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Did old (1960s) chart recorders use smoothing?


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Did old (1960s) chart recorders use smoothing?  How much?  How would we compare the speaker frequency response curves we see in old copies of High Fidelity magazine with modern curves that we run with on something like REW, with 1/3 octave, 1/6 octave smoothing, etc.?

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Apples and oranges. It's not the recorder (yes I've used them) but the rest of the set-up. The test room is the overwhelming variable and I would take the curves you see in old High Fidelity or Audio articles as general indications of a speaker's response, but not with the precision we now have with REW and its peers. If you see near-field measurements of bass response in the later years of Audio it's pretty accurate since the room was taken out of the variables. 

 

The old chart recorders hooked to the typical General Radio BFO analyzer had "smoothing" but not by design. The inertia of the mechanical stylus (pen) created a degree of "smoothing" but not designed to be "1/3 or 1/6 octave" etc. With the exception of the later years of Audio (Mr. Heyser) I'm not sure any of the mags published raw curves, especially High Fidelity which was notorious for twiddling with the curve to make it look prettier. The exception I recall was there review of the LaScala, which got PWK riled up so much that the mag disavowed the review.

 

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4 hours ago, boom3 said:

The inertia of the mechanical stylus (pen) created a degree of "smoothing" but not designed to be "1/3 or 1/6 octave" etc.

 

I read this and thought about the plotters I used to work with as a computer operator in the late 70's. Programmers used to complain about it as the data points weren't always on spot.

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Protesters against the practices of the UC Berkeley administration in 1964/65 wore punch cards dangling on ribbons around their necks with "HUMAN - Do not Fold, Spindle, or Mutilate" written in big letters on them.

 

If any of you old timers saw chart recorder sweeps of, say, Heritage speakers in the Paleolithic, let me ask my question another way, how might a chart recorder frequency sweep of a speaker look compared to a modern REW curve?  Might it resemble 1/3 octave, 1/6 octave, or what?  Go ahead and guess.

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