"Stevie Boy" wrote in message
...
Over the last few weeks I've kinda got a speaker bug as I've been thinking
about 5.1 systems.
I came across a few sites regarding improvements to SBL/SL2/DBL/IBL range
of crossovers as they are all more or less identical.
As it now looks that I may be using my SBL's to part accomadate home
theatre along with my standard Hi-Fi, I've been chewing on the claims made
of improved sound performance through substituting better components
within the crossover.
I'd like to know on a cost basis if this really is a useful step upwards
for the speakers (rather than spending money elsewhere) & pick peoples
brains of useful tips on the subject.
If anyone has had direct experience to I'm all ears 
**I am unfamiliar with the speakers you mention. However, my experience with
various types of speakers tells me this:
* Electrolytic caps should be replaced. Bipolar electros have a relatively
short life and rather poor characteristics. A caveat, however: Some
manufacturers take the flaws of electros into account and design their
speakers accordingly. Simply replacing electros with film type caps may lead
to other problems.
* Ferrite core inductors are (generally) to be avoided. A suitable air core
inductor will almost always lead to improvements. A further caveat: Ferrite
core inductors can be made small and with low resistance at low cost.
Additionally, leakage flux is less of an issue. If replacing a ferrite
inductor with an air core type, ensure the resistance is the same as the
ferrite one and that it is suitably oriented such that leakage flux does not
interfere with other inductors.
[Anecdote]: A client sent me a sample speaker he was importing from the US
(major, high quality manufacturer), complaining that it didn't sound as good
as expected. After running tests, I noted that the ferrite core inductor was
saturating at a level of 10 Volts RMS @ 50Hz. Replacing the ferrite
inductors with air core types solved the problem. This was, admittedly, a
rare fault, but indicative of what can occur.
* Laminated iron core inductors are much better than ferrite core inductors.
They do not have a 'square law' hysteresis curve and thus do not saturate
nastily. Personally, I would probably not bother replacing laminated iron
core inductors with air core types.
* Solder all connections.
* Cover all internal surfaces with a suitable damping material. I rather
like Bostik Sound Deadening panels. These are used in automotive
applications and are quite reasonably priced.
Trevor Wilson