When a woofer, midrange, or tweeter fails, it is time to replace (or repair )
it. Exact replacements are a necessity in this case. If the left side tweeter is
not working and you can get an exact brand and model number replacement
then do it! If the replacement is of the same brand (but not model number) do
not waste your time or money. Non-exact replacement mids and tweeters will "fill
the hole" but not give you the sound of the original. If a non exact replacement
part is used, you will not only have to replace the damaged part but
both drivers to keep a balanced stereo image. As previously stated,
crossovers were designed for the original drivers and any compensation that was
added might not sound good on the new drivers.
All crossovers (passive or electronic) are not rigid frequency dividing
lines. In a simple two way design (one woofer and one tweeter) the designer
might set a crossover point of 2000 hertz (also written as 2 Khz or 2000 cycles
per second (cps)). This does not mean that all of the energy
above 2000 hz goes to the tweeter and below it goes to the woofer. In fact, in
some low budget designs, there is no upper frequency roll off for the woofer.
This means that for at least one octave of sound above and
below this frequency (1 Khz to 4 Khz) the sound from the two drivers will
intermingle and cause interference. This can be either constructive or
destructive interference and the designer takes this into account by knowing not
just the response curves of each driver but how they work together. If the
woofer and tweeter both have a peak of 3 dB at the same frequency, they could
combine at this one band of frequencies to make the sound "harsh" (like the
sound through a megaphone). Conversely, if the speakers cancelled each other,
you would lose many of the important midrange frequencies making the sound a lot
quieter, thinner and less present. This is why I would not recommend clone
replacement mids and tweeters in a quality speaker system.
The woofer, should it fail, is the most critical component to replace as it
works in conjunction with the cabinet. If you haven't already, I urge you to
read my importance of box tuning sub page.
