help needed with old Celef speaker x-over please

edited September 2011 in Loudspeakers
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hi folks,

can anyone tell me which of the Celef speakers these are, the chap that
gave me them said they had Celef badges on the covers (sadly thrown
away) , there are no sticky labels on the back either,

the cross over boards were falcon acoustics pcb 8 but they have been
badly messed with at some point , when i got the speakers they sounded
horrid , a quick check of the response with a phone app shows 12db lift
from 200hz downwards and 12db lift from 8khz upwards leaving a concave
trough across the midrange response ,

running them with just a cap in series with the tweeter has shown that
the drivers are in fine fettle (almighty peak at 1khz from the b200
included ! )

in the second picture i have done a wee doodle of a crossover , the low
pass should be fine as is ,it utilizes the standard notch filter as
prescribed by kef to attenuate the afore mentioned 1khz peak , from
there its a simple 2nd order 12db oct slope set to around 2.5khz which
should keep the old driver well below its upper break up point ,

what i am wondering is what value of inductor and capacitor should i go
for to use the new seas tweeters that i have chosen as they are the
closest current equivalent , the old seas h211 was a good tweeter but i
cannot find a data sheet or printed response for it ,so have decided to
replace them with the 27tff ,

any help would be much appreciated,

best regards

matt

Comments

  • http://www.linear.com/designtools/software/#LTspice

    Try this Matt simple and easy to use gives good results
    They look like old IMF speakers 
    col
  • thankyou Col, will give that a go, had a dig through a box in the shed and found some 0.32mh inductors and 8mfd 100v polyprop caps , stuck them into a simple second order  circuit and padded it down ,
    using an app on my phone with a few test tones i think i may have got lucky , if the phone app is to be trusted the response is within 4db from 200hz - 12khz with only a tiny lift at around 9khz , cant check the resistance curve but the dcr of the system is 8.1ohm so the old Claymore wont get flustered,
     soundwise they are so easy on the ear, not going to set the world alight but surprising none the less,
    thanks again for the link,
    best regs,
    matt
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