Michon
07-05-2019, 10:58 AM
Good day folks.
I am a long time lurker here, but this is my first post. Part of the reason for this is that unfortunately Altec transducers are rare in Southern Africa. Despite this I was lucky enough to acquire a pair of Altec 950-8A duplex speakers recently. Unluckily a spider on one of them produces a resonant/flapping sound when playing low frequencies. I suspect this occurs because the horn had an excessive force applied to it that caused a crease to develop over a few of the corrugations of the spider that is attached between the horn and the woofer diaphragm. I hope that removing the spider, tightening the horn and installing a new spider will fix this problem and that no further damage is present.
Below is a link to two videos illustrating the fault condition. In the videos I play a 50Hz sine wave through the woofer.
The data compression applied to the videos by the host site has significantly reduced the resolution of the videos. I apologize for that.
Are there detailed photos or graphs of the anatomy of these transducers that I missed in my internet searches? An interesting aside: the baskets of the 950-8A look exactly like EVM15L baskets, except that there is a compression driver mounted in the middle of the magnet assembly.
Is there a company, such as Great Plains Audio, that sells suitable replacement spiders for this model of Altec speaker?
Link to the videos: https://www.dropbox.com/sh/c54hskdyu9pxzgz/AAAwYyU3oCMLR-6JwphUYVgDa?dl=0.
Internet photos of the Altec 950-8A (for those whom are unfamiliar with them): https://picclick.fr/Vintage-Altec-Lansing-Milestone-950-8A-15”-Duplex-Full-273697624460.html.
I am a long time lurker here, but this is my first post. Part of the reason for this is that unfortunately Altec transducers are rare in Southern Africa. Despite this I was lucky enough to acquire a pair of Altec 950-8A duplex speakers recently. Unluckily a spider on one of them produces a resonant/flapping sound when playing low frequencies. I suspect this occurs because the horn had an excessive force applied to it that caused a crease to develop over a few of the corrugations of the spider that is attached between the horn and the woofer diaphragm. I hope that removing the spider, tightening the horn and installing a new spider will fix this problem and that no further damage is present.
Below is a link to two videos illustrating the fault condition. In the videos I play a 50Hz sine wave through the woofer.
The data compression applied to the videos by the host site has significantly reduced the resolution of the videos. I apologize for that.
Are there detailed photos or graphs of the anatomy of these transducers that I missed in my internet searches? An interesting aside: the baskets of the 950-8A look exactly like EVM15L baskets, except that there is a compression driver mounted in the middle of the magnet assembly.
Is there a company, such as Great Plains Audio, that sells suitable replacement spiders for this model of Altec speaker?
Link to the videos: https://www.dropbox.com/sh/c54hskdyu9pxzgz/AAAwYyU3oCMLR-6JwphUYVgDa?dl=0.
Internet photos of the Altec 950-8A (for those whom are unfamiliar with them): https://picclick.fr/Vintage-Altec-Lansing-Milestone-950-8A-15”-Duplex-Full-273697624460.html.