly close so don't | need them loud either further lessening the problems. | | This simple insight is gold. But is it actually true? The | standing wave should still pop up. Though with less energy | it's probably mostly handled by the furniture. | | Whatever the case, having monitor speakers sitting close | avoids/lessens the issue of the first reflection point, | making the higher bands sound much less "muddy". This can be | improved by picking a speaker with a strong beaming | characteristic. Eg 4" broadbands will bundle the acoustic | wave quite strongly in the higher frequencies. Sounds muffled | for bystanders outside the beam, but amazing stage and | resolution for the one or two persons inside of it. | anotheryou wrote: | I'm using the commercial https://www.sonarworks.com/soundid- | reference and it's amazing. | | I'd say the worse your setup (especially your room) the more | magic it does. | | I did it without an individually calibrated mic though (but with | a decent measuring one), wonder how much better it could be. | RedShift1 wrote: | Is it affordable for mortals or is this a business only | offering? | anotheryou wrote: | Certainly expensive. ~300 eur/usd with mic (and you need a | proper audio interface to support the mic). | | A bit sad, because it might do most for less expensive | speakers and untreated rooms. | timc3 wrote: | It's cheap compared to a Trinnov system. But honestly you | might be better off spending 300eur/usd on wood, Rockwool | and some fabric. | brandonmenc wrote: | I'm also using this. | | The results are very good. I have studio monitors and a crappy | room setup, and the calibrated sound is much better. I | purchased the kit with the supplied mic. | | That said, the software is unstable. To the point of | uselessness. It caused so many system crashes that I - very | sadly, because the results are so good - just don't use it | anymore. | | Hoping they fix stability in later versions so I can go back to | using it. | anotheryou wrote: | I think a lot happened shortly before the rebranding to " | _SoundID_ Reference ". If you tested before that, maybe give | it another go. | brandonmenc wrote: | I stopped using it about a week ago. | rcarmo wrote: | This is very nice. I also appreciate the pointers to various | equalizer apps in the README, I didn't know a couple of them. | dfbb wrote: | qbonnard wrote: | Newbie question: how do we know we can trust the microphone? | | It sounds like a chicken-and-egg problem to equalize speakers | with an equalized microphone, but maybe microphones are simpler | and can be assumed to be equalized ? | pier25 wrote: | There are cheap calibrated mics available. There's one for | about $20 from Dayton Audio. | AndrewUnmuted wrote: | tibbon wrote: | You'll need a calibration curve for the microphone. Even of the | same model, there is a lot of variance. | willis936 wrote: | Anyone interested in this area should also know that above ~2 | kHz it doesn't matter what you do for magnitude equalization | because you'll be dominated by sub mm variations in position | and direction. The only way to get any amount of | repeatability above 2 kHz is with IEMs. | erdewit wrote: | This is dealt with by smoothing the spectrum in a way to | preserves the power density. The constructive and | destructive interference then cancel each other out. | Gracana wrote: | What does "smoothing the spectrum" mean? What operations | are being performed? | danuker wrote: | I'd guess: Fourier transform, a power density preserving | blur convolution, then inverse Fourier transform. | | But I am not familiar with the field of signal | processing. | doctorhandshake wrote: | There's an example of doing this on the readme- scroll way | down | gh02t wrote: | MiniDSP makes some calibration mics that run about 60 bucks. | I used them as a cheap instrument for some lab work where I | needed a calibrated mic a while back and was very impressed | with their performance for the price. They ship with a little | code that you can use to retrieve the calibration curve from | the factory, and I know a lot of people use them for hifi | calibration with REW. | O__________O wrote: | Not an audiophile, but one way might be tuning forks. That | said, I would be super surprised if this was needed for high- | end microphones. | amluto wrote: | A microphone's ability to reliably identify a frequency is | excellent, even if the microphone is cheap, crappy and | uncalibrated. It's almost entirely a function of whatever | clock is used to digitize it, and oscillator chips that are | just fine are ubiquitous. | | The issue is calibrating the _amplitude_ response at a given | frequency, and a tuning fork won't help. | | edit: those quartz oscillator chips have a lot in common with | tuning forks. | Schroedingersat wrote: | A microphone that is linear to a dB or so is far cheaper than a | speaker that is linear to 6dB and room treatment that maintains | that. | hedgehog wrote: | This looks cool. I'm not sure if they are intending to go all the | way to room correction but it can really do wonders. A good while | back my music setup used filters calculated by an open source FIR | tool with playback driven by an older version of Shairport | (emulating an AirPort express) using BruteFIR as a convolver. | Fiddly to set up but it sounded really good. | | 1. http://drc-fir.sourceforge.net | | 2. https://github.com/mikebrady/shairport-sync | | 3. https://torger.se/anders/brutefir.html | strainer wrote: | I have made a small webtool to help calibrate various EQs by ear. | It kind-of mimics a graphic EQ in the browser which can also play | tones around the EQs frequency bands, which should sound about | the same loudness as their neighbors according to the ISO | loudness curve. I increase or decrease my laptops EQ bands until | the tones on the webtool play without obvious difference. This is | sure to be an unsatisfactory process for technical purposes, and | I couldn't even guarantee that I implemented the loudness curve | well, but I have a lot more success using it to help tune EQ than | without it. | | https://strainer.github.io/hearqualizer/ | etaioinshrdlu wrote: | I think it would be cool to make a more advanced version that | corrects for many types of nonlinearities: amplifier distortion | and mechanical parts resonating badly. | lvl102 wrote: | I highly suggest getting flat neutral speakers first. Preferably | high end studio monitors. What would be interesting is if someone | can work on music-specific optimization based on a handful of | inferences and ML. | timc3 wrote: | Nope, it's better to treat the room first, then invest in some | quality monitors like Neumanns. Basic budget monitors will do | great in treated room. | runeks wrote: | I've tried this for my speaker setup. And the problem is that the | frequency response is a function of volume. For example, the | louder I play music the more the bass is accentuated. I think | this is because of standing waves. | | So the problem I find is that when the volume is low the bass is | too low, and when the volume is high the bass is too loud. Only | when I play at the same volume as the equalization was performed | at do I get a good result. | fhchl wrote: | This is a common psycoacoustic effect and probably not due to | the loudspeakers or the room acoustics (which are linear): the | (perceived) loudness of a tone is frequency and level dependent | [1]. This makes sounds more bassy at large sound pressure | levels. | | [1]: https://en.wikipedia.org/wiki/Equal-loudness_contour | newaccount74 wrote: | Some hifi systems have a "loudness" setting that raises | bass+treble to compensate for this effect at low volume. | timc3 wrote: | This type of software, is just a bandaid and really doesn't work | very well (though it can work better with headphones). Properly | thought out and tuned acoustic work is what is needed. | | I am lucky enough to have a spare room in my house, and set out | to build a studio (an almost life-long dream) and decided that I | didn't want to compromise on the acoustics and spent some time | looking into the subject. In the end I built it myself with a | huge amount of acoustic treatment (lost a large amount of the | volume room), but more that that I enlisted the help of a | professional who could do the maths and help with not just the | trapping but also the panels that are needed. In the end after I | built it was also tuned with DSP by the professional, has what | you would normally call 4-way speakers with the subwoofers going | to a higher frequency than most would consider normal and even | the desk was specifically chosen to not cause a problem for the | listening environment. The difference between this and something | like Sonarworks (commercial software that I tried for a laugh | beforehand) cannot be overstated. It's basically flat between | 23hz (slightly rises at 20hz I believe) and 20Khz - we actually | tuned in a more natural response curve. | | It's still a home studio because it's in my home and I don't do | anything commercial with it, but it's pretty much mastering | grade, all with materials that are available in a builders yard | and the special sauce, someone that knew what they are doing. Not | everyone has the room or space to do this, but most people can | build some bass traps and something to tame first point | reflections. | danuker wrote: | This project still has a good bang for the time or money buck. | | Life has compromises. You do give up some things to build a | perfect studio. | solardev wrote: | Asking because I'm not smart enough: Is this kinda similar to | what the Sonos Trueplay feature does? (Where you move your phone, | and/or a mic-enabled speaker itself, around the room so that it | plays and measures various frequencies to calibrate) | | https://support.sonos.com/s/article/3251?language=en_US | | https://patents.google.com/patent/EP3531714A2/ | zihotki wrote: | That one is an automatic room equalization, it's different from | speaker equalization and it probably should be done after | speaker equalization. But it's more useful for the end user. | solardev wrote: | Sorry, I might've linked the wrong patent then. (I meant to, | but failed to, find the one that handles speaker equalization | for a single speaker). | | By room equalization, do you mean normalizing volumes between | different rooms, or...? | newaccount74 wrote: | Room equalisation is about counteracting the effect of the | room and the placement of the speakers. For example, when a | speaker is close to the wall, or in a corner, low | frequencies are amplified, even if the speaker on its own | has a flat response cureve, so you would reduce low | frequencies to adjust for the room. | patrakov wrote: | There is an older project with better math inside: http://drc- | fir.sourceforge.net/ | | For starters, it doesn't try to achieve a phase-neutral response, | because a phase-neutral response created in a room is only valid | in one point of the room, and creates pre-echo artifacts | elsewhere. In fact, it tries to separate the response of the | speaker itself from the response of the room, by setting a | threshold in the time domain, so that everything coming before it | must be unaffected by the room. Then, everything coming before | the threshold is corrected to a linear phase, while everything | else is corrected to the minimum phase (thus making the second | part of the filter purely causal). | | Also, they provide an argument, citing literature, that | equalizing to a flat frequency response would be wrong in a room, | and thus provide an option to remove excessive treble and achieve | a 1dB/octave roll-off. | | Please see the details at http://drc- | fir.sourceforge.net/doc/drc.html | erdewit wrote: | > because a phase-neutral response created in a room is only | valid in one point of the room | | Author here. The term "phase-neutral" simply means here that | the impulse response is symmetrical and doesn't add a phase | shift. It doesn't even try to neutralize the phase | characteristics of the room, which is what you may be thinking. | In fact the phase information from the measurement is | completely discarded. Furthermore, the frequency response is | averaged to get a more general and robust (less over-fitted) | correction that works pretty well across the room. Try it... | patrakov wrote: | Well, if you discard the phase of the original response | anyway, then you can shave a few milliseconds of latency by | switching to minimum-phase (which is causal, not symmetric) | instead of linear-phase. The math is in | scipy.signal.minimum_phase. | [deleted] ___________________________________________________________________ (page generated 2022-09-11 23:00 UTC)