Dylanl Posted October 1, 2004 Share Posted October 1, 2004 I just received my 2 new woofers (K33's) from Klipsch. Before I had 1 driver 2 - 2 1/2 db higher than the other. Now that the new ones are installed they are dead even on my spl meter. Is it more important to have matching drivers or 2 drivers that push out more db's? Will I loose bass response, gain or loose now that both match? Also is there a break-in period to the K-33? Thanks Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 1, 2004 Share Posted October 1, 2004 What do you mean by dead? I liked my K33E's from the first minute I had them in... DM Quote Link to comment Share on other sites More sharing options...
Dylanl Posted October 1, 2004 Author Share Posted October 1, 2004 They are even as far as output is all I meant. Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 1, 2004 Share Posted October 1, 2004 While somewhat obvious, I'd say that it is best to have two which meet spec. It does seem that something went out of spec on one of your original ones. However, without careful testing, we'll really not know with any certainty. I wouldn't be too surpised if the problem was not with the driver but rather with a connection or an air leak in the mounting or the hatch. Not that I'm saying that happened, or to cast any doubt on your trouble shooting ability. It is just that sometimes replacing parts in any electro mechanical system solves an unrecognized problem. It is one of the headaches of troubleshooting anything. E.g. I heard that dust was an unrecognized problem in some UHS transmitters. The old tubes tested good, but replacing them fixed the problem of weak output. Then they'd work okay in other transmitters. We've had a lot of traffic about break in. I've read at least one reputable source (Joe D'Apolito) who says the OEM people say the parameters do shift after some use. I think they are talking hours, not days or months. I tested some Pyramid 15 inch drivers with very good equipment and found no shift after 12 hours of hard driving at resonance. Maybe they broke in during the first test which took a minute. That is actually quite a few flexings. I'm very sceptical about claims that use of speakers for months will change their output. I'd love to see any sound curves to substantiate this. We do get used to the sound of any system over time and I think that accounts for it. Congrats on your work. It must have been a bear. Now you're an "expert". People will call on you for advice. Smile! Gil Quote Link to comment Share on other sites More sharing options...
Dylanl Posted October 1, 2004 Author Share Posted October 1, 2004 I agree with you. I wish I knew exactly why 1 was hot vs. the other. I detailed everthing that I did and all clues pointed to the driver. Switching from 1 cabinet to another the problem followed. I used the same crossover same wires same channel and that channel was on mono not stereo. Is there any outside test that could show a drivers output? If I could test outside the bass bin I think it would show if something was going on in the voice coil. Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 1, 2004 Share Posted October 1, 2004 The problem, in my view, is that partial driver failure is rare. Usually the voice coil (VC) wires or the "tinsel" leading from the electical terminals to the VC, burn out. It becomes an open circuit . . and the speaker is dead. There ARE partial breakdowns though. Sometimes the heat from hard driving softens and distorts the varnish or plastic holding the VC wires to the "former". The latter is the cylindrical bobben which the wire is wound upon. As you may know, the VC and former sit in the narrow gap of the magnet structure. Also, the structure of the driver can "bottom out" when driven too hard and the structure hits the metal of the magnet. The resulting sound is a clanking. Hard to believe a woofer can make that sort of noise. But it does. So there can be pure mechanical destruction from over excursion. But maybe there is softened plastic which adds to the issue. In any event, there can be a loss of output because of mechancial binding of distorted components in the gap without a total burn out. You should check the old units for mechanical binding. You can put spread fingers on the diaphragm and push it 1/8th inch. If there is a mechanical problem, this touch test may show up a difference between the two. The bad one will feel gritty, hung up, or stiff compared to a good one. You can check voice coil resistance of both with an ohm meter. I've never tried it, but maybe the resistance will change with the push test on a bad one. Gil Quote Link to comment Share on other sites More sharing options...
Dylanl Posted October 1, 2004 Author Share Posted October 1, 2004 Now that I think about it the gasket on the new K33 is much thicker than the original. Klipsch uses lag screws to hold the woofer to the motor board. This does not do the greatest job of making an air tight seal. I think the screw should go all the way through w/ bolt and lock washers. Tom Mobley also had a good idea "to caulk the woofer bin" to eliminate any chance of air loss. I am also thinking of caulking the bass bin door. Quote Link to comment Share on other sites More sharing options...
ricktate Posted October 2, 2004 Share Posted October 2, 2004 I think the gasket on the bass bin door is the least of your worries...in my redoing of my Ks i found air leaks that are alot worse than the gasket on the door could ever be.I sealed and glued the seems on the inside of my bass bins they are pretty airtight now, The way i tested this was i sealed up the woofer slot with piece of wood and rubber gasket,,,then put the bass bin door on except for one screw that went into the airtight chamber.I applied compressed air into te screw hole then its easy to hear or feel the leaks,,,,if its pretty airtight air will come back out screw hole when you remove the air hose...Rick Quote Link to comment Share on other sites More sharing options...
Dylanl Posted October 2, 2004 Author Share Posted October 2, 2004 Rick, what did you use to seal the bin? I want to do this. Quote Link to comment Share on other sites More sharing options...
ricktate Posted October 2, 2004 Share Posted October 2, 2004 I used glue on the big cracks i could see...then spread silicone on all the inside joints to,,,,easy to do. I got mine so airtight now the woofer acess door buldges out when air is applied. A little air still escapes but nothing like it was believe me lol.Im still working on redoing mine so not sure how they sound but im sure the leaks were not good, Rick P.S. a couple of joints where i couldnt reach or see i just poured glue in there and later i saw it run out into the horn throat so it was very big gap there Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 5, 2004 Share Posted October 5, 2004 If the problem follows with swapping the driver to/from different cabinet, then it's not an air leak problem. The voice coil impedance of each should be checked and should be the same. If so, then I would suspect the magnet, one driver having a more powerful magnet than the other (compliance is not going to be the problem, either). This has a direct effect on excursion and therefore sensitivity. But I would question the environment, being that 2 new K33Es would also exhibit the same behavior as the "old" ones. This is an unlikely event. DM Quote Link to comment Share on other sites More sharing options...
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