What ohm woofer? Puzzle!

[boo3000]

Hi, i have a pair of speakers that i bought missing woofers for a repair job, this turned out to be more difficult than i thought as the company which made the speakers won't tell me exactly which woofers were used in these speakers! To work it out i need to find out what resistance the original woofers were, the speakers have a nominal impedence of 8 ohms, the tweeters have nom/mini impedence of 8/6.3 ohms, judging by this schematic can anyone tell me what impedence my replacement drivers should be?

http://www.krksys.com/documents/9000b_schematic.pdf

Any help greatly appreciated!
Thanks
Justin

 

[macboy]

If the speaker is nominally 8 ohms, then the woofer is nominally 8 ohms too.

 

[head_unit]

I hate to be the first to tell you this, but it's not that simple. The woofer, tweeter, and crossover are all interdependent, and the crossover is designed for those EXACT tweeters and woofers. If you wanted the speakers to sound the same, you would really need the exact same woofer. Sticking some other woofers in there might work OK or might sound awful.

Can't you order the exact replacement woofers?

You might get more responses if a moderator changed the thread title. I'm not sure to what, but "What woofers to put in KRK 9000b cabinets?" or such.
- Are the speakers indeed KRK 9000b?

 

[boo3000]

Hi, yes it is a krk 9000b that i need a replacement woofer for, the problem is that the original woofer was made by cabasse, and krk no longer deal with them. Krk are telling me that the original woofer was a 21m18lb4 but when i check this with cabasse there were a few variations of this woofer made, some 4, some 8 and some 16 ohm. So if i can just figure out the resistance of the original woofer i can get some replacements on the second hand market. Is it possible to calculate the resistance from this schematic?

 

[sreten]

Hi,

0.7mH on the bass mid unit is consistent with an 8ohm unit with no BSC.
With a 4 ohm unit the speaker would have to be nominally 4ohms.
The 16 ohm units I'd say were only used in pairs.

rgds, sreten.