"Don Pearce" wrote


That is part of the art of speaker design. You start with the
theoretically correct values, then juggle them to make them work with
the real world impedances. Then you do a sensitivity analysis - that
is sensitivity of the design to variations in speaker and component
tolerance. Then you do a yield analysis to see how many will arrive
within spec, then you centre the design so that even if it isn't
perfect at nominal impedances, as a many as possible will pass spec.

That is why it is only the professionals who can afford to make many
models and even more measurements will ever be good at producing
decent speakers.



The word 'professional' is a little misleading here - many classic
'homebrew' speakers are actually designs from highly capable and highly
qualified people, many of whom I am sure did not design speakers for a
living. It is also, I feel, a little unfair to suggest that well-known,
established designs didn't benefit from proper design and development
processes - I can't throw examples up without a lot of searching, but I am
aware that it is fairly common that many successful designs will have been
evolved over a great period of time, using sophisticated equipment
(including anechoic chambers) and undergone many refining processes such as
you describe. Then there is also the great likelihood of a raft of feedback
and improvement suggestions from a considerable number of people who will
have built a standard design and gone on to experiment with it - all the
(non professional) home builder has to do is be able to build strictly to
the design...!!

Speakers, like other 'homebrew products' also benefit from the freedom from
the constraints of cost-effectiveness and financial viability of
professionally/commercially produced items where, as we all know, much of
the component cost goes into the cosmetics. There is nothing cheap about
homebrew speakers, even if one is prepared to cost the comparatively
considerable effort of building them at nothing. What you do get, if you are
lucky, is a speaker that might well not have been too cheap to build, but
would have certainly cost a great deal more if it had been a commercial
product.

Mass-produced/commercial speakers will always offer more bang for your buck
and look better (if 'audio furniture' is your thing), but there is nothing
quite like the moment a box you have bashed together in your workshop
actually *speaks* to you for the first time - which is of course when they
will sound their worst, but it is better still when they continue to hold up
after a period of brutally honest comparison with available commercial
products!! :-)

(Having just done it, I can't think why on earth I bothered to type all of
that...??)