Kamis, 29 Januari 2009
Check your Loudspeaker Crossover
It was last week, when I brought my 'analogue arsenal' to my Dad's home. He want to listen to old vinyls he discovered lately in the house. All set up, all LP's cleaned (washed to be exact), put an LP from Tony Bennett..this great guy voice's sounds great..but why is the right speaker sound more pronounced?..aah..the old Technics left tweeter did not work..why?..
Took the box home and off the grill, ups..the woofer dust cap did not look right, off then with the tweeter, the mid (it is a 3 ways system) and the crossover. Checked the tweeter with a multimeter, yup..it's dead all right. Those cheapo crossover !, they use a very cheap bipolar electrolytic capacitor (small cylindrical thing). They have a limited life, and when it did went bad even the speaker protector can not do anything. There goes the culprit, and I have replaced it with two quality film capacitors, now you'll have extra 10-15 years of listening pleasures.
So, please check your 'expensive' JBL's, Bose's, Sony's, Phillipses, etc. If you see this kind of capacitor, replace them immediately with film type, the same value of uF and same or higher Voltage of course. Do this before your tweeter goes in to smoke, and if you planned to go the DIY way make sure the warranty time is out.
When I took off many parts of the speaker (it's an old Japan design), I have noticed that I have to use 2 types of screw drivers, found many types of screws, each different in size and form..what??..
In term of mechanical design, this is a BAD design practice. Too many parts, too many items, one too many tool, way to many part bins during assembly, storage, purchasing-inventory management..on and on..(you get the drift..).
I have counted 6 types, plus another 2 on the crossover assembly, oh yeah, another one on the speaker protection PCB in total : 9 types of screws. This is too expensive. Is Technics still around this day?
Thanks for reading