Show HN: I made a free app to calibrate your turntable by simply playing a song (grooved.okat.best)
I made a little app that lets you to calibrate your turntable by putting on any record and tapping a button. It's called Grooved and it uses your phone's microphone to see how fast your platter is going, almost like magic.
You can see what it looks like in action here: https://twitter.com/OKatBest/status/1795453042994680148
The app itself is free without ads, subscriptions, or trackers. It's a tool I built for myself, and I just thought someone else might want to use it too. I have never seen this technology being used before, all other apps require you to either print something and use the camera, or to place your phone on the spinning platter and use the accelerometer.
You can grab it on the App Store, and I am working on an Android version I hope to release at some point in June.
Would love to hear what you think about it!
Ivan_
238 comments
[ 7.6 ms ] story [ 275 ms ] threadHow frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?
Lots of turntables have variable speed, DJs can tell you more about it :)
> How frequently do the rates get out of sync? What causes it? Do they vary on an album by album basis?
When you're DJing, one of the main things you'd deal with, is making things be in sync, one way or another. I'm not sure how much value you'd get from an app like this that seems to be more "fire and forget" and not for on-the-fly matching.
I'm guessing this app is for people who do their own maintenance, repairs and such of turntables, so they can easily verify their work.
Plus DJ turntables tend to be direct drive, which should be pretty consistent. Where as consumer record players tend to be more belt drives. And I’m assuming those belts can stretch with time?
I agree :)
> Plus DJ turntables tend to be direct drive, which should be pretty consistent
Indeed, but once you start doing repairs and/or modifications, things can get fuzzy. Maybe the app would help those people?
Audioplebs need not apply.
Most record players are belt drive. Anything that is belt drive usually has some slip / variation (if more familiar to you, imagine the belt drive on a lawn tractor). Many have a finer adjustment to tune the spin rate. +- off of the selected rate. (Perhaps you selected 33 rpm but it’s really spinning at 32)
I’m sure someone who knows much more then I do, could give a much better explanation along with other types of tuning. (Arm weights, needles, etc etc)
I only commonly use a dual 1219, dual 1229, (both purchased for under $30), and a victor victrola from 1908 so my knowledge is severely limited despite having played with others it’s focused on those units.
Rates will be off due to manufacturing tolerance or mechanical wear (i.e. a loose belt slipping on a motor).
Most people don't worry about it.
It doesn't really vary album-to-album, unless you have some ridiculously heavy records that slow the motor.
Belts age. Friction within the motor and the table's bearing will change over time. It is not necessarily a frequent thing that needs to be done, but usually the speed will change slightly over the life of the table.
Good players will have it on the front, and will have a strobe to help you adjust that (the little dots you see on the outside of the platter on fancy players). However, cheaper players may not have an easy way to adjust, and some (like mine) hide the knob under so it's a pain to adjust.
Cheaper players are more likely to come misconfigured from the factory. I asked a lot of friends (who are amateurs, not audiophiles) to test this app out and every single one had a turntable that required adjustment. Mine's running at 34.6 RPM which is just 3% off, but when listening to my favorite albums I can definitely tell that it's too fast and too high pitched.
The speed will also sometimes drift slowly over time, which is why it took me a while to notice my table was off.
If you have a turntable, you can try listening to the same song from a record and from a digital release, and see if you can hear a difference. If you do, I know just the app for you!
Still pretty cool for those that need to calibrate a turntable, or verify 33 vs 45 PRM for a record.
I'm really really curious how this is done now...
> Grooved does not collect any data, whatsoever. The audio stream is processed locally on your device and never recorded.
Which is consistent with how ShazamKit works [0]:
> Audio is not shared with Apple and audio signatures cannot be inverted, ensuring content remains secure and private.
0: https://developer.apple.com/shazamkit/
0: https://developer.apple.com/documentation/shazamkit/shmatche...
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Cool app and thanks for sharing! :D
update: youtube to the rescue. pretty common affordable turntable( Audio-Technica LP60), so I figure I would put the vid link here for others who might want to know - https://www.youtube.com/watch?v=d3PdS2V8Jz0
This is exactly what I hoped for when building this app. Making a dead simple tool for people who want their records to sound better, but may not have the equipment or knowledge necessary to adjust it.
It's between 59 and 60 cents: more than a quarter semitone.
Exact value:
So 59.6 to 3 sig figs. Someone with a good pitch memory of a tune (hearing in their head how it should sound) would spot such a difference. Especially if they heard the tune recently.When using digital mastering, you can also adjust the playback speed, but you can correct the shift. You get more "liveliness" without the shift change. That's why you're not hearing the pitch shift so much in more recent music.
Free and open-source.
https://www.youtube.com/watch?v=TE3pgOkfYu0
In that case, it's a pure stretch: i.e. the tempo is slowed down by a factor of 0.996 to achieve the pitch change.
I also have an unpublished version of that track transposed from the key of Em to Dm; that was a pitch change preserving tempo.
When you need to pay attention to anything outside of open string, fretted 12th, open harmonic 12th fret (and fretted 24th if you have a 24+ fret guitar) for intonation, it's time to get the guitar to a luthier for setup maintenance. Something else is drastically wrong in the setup.
As I'm writing this I'm thinking to myself I know there are AI tools now that can take any track and produce all the stems for all the different parts in the track. You'd think for something like the lead guitar they could analyze that stem and produce either the tablature or standard music notation for the solo. That would be kinda awesome! I wonder if such a tool now exists?
Lisp-wise:
So, it is a .0578 percent change in pitch, or determiner of pitch like record rotations speed.Musically, two notes an octave apart vary by a factor of 2 (e.g. Middle A (A4) is 440Hz and the next A (A5) is 880Hz), and our ears hear frequencies logarithmically rather than linearly, so each of the 12 semitones in an octave is a factor of 2^(1/12) higher than the previous one (so that 12 of them in a row result in doubling the frequency), and therefore the 100 cents between each semitone are each (2^(1/12))^100 = 2^(1/1200) greater than the previous one.
In can drive you nuts when you're playing by ear because when trying to find the root note, i.e. the key, you'll find it between two semitones. Always go for the lower tone. For example, if it sounds like it's a little sharper than A, but it's definitely not Bb, then you know it was A and the mastering was sped up. That's another thing, in my experience it's always sped up and never slowed down.
I have a theory that one of the reasons Eb standard guitar tuning started becoming so popular in the late 60s and into the 70s was because the speed up was getting to be so common that guitar players started adjusting their tuning for it, not to mention you generally get a "heavier" sound.
I'm glad it didn't continue with where you'll sleep tonight :)
I have a sense of tone and it's always seemed fine to me.
NTSC —> PAL can either be annoying, or difficult to manage without artifacts. If the NTSC source is telecined from a 23.976 source, you can invert that process to get the original back, and then deal with the minor time shift to PAL. If it’s pure NTSC, there’s a lot of filtering to be done to get an acceptable result. At least, last I played with it.
https://twitter.com/OKatBest/status/1795453042994680148
Then listen to the original:
https://www.youtube.com/watch?v=9NplyW8TF18
Maybe it's just me, but as soon as the guitar starts I can tell it's way too high pitched.
I'm curious how it actually works?
At first I assumed you were comparing the vinyl track to the reference digital track from some streaming service and either analyzing the frequencies with FFT or the timing of peaks.
But I watched your demo video and you don't need to tell it anything about the song.
Which makes me think you're rather doing an FFT and simply trying to match how well the frequencies align to the well-tempered scale based on A 440 hZ.
Which then leads me to three questions:
1) Obviously this wouldn't work if you were playing a standup comedy album or something? Or the drum solo part of a song?
2) Are essentially all albums perfectly in tune with A 440 hZ? For example with classical music, I understand that 442 is also used, baroque is sometimes at 415, and 432 has been common as well? I don't know about pop but I can't help but wonder if some artists have intentionally chosen something other than 440 over the decades.
3) I assume this won't work if the turntable speed is off by more than 2.8%? Since the distance from A4 (440 hZ) to A-flat-4 (415.30 hZ) is a decrease of 5.6%, and so if the turntable is off by more than half of that you'd be trying to align to the wrong note?
No they are not all tuned to 440Hz. This is really evident if you play an instrument and want to play along with an album.
I need to go away and think about that :D
Which is it? It's track position - 4th track on the A side, i.e. the last track, tells you how important they thought it was. Which is to say, it was a "throwaway" track that made it big. It happens.
The other odd thing about that album is "When the Levee Breaks" is considered to be the 2nd-most popular song off of the album and it too was the last track on the B side.
What this tells me is the album's producer, one Jimmy Page, was out of touch with what Led Zeppelin fans liked most. Based off the sound of the next album, Houses of the Holy, I'd say Mr. Page got the message loud and clear.
Those are two examples off the top of my head. If you give me a bit of time to put my kid to bed, I’m sure that I’ll find many more.
My guess would be some filtering (to remove the actual music) and some kind of autocorrelation algorithm to detect some periodic patterns with a period matching the expected rotation speed of a record within a few percent (33.3 RPM, it doesn't talk about 45/78).
They do say that the audio is processed locally, but that does not preclude them from making an API call to find a signature match.
> The audio stream is processed locally on your device and never recorded.
But you can also extract BPM info and compare that to a set of quantized reference BPMs that anyone would ever bother to use.
And also, since you’re getting multiple pitches from multiple instruments in a time series, if you can isolate particular instruments, you can calculate the key the melody and/or harmony of the song is in.
Then, you could either come up with a heuristic, or just train a Bayesian filter, using datasets of “real” and “erroneous” (key, BPM) pairs.
And more specifically, to address your question, I don't know enough about the recording part of music production to say whether most performers get a click-track played into their monitors or not. (I know that I've seen at least some performers using click-tracks for studio recording; but I'm not sure if that's only given if they ask for it, or if it's the studio pushing it on performer to make their jobs easier. I imagine click-tracks would always be used for multi-performer async studio recording — as otherwise you'd have performances that have conflicting BPM. But maybe not for single-performer pop/EDM songs, where it's just a vocalist laying down a track, and then everything else is done in software?)
The evidence I can cite, is from the outcome of the production process: I have a strong recollection from back in the late 2000s, of using some music library auto-tagging software that would, among other things, analyze the BPM of a song to populate the BPM ID3 field of MP3s. For at least the music I loaded into it, BPM did appear to be (mostly) quantized to nice, round numbers. (And it wasn't just the software being coarse-grained in its estimates; it did give weird numbers for unusually-produced songs.)
I do know that for any modern "produced" music (i.e. music not recorded as a live ensemble session), even if the performers did lay down their tracks at a weird BPM, the audio engineer is still going to be throwing their performances as separate tracks into a DAW. And one of the things you tell a DAW, when creating a project, is the BPM — which creates a grid of bars that tracks/samples want to snap onto. Even if you're not trimming or speed-adjusting performances so as to snap the ends of each track/sample to the DAW's grid, you're still likely snapping the beginning of each track/sample to the grid — you'd have to fight the DAW to not. Which means that, by default, if the song is "produced" enough — tracks cut up and slid around, reused, etc — then the output of this moving-and-snapping process will be a song that reads as the project's BPM.
Separately, I know that people learning to play an instrument for classical/orchestra music, often practice their instrument using a metronome (at least at the early levels.) Which perhaps gives at least some of those people the speed equivalent of perfect pitch — the ability to "lock into" certain BPMs; and to know if other performers are running fast/slow vs the "expected" BPM of the song.
I would assume that even for rock performers with no classical training, the early-level "textbook" practice for drummers and rhythm guitarists also involves playing with a metronome. It might be a lot more tenable to play a rock song at e.g. 117BPM, if everyone's just playing on the down-beat of the drums; but these performers still don't want to have a sudden, unintended shift in their BPM due to not being able to do a drum fill / complex chord change quickly enough; nor to start rushing as the song amps up, forcing everyone else into increasingly-stressful playing. In doing drills with a metronome to keep their BPM constant, these performers are likely implicitly learning to lock into certain specific BPMs as well.
My impression is that the one case where this probably isn't true, is in live jazz performance, and more specifically in live jazz improv "jam sessions." In those, the percussion (if any) isn't driving the performance, but rather is just another component of the harmony, following the (often wavering!) BPM of the lead performer.
(Is this why the classic meme of classically-trained performers not getting along with jazz artists? Because the jazz artists won'...
I think you’re getting tempo, pitch and time signature mixed up. Jazz musicians are excellent at staying on tempo. Staying on tempo is so important in jazz that when I was young, we had to earn the right to practice without a metronome. At the highest levels, jazz can be mixed with jazz because the tempo is solid enough.
Jazz though uses some time signatures that are hard to visualize. Once you’ve played them for long enough they become second nature but they’re likely the hardest part of learning to play jazz. Those time signatures are also common in classical music. Getting time signatures mixed up can sound absolutely awful and that’s a hard thing to fix on the fly unless you know the musicians extremely well (though then the odds of playing the wrong time signature are quite low). Learning to improvise is an entirely different can of poisonous snakes but in an ideal setting you wouldn’t start improvising until you can play.
Pitch can be a problem, but it’s easy to hear and correct on the fly.
As for classical and jazz musicians getting along or not, when I grew up the usual transition was classical to jazz. When jazz was first being invented, there were some racial issues between (generally Black) jazzbos and classical heads. But when I was growing up, we were all band geeks and had a lot of mutual respect for each other.
One thing I’ll note though is that music communities (much like software communities) can seem very toxic to outsiders. If you want to get good, you learn to take and give very direct feedback. It’s a problem when you have a very gifted musician playing with beginners, but amongst musicians of the same calibre, it’s a really warm, loving feeling.
Wrong, drums (or the bass) most usually is driving the rhythm, and jazz musicians are extremely adept at staying on tempo.
> Because the jazz artists won't stay on beat, and this irritates some perfect-pitch-like "out of tune" feeling in the classical musician?)
Try the exact opposite. https://www.youtube.com/watch?v=rEbUNDW9bDA
> you'd have to fight the DAW to not.
That's just outright false. This is a basic action in all commonly used DAWs. eg https://promixacademy.com/blog/how-to-nudge-tracks-in-logic-...
[0] https://www.npr.org/2024/04/09/1243632570/chechnya-music-ban...
[1] https://www.youtube.com/watch?v=Q811R6YsM0s
Not everything is recorded with a click track, though a lot is.
But even so, while it will usually be an integer BPM, it's not always rounded to the nearest 5. 120 might be too fast while 115 is too slow, so you pick 118.
For an app that's trying to correct your turntable speed by e.g. 3%, it couldn't even begin to guess the "correct" BPM.
If so, then that could still be how it was done here. It wouldn't always work for the first record, but you'd be highly likely to get a "good reading" by at least the third one you try.
https://assets-global.website-files.com/6188e55dd468b56ab674...
from:
https://blog.musiio.com/posts/which-musical-tempos-are-peopl...
There are plenty of songs ending in every integer.
A very simple idea, as all the best ideas are.
1. Detect wow: https://www.youtube.com/watch?v=kCwRdrFtJuE
2. Time wow.
3. Round to nearest record speed and report delta.
I'd also expect that armed with a normal FFT algorithm that Ye Olde Bash On Algorithme Until Functionale would be fairly likely to work with reasonable effort, without having to get too "signal processor-y" on the FFT output.
If you were using an LP with a known pure 440 hZ sine wave that you could lock onto exactly, then sure. That's kind of how frequency modulation -- FM radio -- works.
But I really don't see how you could do this with songs that are full of frequencies coming in and out and changing all over the place. If you analyzed the full side of the LP, you could probably get enough signal out of that.
But trying to measure the precise wavelength of wow when you're only getting a few wavelengths' worth, from a complex signal? I don't see how.
For ex, I would bet that 2x intended speed isn’t simply 2x every frequency in the FFT, when played through vinyl on a physical turntable.
Maybe some collection of distortion signals based on disk manufacturing and turntable manufacturing.
I am much less confident about my claims that it is something you could bash together in "normal code" from an FFT, without advanced math, but it still seems likely to me. You have huge stonking correlations between the frequencies you can exploit. Imagine a normal FFT chart like you've seen any number of times. Now, take that same thing and wave it up and down quite visibly on a sine wave. Nice and big in your imagination so you can see it. You think that's not something that could be picked up? Now, scaling it down to where you can't hear it anymore may make it harder to believe, but the same code will pick it up. To a computer it would still be clear as day. This is one of those things microphones pick up much, much better than human ears, just like microphones trivially pick up a quite 1001Hz tone next to a loud 1000Hz tone even though we can't hear it at all.
Compared to, say, recognizing a voice and extracting words from it, this is pretty trivial stuff.
That's where you're wrong. FFT frequency bands are surprisingly wide. You can make them narrower but with the tradeoff of losing temporal resolution. And it gets worse the lower the frequency gets.
There is absolutely no way you're going to detect a near-0.555 hZ effect from a few seconds of audio and determine whether it's off the frequency by 0.1% or even 1%.
Like I said, sure if you're dealing with a pure sine wave. But not a complex signal using FFT.
Or to put it another way -- a 1,000 hZ signal? Absolutely. But a 0.5 hZ signal? Absolutely not.
But it still sounds very challenging: there's multiple sources of periodic frequency change both in recordings and in playback mechanisms.
Two common algorithms are cepstrum and analysis, and auto-correlation, which involve taking the DFT or inverse DFT of the absolute value of the DFT of the signal.
Find the peaks of the result, and then fit a cubic polynomial to the the peak, and the bins on either side, and then calculate the maximum value of the polynomial. The value at the which the maximum occurs determines the inverse frequency, which can then be converted to pitch.
Both algorithms produce results that are accurate to less than 0.1 cents. You do have to tweak buffer sizes and windowing depending on what pitch ranges you are interested in, and do some post filtering to skip over transients.
The temporal resolution problem is solved by calculating the result on overlapping frames. .
You simply can't detect an inaudible-to-human-ears 0.5 hZ signal from 3 or 5 seconds of complex normal-volume audio, down to the accuracy of cents, much less 0.1 cents.
As I said above: a 1,000 hZ signal? Absolutely. But a 0.5 hZ signal? Absolutely not. There just isn't enough signal for that level of precision. No matter what tool you're using.
My suspicion is that OP assumed that the source material was accurately tuned to A=440, which is not a safe assumption, but is probably true for any source material that has a keyboard instrument which will almost always be tuned to A=440. Calculate the reference pitch for the source material, and you can tell how much the speed of the turntable is off. (And as others have pointed out, may be completely buggered by common mastering practices, and by Original Instrument recordings of classical music using pitch references other than A=440).
But it doesn't seem implausible that you could use analysis of wow in the source signal too.
1) It actually might! Worth a shot I guess, but I don't have any comedy albums to try it out. I was able to get drum solos working fine
2) Was answered better by somebody else
3) I was able to get it to detect speed issues up to 9% off, beyond that it just stops working completely. Though that was in controlled environment so YMMV. If you see the sample vid I posted above, my player is roughly 4% off which is a lot but I genuinely believe a whole lot of people wouldn't notice that
Is this the aforementioned comment about _why_ you aren't being specific about the implementation?
> Eventually I decided to see if I could find a novel, more user-friendly approach that doesn't require you to put a thousand-dollars phone on a fast moving spinning thingie, and that's how Grooved came to be.
If it isn't then I couldn't find it. I was very curious about that too (both how it worked, and then the incentive for secrecy--totally your prerogative but again curious given the veiled-to-me explanation) but didn't seem to find such a comment. Protecting novelty seems like the implied reason.
Essentially I don't want to have somebody swoop in, replicate the same thing, be better at marketing, and charge money for it. I'm both protecting users because they shouldn't be charged for something that is free, but also protecting my ego because I spent time and effort and as far as I can tell I'm the first one to build an app that works this way and it sucks when somebody takes a community thing and paywalls it.
Once the Android version is out and everything blows over I might consider making the apps open-source so that anyone can see and learn how it works, then potentially make derivative works.
But in your case you don't plan on monetizing, so why iPhone first?
I appreciate the fact that they're developing an Android version at all, because this sounds simple and useful for me!
What it came down to is that I use an iPhone as my daily driver, and when I pulled my Android test device out of a drawer the battery was twice the size so I immediately brought it to an electronics recycling center.
Which means that in order to complete the Android version, I need to shell out $400 for a new phone I'm only gonna use once for a non-commercial project. So my idea was, let's release iOS first, see if people care, and then I'll spend the remaining time and money to finish up the Android build!
I think if I did try to finish Android at the same time, I would have given up on both and released nothing.
I've developed for both as well and would say getting _started_ with iOS development is about 10x more time consuming and complicated than Android -- or at least it was about 8 years ago.
I know you know this, but you don't need to own an Android phone to develop for Android (and you don't have to spend anywhere near $400 on one if you do want one).
Looks like it'll be a pretty great app and hope you do manage to get the Android version up and running.
I found the copy on the site a bit gross - I'm not sure something like this needs a critique of modern copywriting, and for me it gives that same weird sense of over familiarity ('we get you') that I think it's trying to criticise.
The gyroscope on your phone is accurate enough to measure RPM to about the first decimal place at 33 1/3 - 45 rpm's just by placing your phone on the turntable flat and letting it spin.
P.S. Reading comments from a bunch of tech folks trying to wrap their heads around an app for calibrating analogue music playback device is very amusing. :-)
I actually released the app yesterday but didn't post about it til today because it wasn't being indexed properly on the App Store yet, it's possible that it's still not live everywhere. I have an image link to the listing in the first section of the web page and if on iPhone it should show you the classic "this website has an app" banner at the top.
If you're searching for it, "Grooved" has many results but if you accept the suggestion of "Grooved: turntable calibration" it'll come up.
This is a direct link to the store page: https://apps.apple.com/app/grooved-turntable-calibration/id6... Please let me know if it still doesn't work and I can take a look... Thanks!
Is this zeroing in on traces of 60 cycle hum in the recording?
Or else, won't it adjust an out-of-tune song to be in concert pitch? (Mind you, that would be extremely useful if you're playing along with the track and don't want to adjust your instrument, or cannot do so.)
To get it to the correct speed, I would go through my record collection and find a tune with long, sustained notes. Find the same tune on Youtube and get a pitch reference for the note using a digital tuner. Then adjust the record player to match the pitch on that note, down to 1/10 of a Hz precision.
(In the first place, why would you have a record player without a built-in strobe light for adjusting the speed in 2024, when this was a common item even in lower income households in 1984.)
Also west Japan is 50, east 60.
The main problem is: (1) there isn't a lot of hum on professionally produced records; (2) but there may be hum from the equpiment itself.
As for being skeptical, good! That means I'm doing something great according to Clarke's third law.
You can see me testing out the app on multiple records here: https://twitter.com/OKatBest/status/1795453042994680148
The results aren't 100% perfect, and they definitely won't be as good as matching specific frequencies, but it'll get you very close to the ideal RPM.
The idea is that the LED reaches peak brightness (and darkness) at twice the line frequency, just as ye olde fluorescent tubes did. (Or: Skip the extra diodes and have it work at 1x line frequency. I'm not your boss.)
After that, just print a strobe disc and use it.
But little neons are getting scarce (they aren't dear -- they're just much, much less common than they used to be). And working fluorescents (with magnetic ballasts that actually run at line frequency) are pretty much that way are too.
LEDs and resistors, though? Bright, cheaper than chips, and ready for all kinds of modern digital shenanigans.
Embed the demo video (the tweet you linked) too!
Looks great and if I still used records I would try it out! Congratulations on the launch.
EDIT: keep the rest of the writing if you'd like, I have no objection to it and I thought it was funny. But lead with what the app is and what it does!
I'd personally move that way up. I had to scroll across all sorts of fluff and effects. I was sold by this (edit: this chapter, not the fluff)
Maybe I'd personally even research how to make the entire website just that. Where maybe step 0 is "install the app" :D
The (promised) simplicity of the app doesn't show in the communication of the website at least.
I'll definitely be trying this out on my decks before my next set :)
Also hi joe :^)
It's intentional. The app is free. There is a statement about this whole corp mission mindset.
This is the way it is. If people don't like it or push it away from the product, they are not the target audience.
I think this is brilliant. I understood immediately what the app does and kudos for the courage in setting the website the way it is. Was also impressed with the aesthetic of the site.
If only I had a turntable...
> Would love to hear what you think about it!
Overall, my assumption is that by the time you make it to the website, you'll already know what the app does, and most people will link to the App Store directly (which is why the store listing is much clearer on what the app is/does). if not, my second assumption is that people will scroll right past that giant block of text and go to the last line which does explain what the app is in one sentence, because there isn't much more to say about it in my opinion.
If I made money off of the app I'd have a widely different approach, but in this case all I get paid with is strangers' attention and it is _very_ funny to me to spend that attention on a useless 2AM irrelevant tirade.
I have an Android so I can't try this out, as its in 'private beta' on Android currently.
Would love to see this as a open source project that I can install on Windows or Linux though.
I have considered making this app open source, and it may still happen in the future, but I do want to release the Android version first. I'm worried that somebody will see my code, repackage it with a new name, beat me with better SEO (which would be easy considering how dumb the copy is on my website) and sell it for profit before I have a chance to reach a wider audience. This is something that did happen with Boop, not a hypothetical.
The reality is that this app cannot collect anything valuable either way. It's a simple serving app that only uses your microphone for a couple of seconds at a time, and I assume most people will delete it once it serves its purpose. If I wanted to monetize it, the best way would be to add a "Pro" version with a subscription or to add ads, but I have no interest in doing either. This is a fun side project/portfolio piece, and I'd rather collect internet love distributing a ton of free copies, rather than sell a small fraction of that number of paid copies for $0.99 and have to deal with things like marketing, taxes, and customer support.
I use it and it's very handy. Thanks for creating useful no-nonsense tools!
But you're not worried that HN folks might run the app through a decompiler and find something approximately as revealing as your source code would be? The results might not be ideal depending on how much obfuscation you use, but I think it would be enough for someone to get the gist of how to replicate.
The important part is the rest of that sentence, I have an issue with people who steal the code (or concepts) and charge money for it. If I do end up open-sourcing the code later, people will see the code and I have no issue with that.
I suggest considering writing about it. Maybe a whitepaper? A publication? A patent application? May be colab with audio researchers? Or get sponsored from an audiophile record player manufacturer?
Just thought they were some funny aesthetic choice from the 70's and 80's.
Thanks for giving me the definitive answer for something that has always seemed odd to me.
I haven't messed around with a turntable in over 20 years but these days, only the supposed "serious" music hobbyist would be using a turntable and I'd think anyone making a turntable that didn't have this adjustment would be laughed out of the market. What are you going to tell me next - they're also using belt drive, a plastic needle, and a tone arm with a non-adjustable counterweight?! :)
And yeah honestly I'm surprised you can get a turntable that isn't made for the audiophile market any more, but the one shown in the video for this app sure does lack any fine speed adjustment. Just a little button labeled 33/45.
It's because of the other re-emerged market for vinyl: the "not-so-enthusiastic" collectors, who just want the album "on vinyl" to say they have the album "on vinyl" or maybe "in every possible format"; or because they love the band and the vinyl is just what you happen to get when you buy the special collector's edition box-set; or because they want to display the vinyl album cover somewhere visible in their house as if it were a poster print; or because they consider "a vinyl collection" to be an aesthetic decor item, like some people consider a full bookshelf to be an aesthetic decor item.
A lot of these are people in their teens/20s who don't actually think that vinyl sounds better, so don't have much enthusiasm for actually listening to the vinyl release (as they're mostly buying new vinyl, and these tend to come with a code for a digital copy as well.) So if they bother to buy a turntable, it's the $30 one they say at Urban Outfitters. They know they're just listening to the vinyl as a novelty experience, something they're only going to be doing a few times — and so they don't want to waste too much money on it.
(There is definitely a very well defined beat.)
Also, do you see the little disk outline moving during the analysis? This would confirm that your phone can hear the sound coming out of your record player (just to be safe: you need to play the song out loud)
No, the disk is not moving at all! It's turned up pretty loud.
If you don't mind, do you have any special setting on? Lockdown mode or something? Are you able to play the music back if you use the Voice Memo app to record a bit of it?
Sorry about all that, hopefully we can figure out what's wrong!
> Lockdown Mode is an optional, extreme protection that’s designed for the very few individuals who, because of who they are or what they do, might be personally targeted by some of the most sophisticated digital threats.
https://support.apple.com/en-us/105120
I'm concerned that the app does not work at all in airplane mode - like, even navigating between pages ("return to home" from a failure).
It also doesn't work (even without airplane mode) for songs that Shazam fails on - so I guess we've confirmed that that's how this works!
I'm not in the intended audience as I don't have a turntable, but if I had one I feel like I would be much more likely to use this if it was a web app. If I didn't know about this app beforehand, I'm pretty sure I'd be looking on Google rather than the App Store.
That being said, you made this app for yourself and it looks great. Congrats on shipping!
Grooved is still very accurate, especially if you run multiple measurements to confirm on multiple songs/records. The threshold for "perfection" in the app is 0.01%, which to me anything beyond that is a rounding error and I could not tell the difference in my tests. This is equal to a drift of about a third of a second over an hour of listening.