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CYNR

CB-10 crossovers

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Hello good people:

Just finished replacing the capacitor and resistors on my CB-10s as part of my refurbishing project.

some pictures before and  after. Not a complex XO but the first i've done.

The original XO had three different looking resistors (not values) 

and the new ones I ordered from Solen's sent me three different also

one Bennic (made in Taiwan) ,one made in Taiwan (no name) and one unbranded???

Part one can be seen here...and below the before and after of my xo's

Lonny


 

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I always like to see 5w resistors replaced with 10w although some members claim this is unnecessary. I've seen burned 5w resistors in KLH speakers so I take no chances.

That yellow cap is mylar and probably good but the new Solen is nice.

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Hello Kent:

I had to change the yellow cap from a 5uf to a 5.1uf , still inside the +- 5% .

I spent a few hours burning a few songs into my head so I could compare the sound before and after

but I really can't hear any difference, but now I know they are new, It has been a fun project and way easier and

cheaper than restoring a 1968 Oldsmobile 442 convertible.I am still looking for a decent amp to power these.

Lonny

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On 9/4/2020 at 12:11 PM, CYNR said:

but now I know they are new, It has been a fun project and way easier and cheaper than restoring a 1968 Oldsmobile 442 convertible

Yes--good hobby that provides fun and satisfaction. Good luck with the 442!

Amp choices are endless. The original ads say these work fine with low power amps. Judging by your avatar I'm guessing you're in the Great White North. If I were there I might be looking for a nice used Bryston but that may be overkill.

Kent

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Hello good people:

I am having a little trouble understanding the diagram of the crossover, if someone could please explain to me why

the Terminal 2 GND. goes to the NEG. on the woofer and the POS. on the tweeter, also what does the 7.5 ohm resistor do???

and  what do switch terminals No. 5 and 7 connect to ?? I should have payed more attention when I had these apart.

Thanks in advance for helping ...

singed, Confused in Canada.

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Weird that no one saw this post, any info about the diagram above and my questions would help me in understanding 

a little more about these speakers.

Thanks

Lonny

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The tweeter is wired out of phase to the woofer. Why? The designer determined that the speaker sounded better at the crossover point by shifting the tweeter phase. It may be that the the phase angle between the two drivers was sufficient at the crossover point that wiring the tweeter out of phase made for a flatter response at the crossover.

The 7.5 ohm resistor forms a portion of a voltage divider circuit with the other resistors. With the switch in the illustrated "Decrease" position, the voltage divider is a 3 ohm equivalent resistance and a 7.5 ohm resistance. Moving the switch to Flat or Increase reduces the 3 ohm equivalent resistance and increases the resistance of the lower portion of the voltage divider, resulting in a higher voltage applied to the tweeter and less attenuation.

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RTally you are the best.

I was not sure about the tweeter being out of phase or a typo on the sheet, but I get it.

as for the 7.5 ohm resistor I see it  now, I can look at the diagram and see the flow .

As I stated in another post they did not teach speaker impedance and crossovers in my diesel mechanics classes.

Thanks

Lonny

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