Sound Quality Troubles Digitizing Old Cassettes

i purchased a Riptunes boombox (amazon dot com/gp/product/B08Q35KQS6) in order to digitize some “old” out of print music cassettes that were never made into CD’s back in the '80’s. these are just some old tunes that have sentimental value that i was hoping to digitize to listen to from my Mac, iPhone, & HomePod.

so i insert a USB thumb drive into the boombox and it records the music to a WAV file. the WAV file is not a standard WAV file, so i then have to convert it before importing it into Audacity. i convert it to AIF using this Audio Converter app (mediahuman dot com/audio-converter).

i’ve done a handful of cassettes so far and am just not happy with how the sound quality is turning out. i realize that they’re old cassettes & don’t expect it to sound great or anything, but it seems to me that it should sound better than it is.

i’m just learning Audacity enough to accomplish this task, so i’m hoping that some of you might have any suggestions on if there’s anything i can do in Audacity to help this sound better.

to me, it sounds a bit distorted (clipped?) even tho there are no red clip marks & the volume meter is not going all the way up to 0 db. and also like there’s no sonic separation (dynamic range?).

in researching all this, i happened to come across one cassette in particular that someone else digitized & put up on Youtube. theirs sounds SO much better than mine!!!

so i downloaded theirs and brought it in to Audacity to try & compare mine & theirs to see if i could figure anything out, but am coming up empty. i’ll attach a screenshot of the two versions (lined up) below.

i created a 30 second export too that i thought i’d attach here but the forum won’t let me. so if it would be helpful to see/hear yourselves, here is a temporary Dropbox link to the Audacity file.

much appreciation for any insight.

I can’t listen at the moment but that waveform looks terrible! :frowning:

My 1st guess is that the Cassette digitizer deck is the problem. I assume it sounds OK when you just play it?

If it sounds OK when you play it, and if you have a desktop/tower computer with a regular soundcard you can record the headphone output into the line-input (blue) on the soundcard.

Most laptops only have mic-in and headphone-out, and the mic input won’t work properly for this. In that case, you’d need a USB audio interface with line-inputs to digitize the analog output.

People seem to have a lot of trouble with those “cheap little” USB cassette players. It seems to be hit-or-miss… (Those are usually about half the price of the one you have, and the USP port plugs-into a computer instead of a USB drive.)

That’s weird… Can you share that “bad” WAV on the dropbox?

@DVDdoug ,
thanks for your reply!!!

yeah, i guess unfortunately i bought the wrong thing to digitize these cassettes :frowning:
and also unfortunately, i’m stuck with it at this point (at least for now).

to answer your questions/comments:

  • yes, it sounds just fine playing the tape in the boombox. actually sounds better than i had expected with such old cassettes.

  • the only computer i have is a Macbook & its only audio input is the headphone/mic combo aux port. i did experiment with coming out of the boombox headphone port with a cable straight in to the Mac’s mic port, but that didn’t work. first, it was “mono” not stereo. & second, i couldn’t get the volume up high enough for it to register very well in Audacity. i tried with three different cables (1 ring, 2 ring, & 3 ring).

  • i ripped a small section (i think the same part as i previously provided the screenshot & Audacity file of) and without converting or anything, here’s (Dropbox link below) that original WAV the boombox creates. i’m guessing Riptunes set it up to create this WAV file without considering Mac users. i have no trouble playing other Wav files; this is the first one/kind i’ve ever run into that Mac can’t natively open. i had another sound person tell me it uses a non-standard codec. so since i can’t open it without converting it, i can’t know if it’s the boombox or the conversion to AIF that’s causing the problem.

note regarding the wav file: oddly, after digitizing a couple times, it’s started adding a few seconds of audio fragments from previous digitizations at the end of the latest digitization. i’ve just been editing those out in Audacity. i only mention this in case you listen to the whole clip; you’ll hear an abrupt transition to a different song at the end.

this particular boombox got good reviews on Amazon. so either everyone who wrote a good review doesn’t have good audio cares, or i got a dud.

without buying a whole different cassette player with proper digitizing skills or better outputs & get a better USB interface, i’m not sure what i can do.

it would be wonderful if Audacity has some trick(s) that can fix what i have. but i’m not holding my breath :expressionless:

for some reason, this forum system keeps limiting my ability to provide links & attachments. this time it’s telling me i can’t link to dropbox (even tho i did previously). so here’s the link with domain dot separation…
“dropbox dot com/s/p41idn9w7hnrgci/FILE0000.WAV?dl=1”

https://wiki.multimedia.cx/index.php/DVI_IMA_ADPCM

Audacity won’t open it, But “audio.online-convert” will convert it into a playable (mono) wav …

Right!

I checked your file with MediaInfo and it says 4-bit mono ADPCM, (Some phone systems use ADPCM.) “Regular” WAV files and CDs are linear PCM (1). As you may know, CDs are 16-bits, and you should be able to get stereo!

ADPCM is like a kind of compression so it’s not as bad as regular linear 4-bit PCM but it’s still NOT “high quality”.

The Behringer UCA202 is popular and inexpensive. Behringer makes a couple of similar units, one with switchable line/phono inputs so you an also digitize records. Behringer also makes some higher-end interfaces.

I recently bought an ART USB Phono Plus which has switchable mic-phono inputs and a recording level control. (Since your headphone output has a volume control, a recording level control is not so critical.) Or there are lots of higher end audio interfaces with switchable pro-mic/line inputs. (Stage & studio mics are not interchangeable with "computer mics.)

(1) Usually linear PCM is just called “PCM” but for some reason it’s called “LPCM” on DVDs.

@Treb0r - i’ve been using the audio converter i mentioned in my first post. i’m assuming it’s just converting the file type and not making any modifications to the audio (like stereo to mono etc).

@DVDdoug - ah, so it is digitizing it as low-quality & mono (argh).
if i get that $30 Behringer device you linked to, can i use a simple cable adapter, where one end plugs into the small headphone out of the boombox and the other end be the RCA style plugs to go into this device?

i’m assuming doing it this way would give a much higher quality digitization (at least as high as the cassette itself is) as well as retain the ‘stereo’ sound.

to all - so i gather Audacity has no magical ability to fix what the boombox is giving me; is that right?

thanks!

If you apply a low-pass filter at 10kHz, (48dB/octave),
the grittiness caused by the low bit-depth is reduced.
Then some pseudo-stereo, and that’s about as good as you’re going to get, IMO.

If everything goes "as expected the digital recording should sound virtually identical to what you’re hearing out of the headphone jack.

Right. You can make “little fixes” like boosting the bass or treble (although boosting treble will boost tape hiss) and sometimes noise reduction helps too (or if the noise is bad the side-effects of noise reduction can make “the cure worse than the disease”.

Yes, like this.

Since you may remember recording with analog tape… Analog tends to saturate and soft-clip if you go into the red so with analog tape it was OK to occasionally go “into the red”. Plus you wanted a hot signal to overcome tape noise.

Digital is hard-limited to 0dB and it hard-clips if you try to go over. But there is no tape-noise so you can record at a lower level leaving more headroom. And you can amplify digitally later without quality loss. Low recording levels are better than high recording levels.

ah. okay, thanks for the great tips!!!
much appreciated.

Update & another Question…

i decided to go up a small level for hopeful future home recordings, so i purchased the M-Audio Air 192/6.

i also got a 3.5mm TRS to dual 1/4" TS splitter cable.

do i plug the 1/4" cables into the LINE or INSTRUMENT ports on the audio interface?

it seems to me that it should go into the LINE input since it’s not an instrument. but the M-Audio specs say that’s for “balanced” plugs & the INSTRUMENT port is for “unbalanced” plugs. and from what i’ve read, a TS is Unbalanced & a TRS is Balanced. so that means it should go into the INSTRUMENT port (yes/no?).

Normally it should be a line input but the instrument input should work too. You might try them both.

Line level signals and instruments are about the same voltage and they are often interchangeable. The instrument input may have more gain. The main difference is that guitars like high impedance (usually around 1M) and line connections can work with a lower impedance load.

It’s Ok to connect an unbalanced signal into a balanced input and usually the best “adapter” is simply a TS (2-contact) plug instead of a TRS (3-contact). So you can use the same plug into both inputs.

awesome. thanks @DVDdoug!

I was just reading down through some posts and came across this. Good you got it going.
The Boombox itself should record to USB stick or SDcard as MP3 or maybe has options for other types.
Can you play the USB stick file on any other USB player, before file conversion by any other software.
Or if you post the file before any conversion here or a link to it we will see what type file it is…

@AudyMusik - thanks for your msg.

the boombox does have both a place for a USB thumb drive & an SDcard. but the quality of the audio it creates is aweful. distorted & clipped. i can’t get any reply from the manufacturer. so now i’m going this route (headphone port > audio interface > record manually). the quality is leaps & bounds better.

i did provide a snippet in its original format above. it’s not easily noticeable because i have to strip away the parts that make it a clickable link. for some reason this forum won’t let me post more than one or two links & attachments.

but anyway, i think i’m good now.

Sorry, I didn’t see you had already posted FILE0000.
It imports into Audacity as Raw audio…but has alot of noise.
Plays better in VLC player and VLC detects it as ADPCM.
I think you already have the best solution sorted with using the analog ports.


well this is odd & unexpected…

so i have the boombox connected to the Line inputs of the audio interface, and that is connected to my Mac via USB-C.

all level knobs on the audio interface is all the way down, yet when i play the cassette & turn up the boombox volume, i’m hearing it thru my speakers and Audacity is registering its levels.

i have “Monitoring” turned on so i ‘can’ hear as it’s playing/recording, but i did not expect to be able to hear anything with the audio interface levels all the way down.

if i raise the interface input levels, it does turn it up in Audacity even more.
i understand that the boombox volume needs to be up some, but i thought i’d have to juggle between the boombox volume & the audio interface input levels; and it makes sense in my head that if the middle-man (audio interface) has its inputs all the way down, then Audacity should not be able to ‘hear’ the cassette.

is this normal behavior? is there a setting in Audacity for this?
if not, i guess i should contact M-Audio support.

thx.

FYI. spent 2 hours on tek support chat w/ M-Audio. they say this device is defective. having to return it then get another.

UPDATE: well, i returned it (Amazon) & re-purchased the same thing (thru a different Amazon seller); got it today, plugged it in, and the same exact problem.

i’ll start a new thread topic since this is off-topic of my original questions. but wanted to give a quick update, since you all have been so kind & helpful.

in case you’re interested, it’s @ Signal Passing Through Audio Interface When Knobs Are At Zero

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