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Bozak E-300 Century

The tweeters I have are the ones in the B-207-b woofer. They are B-200-y and say 8ohms on them.

The mids are out of the tower and are B209bc with a sticker that says 16ohms. So wiring two 16 ohm speakers in series will give me 8ohms? I am new at this and appreciate all the help.
 
arranb said:
The tweeters I have are the ones in the B-207-b woofer. They are B-200-y and say 8ohms on them.
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OK, you're fine there unless something has happened to one of them. Any post-X variant of the B200 is pretty sturdy, though. Typically when they were wired as pairs from the factory, they labeled the impedance of the pair, not the individual drivers.

The mids are out of the tower and are B209bc with a sticker that says 16ohms. So wiring two 16 ohm speakers in series will give me 8ohms? I am new at this and appreciate all the help.
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Actually, that would give you 32 ohms impedance. Parallel wiring would give you 8 ohm impedance.

http://www.bcae1.com/spkrmlti.htm

arranb said:
I googled this and found that the Mids in this b302a are the same number as the ones I have. The B209bc. Is this the same thing? Is this a different speaker?


http://smg.photobucket.com/user/Mok...eaker Internals/DSCN0126.jpg.html?sort=3&o=10
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Any Bozak driver with a lowercase "c" appended to the end of the model number indicates that it's a ceramic magnet driver instead of Alnico. They made the switch sometime in 1970 or very early 1971. Brian might know for sure.

Bozak made multiple impedance versions of the same driver for different configurations. There are 16 and even 32 (and I think 4) ohm B199s out there. I know there are 8 and 16 ohm B209s, and possibly a 4.
 
Here is what I received in the mail today for one of the cross overs. Is there any particular way I should arrange them on the board? Also should I wrap the coils in something? Sorry for the questions most of you know the answers to as this is my first. Thanks
 

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arranb said:
Here is what I received in the mail today for one of the cross overs. Is there any particular way I should arrange them on the board? Also should I wrap the coils in something? Sorry for the questions most of you know the answers to as this is my first. Thanks
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Coils should be perpendicular and away from each other. Other than that, make the layout simple as possible.
 
Hey
somewhere on here there is a picture of a x-over someone built. I'm not very good at looking stuff up but I have seen it here When I was doing mine.sorry not much help but that's all I got. Eric
 
The B450s are much smaller than the B209s. They're good drivers in their own right, but they probably don't get down far enough to meet a properly crossed-over B199.
 
Sam I need your help. I just bought the b-450c's on ebay today thinking they would be what i need. I really wanna upgrade my e300's. I bought all the stuff for the crossovers but can't seem to find the correct speakers. The 16 ohm speakers won't work and I'm guessing neither will the b450c's. Do you have any you'd like to sell? I really appreciate the help.
 
I don't have any spare stuff that would help you out. I got lucky and found a set of ugly but functional 8 ohm B209s on eBay for a price I could justify after about a year and a half of searching.

If you've got the B450s on the way, by all means, give them a shot. You might want to keep the crossover point at the 800Hz used in the original B302 configuration and the Tobin 101T. It's not the ideal point for the B199, but the B450 might get down to meet it. I've never seen a response curve on them.
 
I received the B450's today and they are to small (we already knew that) Is there a way I can use the 16ohm mids out of the towers and just change the crossover a bit? The tower speakers are just sitting collecting dust. Thanks everyone.
 
That sounds about right for the DCR of 8 ohm B209s.

Be aware that these are the paper-cone original B209s, not the later aluminum version. I've had a pair of these for sale in BT for a while. Didn't even think about them off the top of my head, most people want the B209B or B209Bc mids, though the B209 has a bit of an undeserved bad reputation. It's not outright terrible, like the B200X tweeter.
 
The B209 bad rep is a result of Rudy. He truly believed in metal cone drivers and spent his life trying to get them to work. He pooh poohed his paper cone drivers as a result for this goal.

He was right, the aluminum cone mid is better but the paper cone version is not bad by any means, easily as good as most very good paper mids. If the B209 is economical enough, get them.

Have you tried the towers, yet? If not, you really should. You may be pleasantly surprised, very pleasantly.
 
I have hooked up the tower to my sx-1250 but it doesn't seem right because the e-300's can't take as much. What would be the best way to hook up the towers and the e-300's to the same receiver?
 
I have the b209bc but they are 16ohms. Is there a way the crossover can be modified to make them work with the other speakers?
 
arranb said:
I have the b209bc but they are 16ohms. Is there a way the crossover can be modified to make them work with the other speakers?
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Don't worry, that won't prevent success.

Do the math for the parallel resistance and crossover frequency calculations and you'll see it all works out. Impedance mismatches (woofer, mid, tweeter) are common, you take them into account when calculating the RC network value.

Also, as far as the aluminum vs. paper debate, the Bozak Al cones require a latex coating to damp out resonances, and that tends to be degraded to the point of flaking off after all these years. So the performance difference between Al vs paper probably isn't what anyone thinks it is, what it was new, or what Rudy intended.

I've never seen any measurements on the driver differences, either, and would like to know if a practical difference exists. The B-800 mid/full-range driver is reported to be spikey because of cone resonance but, again, I haven't yet measured this. (My Bozak B-305 project is in boxes at the moment, although the cabinet is sitting in my living room saying "finish me!".)
 
Retrovert said:
Don't worry, that won't prevent success.

Do the math for the parallel resistance and crossover frequency calculations and you'll see it all works out. Impedance mismatches (woofer, mid, tweeter) are common, you take them into account when calculating the RC network value.
Click to expand...

Is there a procedure listed on how to make the calculations? I'm learning but this is foreign to me.
 
arranb said:
Is there a procedure listed on how to make the calculations? I'm learning but this is foreign to me.
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Sure. Google "crossover calculator". Plug in your numbers for the driver's impedance, inductor, and desired frequency, solve for capacitor. Or, do it the hard way and keep tweaking the cap value until the frequency comes out right, since everything else is fixed.

Crossovers are just electrical filters. The higher the order, the steeper the slope of the cutoff. The LC circuit determines what frequencies are blocked or passed.

Google will turn up enough explanations to get you where you need to go.
 
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