What I didn't know about track width...

O

ofajen

Daddy-O Daddy-O Baby
I recently reminded myself that 1/4" 2-track machines have one of three track widths: .100" on DIN (European) machines, .082" on "NAB" machines and .075" on Ampex (and some other machines).

Richard Hess has a nifty webpage on track widths for all sizes of tape:

http://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/analog-audio/

What I hadn't noticed before was that 1/4" 4-track machines have EXACTLY the same track width as 2" 24-track machines, that is, .043", and 1/2" 8-tracks are almost the same at .040". I found that a little surprising. The key difference is that 2" 24-tracks have much wider guard bands (.041") than 1/4" 4-tracks and 1/2" 8-tracks (.025").

Standard "wide-track" multi-tracks (1/2" 4-tracks, 1" 8-tracks and 2" 16-tracks) all share the same track width of .070". 2" 16-tracks have .057" guard bands, and the other wide-track formats have similar guard bands.

Just thought folks might find that interesting.

Cheers,

Otto
 
Well that's just the kind of stuff I DO find interesting.

I've be-bopped around Richard's site before for number of things and never saw that one.

Very cool.

Thanks.

That IS interesting that 1/4" 4-tracks and 1/2" 8-tracks have a very close track width to a 2" 24-track. The guard-band width would play into the crosstalk specs, yes? Anything else?
 
Richard Hess has a lot of good info on his site. I spent a few months reading everything, but I don't remember this part either. Thanks for the info.
 
sweetbeats said:
That IS interesting that 1/4" 4-tracks and 1/2" 8-tracks have a very close track width to a 2" 24-track. The guard-band width would play into the crosstalk specs, yes? Anything else?
Click to expand...

Yes, the narrower guard band increases cross-talk. AFAIK, that's about it.

Cheers,

Otto
 
Which (just stating the obvious here for the sake of bringing the point full-circle) means you can hit the tape harder with less fear of track-to-track bleed...becomes more important as the SOL of the tape you are using increases (i.e. whether you are using +0, +3, +6 tape, etc...) depending on how you are utilizing the tape (i.e. how hard you like to hit the tape and what kind of material is being tracked).

Again, thanks for putting this up, Otto.

Track width is only part of the picture...head design (head profile, lamination construction, materials, etc.) plays heavy into it, and of course the amplifier electronics...just because a certain 1/2" 8-track has very nearly the same track width as as a 2" 24-track does not mean it will *sound* like a 2" 24-track, but it also means folks running 1/2" 8-track decks don't have to roll over and get jeered by a 2" 24-track operator for having a "narrow format" deck either.

This info is a valuable piece to add to the list of things to consider when shopping for a deck to sit your needs as a first-timer or as an "upgrade" or even a "downgrade". And subjectivity will *always* be on the list because only your ears can make the final decision.

I still maintain that one of my favorite sounding decks was my first one, and so my ears were young, but it was a Teac 3340S and what got me was how my electric bass sounded when I accidentally played back material tracked at 15ips with the speed switched to 7.5ips. That showed me all the LF material that was in the 15ips recording and I was stunned.

I love the sound of my Tascam BR-20T 1/4" halftrack...My 388 sounds great too...amazing actually for track widths in cassette territory. And I can't wait to experience my Ampex MM-1000. All different and I'm happy to have at least enough wisdom to appreciate each for what it is, pros and cons. Its more fun that way. :)
 
I brought this up in the past when discussing Tascam’s 1/2" 8-track format compared to 2” 24-track. It gets really interesting here as the track width for Tascam 38/48/TSR-8 etc is .039 inches and the track width for 2” 24-track varies a bit by manufacturer. I had them listed anywhere from .038 - .041 inches based on the models I have specs for. But yeah the differences between the track widths themselves are insignificant.

As noted, the bands in between tracks are smaller for 1/2" 8-track, but something like the TSR-8 has very similar crosstalk specs to the Otari MX-80 24-track. The specs are worded differently. Tascam lists the TSR-8 as Better than 50 dB down @ 1kHz and 250 nWb/m. Otari lists the MX-80 as less than 55 dB of crosstalk at the same frequency and flux level. With dbx engaged the TSR-8 has crosstalk of 82 dB down.

My initial post was in the context of perceived but erroneous ideas about “Pro” vs “Semi-pro.” My experience being that what you have with a ½” 8-track is not inferior performance, but simply fewer tracks than 24 on 2”. Someone (whose initials have varied) didn’t like the idea too much and the thread got a bit heated, so I won’t revive it. ;)
 
it is history

Looking at the various track width and spacing is a look into engineering history. Those folks who decided on a specific track width and spacing were taking the hardware capabilities of the day into account and deciding which factors (S/N vi Cross talk vs etc) were most important and coming up with a configuration that fit their best expectations.

The next generation followed their lead and the standard continues.

All very interesting and in some cases moot with new materials, devices and construction.

--Ethan
 
Forgot to mention the Otari MX5050 MKIII ½” 8-track vs. the Otari MX-80 24-track for a more direct comparison. They have the same listed crosstalk… “Less than 55 dB.” The difference is the MX5050 is slightly hotter at 320 nWb/m. If anything that should negatively impact crosstalk, but it doesn’t in this case.

It was way before my time, but I know when 24-track on 2" was introduced the industry didn't think it would catch on. It was and still is considered by many as, "Narrow track." :)

And for some fun trivia for those that don't know... Tascam invented and developed 1/2" 8-track. Otari and Revox followed their lead and have the same track spacing, so anything done on the MX5050/8 and the Revox 278 can be played back on Tascam machines and vice-versa. Tascam R&D resulted in some advancements in head design, especially in regards to shielding between tracks to reduce crosstalk... and that was carried over to even narrower tracks like 16 on 1/2" and 24 on 1".

The crosstalk spec for the TSR-8 is even slightly better than the older Otari MX-70 1” 16-track. It’s all about innovations in head design. That and noise reduction gave us the best machines ever in those last days ( late ‘80s – early ‘90s) before the digital age was fully upon us.

:)
 
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So is it safe to presume that 1" 16 trk has the same specs as 1/2" 8trk or is there something different there?

ChrisO :cool:
 
Yeah Chris,

More or less, but depends on the particular model. Track width for 1" 16-track is a bit narrower, but not much less than that of 1/2" 8-track or 2" 24-track. It’s an older format than ½” 8-track however so you may see some 1” 16-track machines that don’t perform as well as some newer machines with narrower tracks.
 
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