The Toucan is a compact 25 Liters Bandpass Subwoofer based on an 8″ Dayton SD215A-88 DVC Subwoofer. I tested the SD215A in a Bass Relfex and a Sealed Box before and I found the bass blurry. However, when I loaded into a Bandpass enclosure, the SD215A produced the dynamics and definition that I’m after.
Toucan Frequency Response
Fig 1 – Measurements taken with the mic at the mouth of the port.
The Black plot in Fig 1 is the RAW response of the Toucan made with the SD215A-88 voice coils wired in parallel. The Blue plot is with an active Low Pass filter at 250Hz (24dB/oct Linkwitz Riley). The Red plot is at 125Hz and the Violet is at 95Hz. Note that the internal resonance from 1kHz~4kHz is completely eliminated when the bandpass is low passed. I displaced the RAW response by +10dB for a clearer view.
During auditioning, I was rather surprised to hear the distinctive “clack” of the Dayton SD215A-88 voice coil former hitting the back plate. What troubles me is I wasn’t playing loud. This is the first time I’ve ever come across a woofer that bottoms out so easily.
I duly went to my electronic crossover and activated a 25Hz High Pass Filter. And like magic, the problem disappeared. In fact, the bass definition improved.
December 25, 2018Projects