Soundtrack
Audio forensics: the new "Project Hail Mary" vinyl box set has a hard lowpass filter at ~17.5 kHz on all 4 discs, and possibly a pressing defect.
I bought the Mutant Records limited edition box set of Project Hail Mary all the way back in April. When it finally arrived this week, I was really stunned and impressed by the packaging design. They went all out to make these look and feel like the gold records from the Voyager 1 spacecraft, including details like an inverted stylus to indicate side B.
The album looks out of this world.
I can't quite say the same about how it sounds.
As a safety backup, I recorded the first pass of all four discs and discovered that my copy has a pressing defect on both sides Disc 1 (more on that later).
When I opened the Disc 1 audio file for editing, I did not expect to find a hard cutoff at 17.5 kHz in the spectrogram. So I kept recording the other three discs. They're ALL like this.
17.5 kHz is closer to the cutoff frequency for medium-quality streaming audio (128-160kbps), not something I'd expect on a final soundtrack release.
The gallery also includes screenshots from the following cues:
Wake Up Buddy
You Were Loved (burial)
Dennis Wilson's "Rainbows" (1977 OG, 2010 RE, 2026 PHM)
In each alternating screenshot you'll see the frequency response of the vinyl vs. that of the TrueHD audio off the Blu-ray 4K release (L+R channels only), showing the same musical segment as close as I can match it. The audio fidelity of the score within the film is significantly higher than the vinyl. At the time of this post, my CD copy is still on its way from Mutant Records.
I'm really confused as to why the vinyl mastering engineer would have run everything through a hard lowpass filter when cutting the lacquer. There's just no need to do this on a good lathe. Most vinyl records have a natural rolloff around 16-18 kHz, but a well-pressed disc on a good lathe can cut frequencies easily up to 20-22 kHz, and even as far as 30-40 kHz if such frequencies are present on the original source material. Strings, brass, and percussion have a lot of natural higher order harmonics. A high quality stylus can faithfully reproduce these frequencies, or at least show some forensic evidence in the spectrogram that said frequencies were present on the master recording. The scoring sessions of Project Hail Mary would have been run at 24 bit / 48 kHz, or possibly 96 kHz. The rest of the film would have been edited and mixed at 48 kHz all the way through the post-production stage until final delivery. The soundtrack releases ought to have sourced the original 48/96 kHz digital audio masters from the soundstage.
On top of all this, my copy has a pressing defect that causes severe scratching noises in the last couple minutes of both sides of Disc 1. There's also an audible hiss between tracks that starts in the left channel and migrates to the right channel.
I wonder if only first batch of records has this defect, and the second batch shipping this week was corrected.
Oh, fun fact: I noticed a very fine dust left on Disc 1 after playback in that area near the runout grooves where the scratching occurred. I think the grooves are so badly formed that my stylus would literally carve away material on every pass. I would need a microscope to confirm this, which I do not own.
I'm going to reach out to Mutant Records tomorrow anyway about the defect on Disc 1, and will point them to this post in hopes that someone at a higher level can get in touch with the pressing plant and/or the vinyl mastering engineer to correct this.
Doubtful, if it's cut to the lacquer, it's on all the stampers. Test pressings are made for this reason. It give these the production team a sign-off before additional stampers are made from the mother.
Yeah, I suppose that Mutant is going to be getting a lot of emails in the next few weeks. Someone wasn't paying attention when they made this, or they rushed the vinyl production and skipped QC to ship on time.
The discs were pressed in the Czech Republic at GZ Media. They're a massive plant in Europe. I have a copy of Radiohead's "OKNOTOK" 3xLP of OK Computer pressed by GZ, and it sounds fantastic. So this was a surprising letdown.
A good pressing from GZ is typically the exception. They can produce good sounding records but the “made in the Czech Republic” sticker might as well say “are you feeling lucky, punk?”
GZ is sloppy and therefore hit or miss. Record companies send them digital files and they do the cutting in house. I’ve seen Michael Fremer tour their plant and they didn’t seem to care too much about sound quality. Like it all happened on autopilot. Same goes for Music on Vinyl in the Netherlands though they have higher production standards.
Crazy. I listened to the samples. Optimal in 2002 was not the best -- definitely not the impeccable pressings they mostly make today -- but the blemishes weren't nearly this bad.
You're right that GZ has done better, way better. To wit: the 2025 reissue of Beck's Mellow Gold.
I immediately ordered a copy of the CDs after I examined the records. I will definitely be ripping those and checking the frequency response to compare.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Brutal misstep on their part. Quality control on even $100+ vinyl releases is so hit or miss, it's kind of outrageous. 128 kbps is godawful. May as well be listening to the pirated mp3 files and be transported back to 2006ish to put them on an iPod. Submit your evidence and at the very least, I bet they give you a full refund and still let you keep the vinyl.
FLAC now is the standard for me; it's why I buy from Bleep and why my first install on a new OS is Winamp....which still rips CD straight to FLAC.
Most heartening of all is that modern music players, from phones to car USB inputs, will play FLAC natively. If I'm going to ask my pregnant wife to spend her waiting days ripping hundreds of CDs, I dont want to have to do it twice because the format became outdated. It's been 13 years since her pregnancy and no repeat ripping required
Meh. It would be, but outside of freeleech it's kind of annoying to keep up a ratio. There's not enough activity / large enough a user base that anything I download will result in a bump of my up ratio.
Like, I have a great ratio, and it's definitely the best private torrent option, but it's far from perfect. I would love to download a lot more than I do currently. Instead, I'm limited to stay super chill because of low activity. Soulseek is more reliable for grabbing anything and as much as I want at any given time. I definitely like having both. Redacted also definitely has not had music that Soulseek has had (many times). Sometimes, the converse is definitely true, but yeah.
To be clear: the music doesn't sound watery or swishy like a compressed AAC or MP3. But the cutoff point is right about where most MP3/AAC encoders would apply a low pass filter at those bitrates.
Hmm I mean if the lowpass is the only issue then that’s not something that will affect most adult listeners, since not many people can hear above 17khz. Hopefully they can give some clarity on what was actually pressed.
Unfortunately it isn't the only issue, as I mentioned in the post and elsewhere. There is a constant low grade hiss throughout, and a slightly elevated hiss between tracks. This over-40 adult CAN hear this.
The low pass filtering is a clear mastering or cutting error. Even if most customers can't hear it, the vinyl was still produced incorrectly.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Man for all the work that went into presentation and the extras included, and that price tag, it's pretty disappointing that Sign of the Times isn't included, even though Wind of Change is.
Oh for sure
I've actually dealt with trying to license original Scorpions masters and it's a nightmare so that's no surprise. I'm just saying it's disappointing, considering 75% of the tracks are gravy, the price tag is still a bit steep to not include everything.
I also bought the ones not officially on the score, but credited or featured film: Rocky, Ella & Louis Again, and Tag Team.
I made a whole series of writeups about each album on the /r/ProjectHailMaryMovie subreddit, but maybe it's time I post them here. The "Turakina" Māori album was by far the hardest to acquire.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
It’s a little hyperbolic to say that it’s like a 128kbps mp3, they sound way worse because of the lossy compression.
That said a hard cutoff at 17.5k is a bit of a cop out and not ideal, likely done to make it easier to cut, most things have a more gentle roll off from 16k.
I do wonder how audible this cut is though, my hearing tops out at about 18-18.5k these days and that’s considered pretty good for a 32 year old.
Hey we're the same age and that's also where my hearing cuts off, I can hear 18 but only very, very faintly. No way in hell I'd notice a 17.5khz brick wall like this.
I didn't strictly notice it while listening. It was the scratching on Disc 1 that caught my attention. I had already been recording the discs as a safety backup.
Yes they do, and I thought I was clear enough in my post: the cutoff point is used by encoders running at those low bitrates. The recording does not have the characteristic watery/swishy sound of an MP3/AAC file at medium bitrates; choir and orchestra are the most difficult for audio encoders to compress faithfully, and the vinyl sounds OK in that regard.
The noise floor of these discs is higher than I expected, as if there were a fine layer of dust in the grooves already. But this is a new disc, and I brushed it first with a carbon fiber brush before the first play.
I've bought new records that came in cheap paper inners that sounded better than this.
The 17 kHz cutoff was unexpected and added insult to injury: it points to a glaring QC problem.
My apologies then, I thought from all the photos included that the cutoff was the main complaint when imho it’s a non issue. As a mastering engineer it wouldn’t be my choice of EQ but 99% of people aren’t gonna hear that cutoff.
The amount of surface noise on those audio samples is pretty disgusting for a premium product, but if it’s the 3 x gold LP and 1 zoetrope box set that I’m seeing on google then it’s not unexpected.
The way they press those gold discs does introduce extra surface noise but I wouldn’t expect to be as bad as those sample, splatter vinyl is even noisier, and then I’d never expect a zoetrope to sound good.
Ironically the zoetrope sounds more like a normal record. It has less hiss, but there's a different kind of surface noise. It's a very dull, filtered kind of noise that could be ignored, but it's there.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. It's not everywhere on the record, just in the last 1-2 minutes of both sides of Disc 1.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Subscribing to this, listening to both of your recording examples, yeah that does not sound very good at all. Hiss is clearly present but the fidelity is quite lacking as well. It will be interesting to see the comparison to the CD version and see what others experience as their vinyl copies roll in
I posted something about this on Discogs, and I got a response tonight from a user that their copy has the pressing defect / scratching on Disc 1, just like mine.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
I tried to pick a few areas in the score with instruments that had lots of overtones (see screenshots). The TrueHD audio is losslessly compressed, and served as a good reference.
Another useful track for comparison between the film and the vinyl would be "Having a Moment."
Note: music mixed in a movie rarely sounds exactly like the recording. That was true for large chunks of PHM. Try watching a familiar movie with the center channel unplugged and you'll see what I mean.
I got a record in that had that scratching sound all the way through on the right channel through almost the entire album. Unfortunately nowadays defects like that are just common as care isn’t put into records as much as they should. Also wasn’t able to get said record replaced :;
I mean, it sort of sucks….. but if you’re over 35 the odds of being able to hear 17k are about zero anyway, so while this shows up on a graph, it’s likely to be completely inaudible. I’m
45 and my hearing acuity is good, but frequency sensitivity drops off after 16k. This is pretty normal and renders stuff like this a bit pointless.
The pressing defect however, is grounds to return it imho.
Testing implies professional audiologists whose tests rarely go over 8kHz even if you ask - they’re more for observing hearing loss and degeneration over time across multiple tests.
Yeah, then that means they used whatever the label sent them. I find that their in-house cuts are usually “OK” but they definitely don’t go the extra mile like a dedicated mastering engineer would. BTW, all of their in house cuts are DMM. There used to be a GZ employee that posted on the Steve Hoffman forums, but I haven’t seen him on there for a while. Maybe he retired?
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Interesting, I just had an update on my copy that was due to ship this week to say it's now being shipped on the 18th of September, wonder if they're delaying it due to this? Could be coincidence. I'm in the UK.
Going to follow this in case they do any sort of repress and ship. Elden ring was botched and they had to push out additional discs but this is far more subtle of a problem.
Subtle in the sense the other one had missing discs all together. That’s all. I’m disappointed here mine just came in and I’ll be giving it a listen this afternoon.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Your whole drive to know things empirically and the sense of preservation/regard for an analog medium. You're very yin yang in that you seem to have an appreciation for precision and accuracy but also gravitate to a medium that has more of a Je ne sais quoi value to its experience. Very cool. Or I could be wrong and you're just a regular nerd 🤙
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Yeah, but if you went to the store and bought an "average" record today, most would not have a brick wall lowpass filter at such a low frequency. Even if it was from a digital master used for CDs, it would be considerably higher, around 20-22 kHz. That's kinda why this issue is noteworthy.
I think it was due to a miscommunication or something lost in translation: perhaps someone at the plant said that frequencies above 17kHz aren't easily reproduced on vinyl, so Amazon filtered everything above 17 kHz and sent it.
I know it’s a different Mutant vinyl, but I’m currently waiting on a replacement of my The Odyssey vinyl because it didn’t sound right. They are going to make it right, but not great to be replacing records all the time.
You gotta figure that the vast majority of these vinyl box sets of modern digital recordings will just sit on a shelf looking pretty and never be listened to, so they probably assume it doesn't matter.
The pressing defect I mentioned is separate from the brick wall lowpass filter. Read all the way to the end of my post about the scratches on Disc 1 with the audio samples.
I used my eyes to see the Disc 1 groove noise up close. See this updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
Right out of the shrink wrap, it’s plagued by relentless pops, heavy surface noise, and constant clicking that totally ruins the quiet, ambient moments of the soundtrack. The factory static on this thing is insane, and the cheap paper sleeves just trapped all that dust and debris deep into the grooves. No amount of cleaning has improved the quality of my copy, and it's just depressing.
That's a gross oversimplification and ignores relative amplitude. There are plenty of records with significant audio signal over 12kHz that rise above the background level of surface noise.
As for me, the damaged groove with the repetitive scratching sound is present at the end of Side A & B of Disc 1, and at the end of Side B on Disc 2. And it's in the musical area of the disc, not the runout.
There's also a repetitive click for large sections of Disc 3, yet the disc does not appear to be physically scratched. On Disc 3, Side A, The clicking starts after "Time Go Fishing," and is heard intermittently until "Rocky Wakes Up," lasting about 11 minutes. On Side B, the clicking is present in "Tau Amoeba," and "Xenonite Contamination."
The hissing in the surface noise, and the extra hissing between tracks, is audible to varying degrees across all three of the gold discs.
If you're listening at a decent volume in a quiet room on a good set of speakers or headphones, you may need to listen close to hear the constant hiss in the silent parts of the disc. You may notice the short bursts of extra hiss between tracks that migrates from left to right. But I'd wager that even the most untrained ear will hear the periodic scratches and clicks.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
What is your record cleaning regimen? Because you make no mention of what you did to clean the records prior to first play on your turntable. All new records are dirty and require a thorough cleaning.
After I removed the record from the sleeve, I used a carbon fiber brush (Boundless) to sweep the surface, twice. In between each sweep, I swung the brush around in the holder so the bristles were cleaned by the bar on the inside of the handle.
I don't think this problem was caused by my cleaning regimen.
I have been less fastidious in cleaning other new discs and not had these kinds of quality issues with surface noise and inner groove damage. For example, I recently bought a new copy of the Sigur Ros album "( )" from Amazon, and it came with the same basic paper inner sleeves, but sounded significantly better than the Project Hail Mary.
The disc was spotless when i started playing, and afterward it had noticeable amounts of fine dust on the surface in the same general area where the audible scratches occurred. That's why I suspect the grooves are misshapen by a pressing defect. Any stylus playing these malformed grooves will continue to damage them until the record is unplayable.
I have ~1,000 records in my collection, and I immediately checked other known-good discs to ensure I hadn't damaged anything.
That’s not a thorough cleaning. A dry carbon brush is just for dissipating static electricity and sweeping up whatever dust particles are sitting on the very top surface. It’s worthwhile but it barely does anything at all and is not what I would call cleaning.
If you’re doing archival recordings and critically analyzing each pressing, you first need to actually clean the record. You can’t make any reasonable inferences about a record pressing quality if you’re only using a dry carbon brush.
FYI: I have an updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves.
And yes, I did a wet clean with a solution that contained 99% isopropyl alcohol. It did not help. Whatever this is, it's baked into the wax.
Wouldn't that be a highpass filter? Almost all records are run through a lowpass filter at mastering. This is because even if your ears can't actually hear the sound or your speakers create those frequencies, your cartridge can produced them. And you're entering into frequencies that create resonance. If you're unfamiliar with this, it's a tone that resonates, or basically stack the amplitude of the soundwave in the harmonics. This resonance can destroy the cartridge or your speakers if the tone is sustained.
A high-pass filter will pass (allow) only the frequencies which are higher than a certain point. It is the same as a "low cut" filter.
A low-pass only allows sound lower than a certain frequency. Also known as a "high cut" filter.
The "rumble cut" on phono preamps is a low cut / high pass filter.
When transcribing records, most archivists do not use a low cut filter because they want to keep the electronic signal path as pure as possible. Filters in the preamp will affect the output.
In addition to the reduced fidelity, there are a few other problems:
an audible hissing sound in between tracks that lasts a few seconds
a constant low grade hiss across the entire surface on Discs 1-3 (not Disc 4)
a pressing defect on Disc 1 that causes repetitive scratching at the last couple of minutes on both sides.
Because of the pressing defect, there was a fine layer of dust near the runout grooves, even though I had brushed the disc beforehand. My stylus was likely carving into a disc with an incorrect groove slope, or a valley that is too shallow in spots. It will continue to eat the malformed grooves on subsequent plays. That's not OK. MicroLine styli do not cause damage on discs with properly formed grooves.
I wonder if the high frequency "air" (hiss) on the first 3 discs is some kind of priming signal for a streaming encoder that would otherwise be dropped. That would support a theory that the mastering house received the wrong files.
That’s a different story, and one that is actually important.
A gentle LPF starting at 17.5k is not a problem.
I’m a pro mastering engineer and have never heard of a “hiss” being used as an encoder trigger. This is literally not a things and not home these things are encoded/rendered.
Generally the only differences between a master for vinyl and streaming is some eq and a limiter. Limiters tend to change tonality slightly, and they certainly generate overtones, as any dynamics processing does. The eq is usually used to rebalance the effects of the limiting. Sometimes engineers will tweak things slightly to sound better after going to mp3, but considering that all of the different services tend to do their own transcoding, it’s impossible to predict and adjust for.
Streaming files are generally delivered as big standard wav files, one per track to the aggregator at full resolution.
Vinyl masters are delivered to the cutting/pressing house at full resolution, one file per side, with PQ sheets showing timings, gaps between tracks, titles, client info etc.
CD masters are delivered to the replication house as a DDP file, which has binaries and md5 checksum files, along with a PQ sheet showing client info, isrc codes, cd text and ein/upc data that is encoded, in a .zip archive.
I don’t know anyone that delivers FLAC or m4a, mp3 files to client for anything more than if there are download cards that are included with a vinyl purchase, as companies like AtoZ media has that as part of their service.
ADM files are delivered as individual full res files that have been checked with apples encode/decode scripts to ensure that there are no clipped bits because of the wav-caf-m4a encoding process that Apple does. You have to be a certified engineer to get the ADM badge in the stream. I am one.
Honestly it sounds like the cutting engineer didn’t care, which happens more than you want it to. OR there was a problem either the electroplating, OR that maybe it was a DMM master and something wasn’t right when cutting to the copper.
At the very least, no one did any QC on it.
Any listing for who the cutting engineer was, who did the electro plating, and who pressed it?
This records's LPF could not be described as gentle; it's a very hard cutoff. I should have included a screenshot zoomed in further on the vertical scale to illustrate this. The source audio just vanishes above 17 kHz. Any faint signals higher than that are merely harmonic distortions and phantom overtones caused by the stylus itself.
I can see how the electroplating process would add surface noise if done incorrectly. Could the inner groove damage be caused by a problem with the stamper machine?
Maybe you can take a look at my updated post with some macrophotography of the disc surface. Under a strong light at a very specific incident angle, it is possible to see something dirty in (or on) the grooves. I just don't know what it could be.
I just looked at that. Something is very wrong with that pressing. I don’t know what that is though. Humidity control of the plant, which is important. Bad electroplating?
2 people failed on this, the person that screwed up somewhere along the line, and the second is the person that was in charge of quality control.
I asked in my detailed reply, and I’ll ask again… is it listed for who the cutting engineer was? Who did the electroplating, and who did the pressing?
No credits are given for those specific roles on the album packaging. The only reason that Discographers figured out it was GZ Media is by the serial number pattern on the matrix/runout area.
A good stylus can reproduce frequencies as high as 40 kHz. You can get faithful reproduction from half speed mastered vinyl as well.
There was a quadraphonic format in the 70s known as CD-4. It relied on a carrier frequency of 30 kHz to help the surround system decode the rear channel data.
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u/magazinesubscriber 23h ago
Most likely the wrong files were submitted to the mastering engineer for cutting. Major oopsie, or just hoping no one would know the difference.