| larrellio |
i am rebuilding some 1972' jensen 4-ways for my boss.
i replaced most of the drivers with comparable units from partsexpress. but there is one part i am having trouble replaceing because i dont know what its called or what it is.
the boxes have one-15", sub one-8"woofer, one-3.5"mid
and two-silk dome tweeters.
AND TWO NOBS-the mistery parts.
one of the nobs. one is labeled mid frequency, and the other is labeled high frequency,
one of the boxes the nobs work fine, turn up the high and the tweeters get louder, turn up the mid and the mids get louder.
but on the other boxes(there are 4 of them) the frequency adjustment nobs are smoked, i took one of them out(i kliped its wires off without labeling them and caused my self to cuss, then puzzle it out useing the other intact box as an example) and opened it up and found that its parts are burned up and blackened.
hummm frequency adjustment nob...... perhaps i have just answerd my qwestion for my self.....will check it out.
i will post a picture as soon as the batery on the camara charges.
your help and gidance is greatly apreiceated.
LAR |
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| rpapps |
Hi larrellio
I'm thinking wire wound potentiometers but will wait for the pictures to verify. Can you read any numbers off them or are they too badly burned? Alternatively read them from the working unit.
Cheers
Rob |
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| larrellio |
bah, i cant figure out how to put a picture inti this reply.
i am trying though................. |
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| flg |
I will second that mike.m216:D :D :D : You probably need to maintain the impeadance during adjustment or a change in the frequiency characteristics will result. The output of the pad will be a varying of the power to that speaker...
Picture's are generally worth thousands of word though... |
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| larrellio |
well i cant get my digital camra to take pictures that agr less than 690Kb, and thats over the limit, so i will search the parts websites for the produtcs that u have sugested and see if they look like what im after, thanks for the help, rob and mike. : )
LAR |
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| larrellio |
L-pads, for sure!
thanks folks!
this site rocks! |
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| AndrewT |
Hi,
adjustable Lpads that can take speaker power are likely to be expensive.
Measure the Lpad that is working to find the resistor ratio you like the sound of.
Buy fixed power resistors to mimic the Lpad setting and have a listen.
You may find the fixed resistors sound even nicer than the adjustable and end up making all the speakers fixed. |
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| flg |
| 5 Watt units are common. But the natural attenuation of the upper end makes that fine for the tweet. Getting to low into the mid can be a problem. Fixed resistors, good idea! |
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