Similar to how the different film stocks affected the look of the image, the different tape formats would effect the sound similarly. Crudely explained, the more light brown the tape, the more noisy it would be. The darker the tape, the cleaner it could be. If you like the sound of someone standing behind you constantly saying shhhhhhhhhhhhhhhhhhhh, then choose a brown tape.

By now, the audiophiles have lots of profiles of what the various tape formats would sound like. It's been ages since I've looked at audio plugins, but I would be shocked if there's not presets to make your pristine audio sound like a Maxell cassette that's been played hundreds of times.

U-he Satin emulates Dolby encoding/decoding.

The only one I'm aware of is DDi Codec by Anaxwaves.

Dolby was just pre-emphasis of the higher frequencies before they were written to the tape.

It will sound the same with 8 bits. 8bit quantization will give you 48dB dynamic range (best case). Call it 36dB practical, around the same as an average cassette tape.

Back in the day, the plastic that wrapped blank tapes was printed with details about the tape inside, including a frequency response chart.

Of course it differed by brand.

It's also worth considering that a lot of tapes were recorded with Dolby B noise reduction, which boosted high frequencies on the recorded tape, to increase the signal to noise ratio. (You had to use Dolby B at the playback end, too, or it would sound too bright.)

Looking at the first example [1] looks like there is high pass, low pass, and two more “cuts”

[1] https://github.com/AARomanov1985/Audio-Cassette-Simulation/b...

I’m not sure of the correctness, but I see the author adjusting eq in the source, this is from the “BASF LH Extra C90” preset:

> highpass=f=50,lowpass=f=13000

> equalizer=f=500:width_type=q:width=0.8:g=-1.2,equalizer=f=6000:width_type=q:width=0.7:g=-4

Half of wow and flutter. The tape speed wasn't perfectly constant, so the pitch wobbled.

Wow was slow speed variations (under 4Hz). Flutter was quicker warbles.

Both were caused mechanically. The rubber wheel - pinch roller - that moved the tape might not be perfectly circular, the motor that pulled the reels might be uneven, and the tape case sometimes pressed on the tape reels causing variable friction.

Analog media really were a bit crap. I get the creative distortion idea, but even so - ewww. I'm so happy these kinds of imperfections are optional now, and not baked into music distribution systems as an expected flaw.

Basically, on analog media, playback speed isn't perfect. There's constant speedups and slowdowns. This creates a "waa waa" or "wow wow" effect that's noticeable when playing a constant pure tone.

It's a kind of pitch instability: https://en.wikipedia.org/wiki/Wow_(recording)

That might be of interest: https://ntsc.rs/

Of course ! By the way, I'd love to see more HN posts about NAM. I've been following the project since day one, and it's been an absolute game changer for guitar amp modeling. It's genuinely exciting to see an open-source project have such a profound impact on the entire industry,not just modelers but software plugins and hardware solutions

You might want to have a look at https://github.com/jatinchowdhury18/AnalogTapeModel

Available as a (free) DSP: https://chowdsp.com/products.html#tape

Most commercial DAWs come with such algorithms already. (eg Logic Pro has "ChromaGlow" which can emulate tape, tubes, etc. https://support.apple.com/guide/logicpro/chromaglow-controls...)

There's also a thriving 3rd party plugin market for similar effects.

i don’t think any dynamic range manipulation is being done, beyond the slight variations as a consequence of the other processing.

generally 0dBVU is mapped to -18dBFS with VU style RMS metering being used on the digital side as well. but that isn’t some kind of physical translation, it’s rather arbitrary and more a convention.

Crappy old tape and a warped shell can cause wow and flutter too if the tape is sticking or the reels are binding.