7B / 7C Tweeter difference?

blueridge
blueridge Posts: 6
edited April 2002 in Technical/Setup
Since I didnt get a response to my earlier question, I'll try again. I was trying to find the differences between the 80s Monitor 7B and 7Cs. I did a little research and see from the parts page on this site that the only parts difference is the tweeter. Frequency resp. for both speakers is 26-25K, but I see the 7C was 4ohms, the 7B 8.

The parts page shows:
the 7B had the SL1000 tweeter,
the 7C (except fpr 84/85 models) have the SL2000 tweeter.

Can anyone (maybe someone from Polk) comment on that the differences are between these two tweeters- if one is sonically better than the other?

Any help with this would be much appreciated.

thanks-

b
Post edited by blueridge on
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Comments

  • joe logston
    joe logston Posts: 882
    edited March 2002
    i would go with the 8 ohm driver. to be safe , im not sure what the crossover you have if it is a two way that runs two drivers at 4ohms 4+4 = 8 ohms, you got to look at the crossrover if it runs two drivers in parallel or series.
    . rt-7 mains
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  • nascarmann
    nascarmann Posts: 1,464
    edited March 2002
    b,
    I have one of my old catalogs out and it shows the Monitor 7C's Nominal Impedance as 6 ohm. I can't find a catalog with the 7B's in it. As far as the difference in the 1000 and 2000 tweeter I'm really not sure. But the 2000 was the upgrade of the 1000 and was used in the SDA series and 10B's. Then the SDA TL models upgraded again to the SL3000. So one would imagine the SL2000 is the better tweeter than the 1000, but I can only say this without first hand knowledge. I'm sure this probably wasn't much help :o
    Oh, the bottle has been to me, my closes friend, my worse enemy!
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  • blueridge
    blueridge Posts: 6
    edited March 2002
    thanks Joe for the reply.

    actually, i dont need to replace anything, i just cant remember whether the change from the 7B to 7C was sonically better or not - and since I see the tweeter was the only difference, i was just curious if newer tweeter was an improvement or not.

    cheers

    b
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  • nascarmann
    nascarmann Posts: 1,464
    edited March 2002
    I have one of my old catalogs out and it shows the Monitor 7C's Nominal Impedance as 6 ohm

    Well, found another old catalog showing the 7C'c Impedance 4 ohm. WOW! :confused:
    Oh, the bottle has been to me, my closes friend, my worse enemy!
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  • blueridge
    blueridge Posts: 6
    edited March 2002
    n-

    that's what i thought too (6 ohms) but the actual manuals i have for both show the 7C with 4 ohms (maybe a misprint) and the 7Bs at 8 ???

    wonder if i could upgrade my 7Bs to the newer SL2000 tweeters? they may eventually be the surrounds to my CRS+s main speakers so it would be nice if the tweeters matched.
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  • nascarmann
    nascarmann Posts: 1,464
    edited March 2002
    Not sure, but I would think there would be no problem!
    Oh, the bottle has been to me, my closes friend, my worse enemy!
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  • blueridge
    blueridge Posts: 6
    edited March 2002
    i'll send Polk support an e-mail and see what they think

    thanks
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  • joe logston
    joe logston Posts: 882
    edited April 2002
    its in your cross over that would make a differance if a singal crossover is runing two driversyou need 4ohm drivers your receiver is 8 ohm resistants at the cross over your drivers are in series so 4 ohm + 4ohm= 8 ohm or 4ohm + 8ohm = 12ohm, its how your crossover is you mite have two cross overs one per driver or two on one bored network what is the mid rangewoofer driver ohms are.
    . rt-7 mains
    rt-20p surounds
    cs-400i front center
    cs-350 ls rear center
    2 energy take 5, efects
    2- psw-650 , subs
    1- 15" audiosource sub

    lets all go to the next ces.
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  • nascarmann
    nascarmann Posts: 1,464
    edited April 2002
    The x-overs are the same in the B & C's
    Oh, the bottle has been to me, my closes friend, my worse enemy!
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  • joe logston
    joe logston Posts: 882
    edited April 2002
    i dont know what to tell you . it must be a factory up grade where they thougt that the 4ohm drivers where better and they went with it on the latter modals of polk.a driver is not fix at a certain ohm they take the average, average of a 4ohm is 2 to 6 ohms or 8 ohms is 6 to 10 ohms. the drivers are not fixed.
    . rt-7 mains
    rt-20p surounds
    cs-400i front center
    cs-350 ls rear center
    2 energy take 5, efects
    2- psw-650 , subs
    1- 15" audiosource sub

    lets all go to the next ces.
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