Ah, ok. I didn't realize it was a hack job! That picture you put up looks pretty good..
KEF 104.2 Lacking Bass
- Thread starter bane.oh
- Start date
Get yourself a AA battery and a short piece of speaker wire, color coded preferably. Touch the + terminal of the battery to the wire going to the positive terminal of the speaker, and the same with the - terminal. You will hear a click from the speaker. Do this several times and watch what the woofers do through the large port. You may need a small mirror to see the upper woofer. It may also be helpful to have an assistant do the thing with the battery.
What you should see is the lower woofer cone move upwards when the battery is connected, and the upper one move downwards. Or vice versa. What they shouldn't do is both move up or both move down. Report back with your findings.
Lee.
What you should see is the lower woofer cone move upwards when the battery is connected, and the upper one move downwards. Or vice versa. What they shouldn't do is both move up or both move down. Report back with your findings.
Lee.
If you pay attention to Leesonic and can do what he suggests you will get it sorted out.
bane.oh
Active Member
No f'n way. You are a genius my friend. I did what you said and sure enough, on the speaker lacking bass the woofers move in the same direction! I swear I checked all the connections when I had it open the other day. Is there another way a speaker could be out of phase without just crossing the wires? Should I just swap the connections on the PCB? I tested the working speaker and both woofers push "in" when I connect the battery but on the malfunctioning one the bottom woofer moves down along with the top one. By the power of deduction I believe the bottom woofer to be out of phase. How do I fix this?
Thank you!
bane.oh
Active Member
AH! That explains it! So I just have to swap the terminals on the PCB?
Give it a try, perhaps the lower woofer is also wired with "normal" polarity.
Also you can do the battery test to see whether the cone sucks in or pushes out to id the wiring sequence.
bane.oh
Active Member
IT WORKED!
Still curious how the wiring got messed up. but WOW! BASS! I missed you so much. Baba O' Riley here I come!
Thanks for all your help sorting this out, gentlemen. I'll report back again on how they sound after the re-cap.
I can't say enough how helpful everyone on this forum has been. Thank you for being patient with me, I know I am a total noob.
Cheers!
Still curious how the wiring got messed up. but WOW! BASS! I missed you so much. Baba O' Riley here I come!
Thanks for all your help sorting this out, gentlemen. I'll report back again on how they sound after the re-cap.
I can't say enough how helpful everyone on this forum has been. Thank you for being patient with me, I know I am a total noob.
Cheers!
What a great idea and simple trick. Somebody suggested that to me 40 years ago to make sure I wired the speakers in a car. I'd completely forgotten about it.
Glad it revealed the problem
I bought a pair of Kef 104/2's that were a basket case about 11 years ago. I didn't really know what I was getting and never should have purchased them. The paper cones were actually torn. AK members "BrassTeacher" and "GordonW" worked on them together and salvaged them. At that point in time they recommended leaving the crossovers alone.
About a year ago I took them apart and sent the crossovers to Lee and he replaced the caps with ones he got from Falcon. The finished product sings. They should be good for another 20-30 years
absolve2525
Super Member
Very informative thread! I'm glad that the OP got it sorted out. Makes me wonder if I have my woofers wired properly... It's been a while since I did my donuts and ferrofluid. Are the wires distinctly marked for reverse polarity on the one woofer? I had my woofers out when i was working on them, but didn't touch the crossovers. I suppose I will just have to do the battery test mentioned above.
bane.oh
Active Member
I am still a little confused by this because I don't think I should have to plug the - in to the + terminal and vice versa. I guess the PO soldered the wires on the bottom woofer to the appropriate terminals, but if I understand correctly they are supposed to be reversed? So to compensate I switched the terminals on the crossover. Still not sure it's right, but it works.
He must have. The wiring to driver polarity is positive to positive, negative to negative on mine. Mine are the early, single terminal, rubber surround version FWIW.
bane.oh
Active Member
Okay guys. I really need to figure this out.
I "fixed" the bass on the right channel by reversing the spade connectors on the crossover so the (-) on the bottom woofer is connected to the (+) and vice versa. This fixed the polarity problem and corrected the speakers firing out of phase. What I expected to find when I opened the left speaker was the top woofer wired in reverse as some here has told me is the correct way to wire the top woofer. This did not happen. When I opened the left speaker, both the top and bottom woofer are wired (+) to (+) and (-) to (-) and the left speaker appears to be working correctly.
Why do I have to reverse the polarity on the bottom woofer in the right speaker in order to get them to fire correctly??? Is the wiring on the crossover screwed up? What is going on? I am at a loss. I am fairly certain I shouldn't have to plug the spade connectors in to the "wrong" terminals on the crossover in order to correct a phase issue. Help!
I am sending the crossovers out to be re-capped so I can't really do a lot of testing right now. Is there something specific I should ask my guy?
Thanks in advance.
I "fixed" the bass on the right channel by reversing the spade connectors on the crossover so the (-) on the bottom woofer is connected to the (+) and vice versa. This fixed the polarity problem and corrected the speakers firing out of phase. What I expected to find when I opened the left speaker was the top woofer wired in reverse as some here has told me is the correct way to wire the top woofer. This did not happen. When I opened the left speaker, both the top and bottom woofer are wired (+) to (+) and (-) to (-) and the left speaker appears to be working correctly.
Why do I have to reverse the polarity on the bottom woofer in the right speaker in order to get them to fire correctly??? Is the wiring on the crossover screwed up? What is going on? I am at a loss. I am fairly certain I shouldn't have to plug the spade connectors in to the "wrong" terminals on the crossover in order to correct a phase issue. Help!
I am sending the crossovers out to be re-capped so I can't really do a lot of testing right now. Is there something specific I should ask my guy?
Thanks in advance.
I guess it's possible that the little red sticker that indicates the positive terminal may have been stuck in the wrong place. Thoughts?
Sorry I should have posted. Yes it looks like it's on the other side from where mine all are.
