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Loudspeaker Designs and Articles for the DIY Enthusiast
The
Singularities
A high sensitivity / high SPL
design offered for Music
Applications
Contour Network:

No crossover needed for  a single driver, but even the best full range drivers need a
little help to provide a reasonably flat in room response. The Contour network shown
below compensates for the rising response caused by the transitions from 4pi space
to 2pi space.

The optional impedance normalization network is highly recommended for tube
amplification, but unnecessary for solid state devices.  

Because of the potential current flow through the resistors, and the resultant power
dissipation, I recommended 2 parallel resistors (a 25 ohm paralleled with a 30 ohm)
and suggest they be at least 10 watts. With so few components, you can splurge on
a couple of those Vishay-Dale, or Alcol Gold aluminum bodied resistors you've
always wanted to try.
Links to:

Main / Design Goals

Driver Selection

Cabinet Construction

Crossover Design

Measurements

Listening Impressions