Bose 601 Series III Speakers

amplifiers, receivers and loudspeakers
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mark79
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Bose 601 Series III Speakers

Post by mark79 » 05 Dec 2019 15:33

Hello All: I acquired a pair of Bose 601 IIIs that were made in 1986. The woofers were dry rotted but all of the tweeters were working. The crossovers were weird-I have never seen that before including the resistor. I gutted those-removing all the packing and the cardboard tubing-dropped a pair of Dayton Classic Woofers in and changed that capacitor to Dayton 2.7uf 250V. I tried 2.2uf that was a little off, then went back to 2.7uf. Those speakers really sound great with a lot of deep bass with a high end that is smooth. I also lined the inside back with packing just enough to catch any boominess. I didn't overspend on the woofers until I heard the results. To my ears, they sound great. Any comments would be appreciated. I thought that if I ruined them it wouldn't be too much of a loss to the way they were before. I left everything else in the crossovers alone. I didn't take out the resistor-it had something to do with the tweeters and I didn't want to change that. Regards; Mark79

PioneerFan
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Re: Bose 601 Series III Speakers

Post by PioneerFan » 05 Dec 2019 16:45

If you enjoy how they sound, that is all that matters. I don't think there really is a "right or wrong". Amar Bose was a master experimenter and tinkerer, and would likely approve of your work.

mark79
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Re: Bose 601 Series III Speakers

Post by mark79 » 06 Dec 2019 00:13

Thank-You very much PioneerFan: That capacitor that seems to go to the tweeters originally a 2
.4 uf 100V. Right now I've got a Dayton 2.7uf 250 audio cap. in but also have the same thing at 2
2 uf 250V. Would the 2.2 be too much? The original ones that were in there looked cheap. Regards; Mark79

PioneerFan
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Re: Bose 601 Series III Speakers

Post by PioneerFan » 06 Dec 2019 13:22

Not sure- but experimentation is what this hobby is all about. It sounds like you're doing it in a fun way. A

Alec124c41
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Re: Bose 601 Series III Speakers

Post by Alec124c41 » 09 Dec 2019 15:00

IIRC the 601 had an array of tweeters that should give you great ambience.
Those resistors would be to balance the output of the tweeters to the output of the woofers.
If it all sounds good to you, it is good.

Cheers,
Alec

TudorTurtle
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Re: Bose 601 Series III Speakers

Post by TudorTurtle » 14 Dec 2019 13:55

Mark, I can't hear the difference between a 2.2 ohm and a 2.4 ohm resistor in a tweeter XO. Usually doesn't show up in frequency response measurements either.
BTW, there are quite a few Freq Resp apps for mobile phones that can help find big drop-outs or humps. Parts Express has a inexpensive mic to gild the lily. Won't replace a pro audio analyzer but is very helpful.

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