The
Robin-II is outstanding when supported with subwoofers.
As stand alone speakers, they are too dry for my liking.
The
Robin-IIa is designed to be used without subwoofers. In
this version, midbass is now more pronounced. In "Love
Will Keep Us Alive" (Eagles - Hell freezes Over),
the bass tracks are loud and punchy. Vocals are still
clearly discernible, not muffled by the bass. When "Money
for Nothing" (Best of Dire Straits) came on, the
drums are fast and the highs don't sound like screeching
glass.
Fig
9 below show the changes made to the network. The new
Inductor and Capacitor for the M5a midwoofer forces an
earlier roll-off, increasing the apparent loudness of
the bass in the process. In the Mini Elliptical tweeter,
the Lpad was adjusted lightly for marginally higher SPL.
To retain the presence in the vocals, the LCR network
was removed. Distortion test of the Mini tweeter showed
no induced distortion without the LCR (Fig 10).