Looking to refurbish a set of newly acquired set of Bose 401 speakers. They are in pretty good shape except for one of the tweeters. Mine are part number 131011. I have seen reference to 146056 as well. I have been searching the web for replacements with not much luck. I'm someone here might be able to help.
The original is a 2", 4 ohm tweeter which is pretty much unobtanium.
It could be replaced with an 8 ohm tweeter provided the tweeter's series capacitor of value 4.5 uF is changed to 2.2 uF
Here's a possible replacement tweeter: https://www.visaton.de/sites/default/files/dd_product/TW 6 NG_1000.pdf
If there is a difference in tweeter sensitivity the value of any series resistor may be adjusted up or down to suit.
It could be replaced with an 8 ohm tweeter provided the tweeter's series capacitor of value 4.5 uF is changed to 2.2 uF
Here's a possible replacement tweeter: https://www.visaton.de/sites/default/files/dd_product/TW 6 NG_1000.pdf
If there is a difference in tweeter sensitivity the value of any series resistor may be adjusted up or down to suit.
Here's another 8 ohm replacement possibility: https://www.simplyspeakers.com/replacement-speaker-tweeter-t-125.html
@6thplanet happened to have a pair of 146056 4 ohm tweeters (see attachment) which he passed on to another Bose 401 renovator.
I doubt if he has a second pair in his possession!
@6thplanet happened to have a pair of 146056 4 ohm tweeters (see attachment) which he passed on to another Bose 401 renovator.
I doubt if he has a second pair in his possession!
Attachments
Those look the very thing!
If they turn out to be too loud, put a low value ceramic resistor in series with the tweeter - I'm thinking around 1.5 ohm.
If they turn out to be too loud, put a low value ceramic resistor in series with the tweeter - I'm thinking around 1.5 ohm.
No, don't do that! Always use a voltage divider since changing the impedance shifts the crossover frequency.
I presume this to be a 6 dB/octave, single capacitor filter, in which case the shift will not be of great consequence.
EDIT: I am correct regarding the crossover.
EDIT: I am correct regarding the crossover.
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If he adds the 1,5 Ohm resistor then it is an impedance change! So no, use a voltage divider instead of a series resistor.
5 uF capacitor, 0.5 ohm resistor and 0.5 ohm lamp (or, in early runs, a second lamp in place of the 0.5 ohm resistor).
OR, 4.5 uF capacitor, 1.0 ohm resistor and 0.5 ohm lamp.
May I take it that there is just one lamp in your version of the crossover?
Is it an electrolytic capacitor or a plastic film capacitor? (Bose used plastic film in the 301 Series II speakers I renovated.)
