CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Headphone Measurements => Topic started by: ultrabike on November 11, 2013, 06:56:16 AM
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These were brought over by Milos as well. From what I've read and heard, these were the first electrostatic headphones available, and were put on the market around 1960. This particular sample might have driver imbalance and one driver pad was not attached. I eventually placed the pad on the driver, but measured without it... Maybe if there is a next time I'll measure them again properly.
These were driven by an SRM-T1... And it struggled like hell to do so. It could not reach 90 dB SPL at all. I think I saw 85 dB SPL when the volume was all the way up on the most efficient driver, and the T1 (and/or the SR-1) distorted heavily. If I get the chance I'll probably shot for a 50 or 55 dB measurement.
Anyhow here is what I got out of them (disregard the imbalance magnitude since we played with the volume given the difficulty to drive these, and one driver did not have pads... can't remember which one now):
Frequency Response:
(http://www.changstar.com/index.php?action=dlattach;topic=1228.0;attach=4590;image)
Distortion Right:
(http://www.changstar.com/index.php?action=dlattach;topic=1228.0;attach=4582;image)
Distortion Left:
(http://www.changstar.com/index.php?action=dlattach;topic=1228.0;attach=4584;image)
CSD Right:
(http://www.changstar.com/index.php?action=dlattach;topic=1228.0;attach=4586;image)
CSD Left:
(http://www.changstar.com/index.php?action=dlattach;topic=1228.0;attach=4588;image)
This is a ~50 year old historic headphone and it was built like a tank. It still puts out sound.
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One channel definitely has an imbalance and distorts like crazy most of the time. There are times though where both channels play properly for a while (I think until humidity starts to build up within the cups) and they sound really quite nice. These have a nice midrange. I need to revive these and then remeasure.
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Not bad for 50+ years ago, taking into account the magnitude of the distortion from the headphone compared to the amps and sources of the time.