16 track cassette?

F

Findlay

Member
A bit a a rambling post I'm afraid but I'd love some comments on this!

I'm always amazed how some cassette multitrackers can sound - still very happy with my Tascam 244! When cassette 8 trackers became available it seemed unbelievable at the time but they also seemed very capable in good hands. Hadn't realised how good the Tascam 238 was until I found a post on the forum the other day with quite favourable comments:
https://homerecording.com/bbs/user-...m/tascam-238-8-track-should-i-go-there-36503/

Seems there as a dbx version with S/N of about 90 dB and Dolby S version (238S) with S/N of about 75. Seems that 2 Tascam 238 decks can be synced together using an external box to make a effective 14 track - a track from each being sacrificed for the sync tracks. Wonder if anyone has used them like this? I like the idea as it would mean you could do the final tracks on a new cassette on machine 2 without all the tape wear of the previous 8 track recordings.

Which brings me around to wondering if tape development hadn't stalled 25 years or so ago, someone might have made a 16 track cassette that sounded pretty good - maybe even bumped up the speed to 7.5 ips to maintain or even improve on the the 75 dB Dolby S S/N. That would have been really something! (I guess 24 tracks on 1/4 inch would have been good too!).
 
It could certainly have been done, but I think the crosstalk might have been prohibitive, and edge tracks would have been a challenge.
 
I agree. 8 tracks on 1/4 inch tape is a lot to ask. Even 4 track cassettes only have 3/4 the track width of 2" 24 track decks. (if my math is correct). That track width is cut in half for 8 tracks and in quarters for 16 tracks...
 
2" tape is about 50.2mm...so that's about 2.1mm/track for the 2" tape running 24 tracks.
A cassette has 3.81mm wide tape...so if you have 4 tracks on the cassette, they are only about 0.95mm each...8 tracks would be 0.475mm each...and at 16 tracks, they would only be about 0.194mm each, which would be like 2 hairs width. :eek:
So 2" tape track width is more than 4 times wider than cassettes tracks at their widest format.

And that doesn't even take into account the edge tracks, which would make the recording tracks even less.

I think I did that math right. :D

So if you have 2" 16-track....the track widths are going to be about 3.14mm each...which is almost as wide as the whole cassette tape. No wonder that 16-track 2" tape sound so much better. :cool:
I keep looking for a 16-track head-stack to come up for my MX-80...but I think I'll look for some black pearls instead. :p
 
Here's the trick...the guard band (the space between the coils in a headstack) has to be a certain width in order to afford a minimum acceptable crosstalk spec. The actual width of a head coil in a Teac 4-track cassette record/play head is 0.5mm +/-0.03mm, so about half the width of your calculation, Miro. The rest is guard band, and as you add tracks you don't necessarily reduce the guard band width commensurate with the reduction in coil width...it's not linear. Otherwise the crosstalk spec would get worse. So as you add tracks your coil width will become even more narrow than simply dividing by 2 if you double the tracks. There are ways to mitigate this, like the staggered heads in the 238 to help with the crosstalk spec, but they had to employ the staggered head to maintain decent crosstalk performance.

I'm just spit-ballin' here, but I expect the coil width on a 16-track cassette format would be less than 0.1mm. I don't think the performance would be marketable.
 
Yeah...I knew there was more to it than just dividing the tape with by number of tracks...:D...I was just comparing the general differences in track widths between 2" tape and cassettes.

There's no way they could fit 16 on a cassette tape.
Heck, I remember being kinda surprised when the 8-track cassette recorders first came out. I though that 4-track was going to be the most you would see on cassettes.

I can appreciate the compactness and ease of use with multitrack cassette recorders...great for capturing scratch tracks and working out songs...sometimes, you even can get some really decent stuff down on a good cassette multitrack...but I wouldn't bother with them for anything more serious...I mean, if you're really looking for the tape sound and all.
 
Sorry, man...wasn't trying to be smarty-pants-know-it-all...I should know you know such things. :o

I've heard some really, really good stuff tracked on cassette multitrack. Part of it I think was the material itself, the style, but also mics and mic placement...but really good music...you wouldn't know it was cassette. But cassette has sonic boundaries that are more restrictive than open reel formats with greater head-to-tape real estate. Cassette is analog so it will have character, but it's a fool's adventure to think analog cassette tape will get you phat tape mojo shiz. That comes from 3rd order harmonic distortion and the amount that can be elicited from the Philips analog cassette format before you hit straight-up clipping is not what you can get from 1/4" track at 15ips, for instance
 
But you are a smarty pants, know it all with this kind of stuff...;)
You know more of those small, important details than I do, that's for sure.
 
I just have a stupid sized collection of manuals and tech docs. Trying to find the specs on some larger stacks to compare.
 
Teac 4-track (Philips) cassette 4-track:
* track width = 0.5mm
* guard band = 0.5mm (between tracks 1&2 and 3&4), 0.7mm (between tracks 2&3)
The guard band varies from being equal in size to the track width, to being 40% greater than the track width.

1/2" 8-track:
* track width = approximately 0.76mm
* guard band = approximately 0.87mm
The guard band is approximately 15% wider than the track width.

1" 8-track:
* track width = 1.78mm
* guard band = 1.52mm
The guard band is approximately 15% more narrow than the track width.

Unfortunately, it appears it's no easier to find the head specs on Teac's 8-track cassette head as it is to find them for the 1/4" 8-tack...I tried pretty stubbornly some years ago to get the 388 head specs but...no luck.

Anyway, the overall trend is toward an increase in guard band width as the tape width shrinks and track count grows.

Using the above data I'm calculating the track width of a 16-track Philips cassette format to be about 0.1mm, with a guard band of about 0.14mm.

The transport would have to be pretty fancy because there would be absolutely NO room for error with physical tape tracking...the alignment of recorded tracks with the coils in the headstack on playback would have to be precisely accurate.

Hm...I wonder what the thickness of the coil laminations was in late generation magnetic tape heads...I know the Ampex AG-440C head coils were constructed of 0.025mm laminations...surely the laminations were much thinner toward the end of the analog era some 15+ years later...but how much thinner? Even if the laminations were thinner by a factor of 4 that would still mean 16 laminations per track on this hypothetical 16-track cassette machine. Oh the questions. :drunk:
 
Thanks for these responses guys and for all the figures Sweetbeats. I was wondering if a precision head (or couple of heads) could have been fabricated using thin film techniques? I think the crosstalk figure for the 238 is around 70dB - I guess for a 16 track set-up with the sort of guard band you have calculated this would drop by a little more than 3 dB to around 66dB.
 
It's perhaps worth mentioning that LTO-7 has 3584 tracks on 1/2" tape. I think there's only about 32 tracks on the head, so the thing is repositioned with an actuator and it does weird shingled recording things which are only really feasible for digital data. However, the heads themselves are extremely high density so someone's figured out how to do it.
 
I'm amazed sometimes how good some old 4-track cassette recordings I made sound today. Especially when I dump them in to my daw and remix them with 20 more years of experience lol.

A band mate of mine in the 80's bought a 238 and I distinctly remember the recordings being hissy and kind of weak sounding. Could have been other factors but he was an experienced guy. I don't think any more could have been done with that format.

I wish the Elcaset format had grown some legs. That probably could have been modified to run 8-16 tracks at 7.5 ips, and probably be portable.
 
leddy said:
I'm amazed sometimes how good some old 4-track cassette recordings I made sound today. Especially when I dump them in to my daw and remix them with 20 more years of experience lol.

A band mate of mine in the 80's bought a 238 and I distinctly remember the recordings being hissy and kind of weak sounding. Could have been other factors but he was an experienced guy. I don't think any more could have been done with that format.

I wish the Elcaset format had grown some legs. That probably could have been modified to run 8-16 tracks at 7.5 ips, and probably be portable.
Click to expand...

What is it with people and all the hissy cassette recordings? Are they not using the NR I guess? I do a decent amount of 4-tracking, and tape hiss is a non-issue to me. Or ... at least it's negligible if anything. In other words, I'm more concerned that ambient noise in my house/studio, such as the A/C, computer hum, etc. will be audible than tape hiss.

Having said that, I always use the NR. I started doing this simply on the advice of the manual, and I've kept doing it because I've never heard anyone say, "Yeah, it sounds pretty good, but it sounds as though you have the NR on. You should turn that off and it'll sound better."
 
Glad you said that famous beagle. I think the S/N of the 244 is phenomenal - you can't defeat the dbx but who would want to? (made my own switch for track 1 for tape sync). Biased up for type 1 tape, dbx artifacts virtually disappear too. Freq response is 0dB at 40 Hz, flat to 16kHz, -2dB at 17kHz, 0 VU record level.
 
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Findlay said:
Glad you said that famous beagle. I think the S/N of the 244 is phenomenal - you can't defeat the dbx but who would want to? (made my own switch for track 1 for tape sync). Biased up for type 1 tape, dbx artifacts virtually disappear too. Freq response is 0dB at 40 Hz, flat to 16kHz, -2dB at 17kHz, 0 VU record level.
Click to expand...

Yeah, exactly. I hear some cassette recordings that sound like a hail storm before the music starts, and I don't get it. I guess they're not using the NR and they're setting terrible levels or something. I don't know. But I couldn't produce that much hiss if I tried!
 
In the early 1990s my band recorded a full-length album on a Tascam 488 mkII. We used the onboard mixer for most of tracking and overdubs except for using an EV sound reinforcement console to submix the drums...we mastered to DAT using the onboard mixer. We used the onboard dbx n/r. The noise floor is very, very low. I'll have to pull out the final product again sometime but I recall listening to it a couple years ago for the first time in many years and feeling surprised at how good it sounded.
 
sweetbeats said:
In the early 1990s my band recorded a full-length album on a Tascam 488 mkII. We used the onboard mixer for most of tracking and overdubs except for using an EV sound reinforcement console to submix the drums...we mastered to DAT using the onboard mixer. We used the onboard dbx n/r. The noise floor is very, very low. I'll have to pull out the final product again sometime but I recall listening to it a couple years ago for the first time in many years and feeling surprised at how good it sounded.
Click to expand...

I'd like to hear that too.

Yeah, I've said it many times before. 4-tracks were used by beginners mostly when they gained their rep. And that usually means:

Bad instruments
Bad mics/outboard gear
Bad musicianship
No recording experience

If you took all that to Abbey Road, you'd still end up with shite! But if you took Geoff Emerick, a decent musician, and good song to a kid's studio with a Tascam 244, a shure SM57, a Yamaha SPX90, and some Squire instruments, you'd still come out with something that sounded pretty good.

The most important piece of gear by far is flesh and blood. You may need pro gear to get that last 5 or 10% of pro sound, but the first 90% takes know-how and skill with just about any medium, IMO.
 
I'd also like to hear that!

I guess the very low noise of the 244 made me wonder about a 16 track. I could live with 6-8dB or so more noise as a result of the extra tracks - would still be inaudible in my book. Freq. response would be the same (better if at 7.5 ips) - crosstalk would be the main problem I suppose but dbx is pretty good at reducing this too. I think I could live with 65dB having grown up with vinyl! And tape developments might have helped the first two quite a bit - and thin film or other head design with the crosstalk. Just the mechanical side as the main headache......... if only.
 
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