Hi,
so i have a Bose series 1 from 1982, they are not working.
I would like to restore as new, it 's completed moulded in plastic, i will have to open it anyway.
Can you help me to remake the crossover for my pairs of speakers.
I did not find the electronic diagram on internet. Bose is even not responding to any inquiries.
As i know you are all professionals, i just need help from you if it’s possible.
Thank you very much.
.
Start by taking out the original and making a list of the components and specs:
from the ebay listing below its super simple.
1 cap
1 resistor
The cap will most certainly be off-spec but you can measure it (the meter will cost more than a new cap 
)
Resistors are inexpensive but might not require replacement
Before you go into the crossovers, how are the drivers?
here is one for a series II: Original Crossover For Bose 201 Series II Bookshelf Direct | eBay
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Thank you for your suggestion,
i will start to check each part of the crossover.
Drivers are not ok.
I think i can find similar not Bose of course or maybe in ebay.:
6 inch 15.2cm woofer
2 inch 5.1cm high sensitivity tweeter
impedance = 8 ohms
crossover transition freq: 1,5Khz and 2,5Khz
60 Watts max
10 Watts min
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You could have a lot of fun with something like a Behringer DCX2496 (a very cheap Loudspeaker Management System with six internal dacs that allow crossover and EQ). This would allow you to get some very cheap amps to power the drivers actively 3-way per channel. You’d end up with active speakers that you can EQ to sound good in your room.
i watched the YouTube in French about it.
Too complicated for me for now.
I will start slowly step by step.
Hi @ErVikingo,
i opened the speaker and i found this:
resistance of tweeter = 6.5 ohms
resistantce of woofer = 6 ohms
They seem fine, not really damaged.
will have to test them.
The filter has a resistance (looks like a resistance): 2 homs
There is condensor: 2 UFJ 100dvc
It looks like that one in ebay:
I just tested speakers they are working fine, so i will order 2 crossover and i will poste here the result.
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The series II capacitor (condensor) is not the same value as yours, therefore the crossover frequency will be different. I would presume this was done by Bose because they probably used different drivers in series II. I’m not certain what the glass tube device is, but my guess is it’s a power limiting device and it may be damaged. It seems to have a filament like an incandescent light, and if so, it would increase resistance as power is increased. This would protect the drivers from too much power and back in those days low cost amplifiers (very common) distorted badly when turned up too high. Personally, I would buy the bare parts from a speaker parts supplier, and solder them in place. I recommend film capacitors (non-polarized) and a good option is Solen.
I would not try to replace the glass tube device and just be careful with the music volume.
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I would like to replace all components and test it.
Yes i know the Bose 201 series 2 is not the same and the filter won’t be the same.
i did not find for the Bose 201 serie 1
I did not find something like a coil or thungstene, please show mw in the picture.
Sorry, I’m not sure what you are asking. Inside the glass tube it appears there is a filament, but I’m not sure.
ok i see, my bad i create confusion about the glass tube.
maybe it’s a fuse.
For this condensor, im not sure about the value:
Is it 2 micro farad 100VDC
i can’t find the serie 2UFJ
i sent an email to Solen with the image.
Hi,
so i received the condenser, the tweeter fuse and the resistance.
can someone tell me if the output negative and positive are correct?
please see the image,
It works, so i close this thread.
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