trough@ihuxi.UUCP (Chris Scussel) (04/12/85)
Here's another speaker anomaly: Doppler shift. A single speaker cone attempting to reproduce a loud, low tone and a quieter, higher-pitched tone simultaneously will end up frequency-modulating the high tone with the low tone. This happens because the large cone excursions caused by the low frequency tone give the cone enough velocity to audibly shift the apparent frequency of the high-pitched tone as it is emitted by the cone. I read about this some years ago and it seems reasonable, although I've never knowingly heard it. Any comments? Chris Scussel AT&T Bell Labs ihnp4!ihuxi!trough
herbie@watdcsu.UUCP (Herb Chong [DCS]) (04/13/85)
In article <1192@ihuxi.UUCP> trough@ihuxi.UUCP (Chris Scussel) writes: >Here's another speaker anomaly: Doppler shift. A single speaker cone >attempting to reproduce a loud, low tone and a quieter, higher-pitched >tone simultaneously will end up frequency-modulating the high tone with >the low tone. This happens because the large cone excursions caused by >the low frequency tone give the cone enough velocity to audibly shift >the apparent frequency of the high-pitched tone as it is emitted by >the cone. I read about this some years ago and it seems reasonable, >although I've never knowingly heard it. Any comments? > > Chris Scussel > AT&T Bell Labs > ihnp4!ihuxi!trough this used to be quite a problem years ago when people used large drivers well beyond the range they are used nowadays and also with extremely large excursion drivers, typically small drivers that claim extremely low response. fortunately, most people don't design their speakers that way and make extravagant claims about low frequency response much anymore. about the only speakers you may find this in these days are no-name house brand speakers. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu
rfg@hound.UUCP (R.GRANTGES) (04/15/85)
[] Yeah, Paul Klipsch used to rant and rave about that one when the only speaker he made was the Klipschorn. Because of its horn loading, the Klipschorn had minimal diaphragm movement and, thus, minimal "FM Distortion." It's not clear whether anyone was ever able to hear that or not. Anyhow, Paul doesn't talk about it anymore since he sells other (more conventional) types of speakers. I will say that the Klipschorn was mighty clean sounding. But so are many systems of conventional design which break up the spectrum into 2,3, or 4 bands. I have also heard some swell sounding one cone speakers. And the Bose is not noted for distortion either. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg
crandell@ut-sally.UUCP (Jim Crandell) (04/16/85)
> Here's another speaker anomaly: Doppler shift. A single speaker cone > attempting to reproduce a loud, low tone and a quieter, higher-pitched > tone simultaneously will end up frequency-modulating the high tone with > the low tone. This happens because the large cone excursions caused by > the low frequency tone give the cone enough velocity to audibly shift > the apparent frequency of the high-pitched tone as it is emitted by > the cone. I read about this some years ago and it seems reasonable, > although I've never knowingly heard it. Any comments? > It's true. It's the basis of a classical (should I say ancient?) argument against whizzer cones. (Am I the only one around who remembers that one?) -- Jim Crandell, C. S. Dept., The University of Texas at Austin {ihnp4,seismo,ctvax}!ut-sally!crandell
seifert@mako.UUCP (Snoopy) (04/17/85)
A friend of mine claimed he could hear doppler shift on Bose 901s. Seems like these would be a good victom for the effect, since they use full-range drivers. He hooked them up once and playe them for me. (He normally used the big monster ADS 810s ..or was it 910s...whatever) The Bose sounded "quite interesting". I didn't get to listen to the long enough to hear past the bizzareness and hear all the frequency response problems, or the doppler shift, or... Snoopy tektronix!mako!seifert