Valencia 846a rattle/vibration

[TSWisla]

Hello, recently purchased some really beautiful Valencias. They sound really wonderful. I do have a problem though. I noticed a rattle or vibration coming from one of the channels with a couple of songs. I was able to isolate the noise to one of the woofers. Can anyone please guide me on what may be causing this and how I can repair it? Thank you.

[Earl K]

Based on the age of those 846a(s) and the fact that the woofers have extremely narrow gaps ( as well as "loose suspensions ), my guess is that the woofer has a voice coil that is starting to rub on the top-plate ( due to gravity vs time > doing its thing ).

One ( cheap ) possible remedy is to remount the woofer ( turned 1/2 rotation ) so the original woofer orientation is now 180deg.

That rotation might be enough so that the whole cone assembly settles downwards ( a bit ) and away from the offending area of contact ( between voice-coil and gap/top-plate ).

[Riley Casey]

1 - remove the woofer from the cabinet and inspect it visually front and rear for tears in the surround, cone and spider

2 - Download a cell phone app that has a sine wave generator ( Studio Six Digital Audi Tools is good, there are probably cheaper ones )

3 - connect your cell phone headphone out to your amp and your amp to the woofer terminals

4 - Set the sine wave generator on your phone to 100 hz and turn up the amplifier slowly til you hear the tone clearly

5 - Sweep the tone frequency down by hand on the phone screen ( DO NOT use any automatic sweep function ) unit you hear the distortion you're looking for

6 - continue sweeping down no lower than 30 hz and then back up til you find the worst distortion

7 - if the distortion can be localized to a part of the cone or surround you may be able to press on that spot and change or reduce the distortion. If the distortion comes from the venter of the cone near the dome it's probably a bubbled or out of round voice coil and it's time for a recone. If you can isolate to problem to a part of the cone or spider you 'might' be able to fix it with some glue and perhaps some paper

8 - if any of this sounds over the top it's time to take or send the woofer to someone who recones speakers

[grumpy]

As a minor addition to the good advice already provided, the screen in the dustcap can come partially loose, and IIRC, there's a metal disc glued to the center of the magnet on at least some 416 models... had to redo one of those that had come loose... worth a look with a flashlight

[TSWisla]

Gentlemen, can't thank you enough. I turned the woofer 180 degrees and the problem is gone! For future reference, who would you recommend for woofer reconing if I every need it?

[Mr. Widget]

Gentlemen, can't thank you enough. I turned the woofer 180 degrees and the problem is gone! For future reference, who would you recommend for woofer reconing if I every need it?

Great news!

GPA is usually your best source for all things Altec.

https://greatplainsaudio.com


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