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Show HN: I made a free app to calibrate your turntable by simply playing a song

grooved.okat.best

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Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#91

Post by jerf »

crazygringo wrote: post #26

This seems really clever -- kudos! 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 wel…

I would expect:

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.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#92

Post by virskyfan »

Great! In the past I've used the app that measures the turntable speed through its accelerometer...it's somewhat uncomfortable and weird to set the mobile on the turntable, start and stop once and again. Would love to see a comparison of measurements taken with your app and the one using the accelerometer...calibration is a huge thing in engineering.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#93

Post by okatbest »

plastic3169 wrote: post #42

Looks amazing and useful for me! The links don’t take me to the app store on my iphone and the app name is not in the heading I need to scroll past the copy to find what to search for. Minor annoyance but for some reason annoyed me a lot. That annoyance led me to hate the copy as I was searching for the app name and tried to skim the text. This is probably the first time I write any feedback to internet. I am usually…

Hey that's very odd, would you mind telling me which country/region you are located in?

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!

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#94

Post by okatbest »

thekegsi wrote: post #52

You can get apps where you place your phone on the turn table and it directly measures the turntable speed using either gyroscope or compass https://play.google.com/store/apps/details?id=com.vinylrpm&h...

This is how this project started! I thought I was super smart figuring out I could do that, then I realized there are many apps that already do the same thing. 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.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#95

Post by taylodl »

kevincox wrote: post #66
sambeau wrote: post #56

Earlier quoted context omitted.

>scratches meet the needle once per revolution, regardless of the needle's position I need to go away and think about that :D

The needle doesn't pass at a constant "ground speed" everywhere on the record. On the outside the needle "travels faster" and in theory you have more detail. Near the middle the needle travels over the record surface slower.

That's one of the reasons you'd put your best song on side A, song 1 and your 2nd best song on side B, song 1 - you got the most detail on the outside track. I remember seeing an interview with Led Zeppelin quite a few years back where they were claiming they knew they'd have a smash hit with Stairway to Heaven. Which was funny, because I remembered then seeing an interview several years before where they said it was a track they never thought was going to go anywhere.

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.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#96

Post by egypturnash »

taylodl wrote: post #90
egypturnash wrote: post #68

All the turntables in my life as a kid had built-in calibration, in the form of four rows of repeating black/silver squares on the side of the wheel, a light flickering at the mains frequency, and a little dial to adjust the turning speed until the row of squares corresponding to your current combination of 50/60 hz DC and 33/45 RPM appeared to stop moving. It was a very clever trick.

You had access to nicer turntables as a kid! That was a distinguishing feature between the more "serious" music hobbyist and the person who just wanted to play some tunes. 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 mar…

My dad was a recording engineer, so he knew where to go to find the sweet spot between "this sounds great" and "this sounds insanely fabulous but requires a second mortgage".

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.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#97

Post by okatbest »

virskyfan wrote: post #92

Great! In the past I've used the app that measures the turntable speed through its accelerometer...it's somewhat uncomfortable and weird to set the mobile on the turntable, start and stop once and again. Would love to see a comparison of measurements taken with your app and the one using the accelerometer...calibration is a huge thing in engineering.

I'm gonna be honest, using the accelerometer will definitely be more accurate because you can take more samples over a longer period of time. That's how this project started, but I also felt uncomfortable putting my brand new phone on a fragile player and even more so asking other people to do the same.

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.

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#98

Post by okatbest »

dmd wrote: post #76

I've tried this on a dozen or so records and all I get is "Please made sure your device can hear the music, and that you're using a modern song with a clearly defined beat." (There is definitely a very well defined beat.)

That's odd, could you share an example of a record you use? Are those fairly popular/common records?

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)

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#99

Post by [deleted] »

peter_l_downs wrote: post #49

Strongly recommend updating your website to lead with some variation of "This is an offline iPhone app to help you calibrate your turntable's speed, all you need to do is play your records and the app will show you the current RPM" — wayyyyyyy too many words and other nonsense before I could figure out this is what it did. Embed the demo video (the tweet you linked) too! Looks great and if I still used records I woul…

[deleted]

Re: Show HN: I made a free app to calibrate your turntable by simply playing a song

#100

Post by dmd »

okatbest wrote: post #98
dmd wrote: post #76

I've tried this on a dozen or so records and all I get is "Please made sure your device can hear the music, and that you're using a modern song with a clearly defined beat." (There is definitely a very well defined beat.)

That's odd, could you share an example of a record you use? Are those fairly popular/common records? 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)

I've tried the White Album, Tiffany (I think we're alone now), and a bunch of songs on Cake Comfort Eagle.

No, the disk is not moving at all! It's turned up pretty loud.

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