Silver Flute W17RC38-08 with Waveguide
13 Liters Bass Reflex Satellite

by Michael Chua

This design is free for DIY. Not for Commercial Use.
This article may not be published in part or full without the express permission of AmpsLab.

Pellegrene Waveguide at 2kHz

The Canary-II explores the behaviour of the Waveguide at a lower crossover frequency. Instead of crossing at 2.5kHz, the revised crossover is at 2.0kHz (12dB/oct).

Fig 10 shows the comparative plots of the Raw waveguide (Black trace), the waveguide at 2.5kHz (Red trace) and lastly at the new fc of 2.0kHz (Blue trace). All traces are normalized to the 2.0kHz crossover.

Fig 10 - Vifa XT25TG30 with Waveguide Frequency Responses
(mic 1 meter Tweeter Axis | 5ms Impulse Window | 1/12 oct smoothing)


XT25TG30 + Waveguide + XO

Fig 11 is the Distortion plot of the XT25TG30/Waveguide combo with a 2.0kHz, 12dB/oct filter. Remarkably, there are no signs of induced distortions brought about by the lower fc. The bulk of the distortion originates from 2nd harmonics (Red trace).

Fig 11 - XT25TG30 + Waveguide
2.0kHz 12dB/oct passive XO (NO LCR)
(mic 20 ins On Axis with XT25TG30 | 5ms Impulse Window | 1/12 oct smoothing)


Canary-II Frequency Response

Fig 12 is the Frequency Response of the Canary-II. Due to room limitations, measurements below 500Hz should be disregarded.

The Canary-II crosses acoustically at 2.0kHz. Summation is as good as can be in the crossover region.

Fig 12 - Canary-II Frequency Response
(mic 1 meter Tweeter Axis | 5ms Impulse Window | 1/12 oct smoothing)
(fc=2.0kHz | Low Pass 18dB/oct | High Pass 12dB/oct)


Canary-II Distortion

Fig 13 is the Distortion plot of the Canary-II. The XT25TG30 with the Waveguide is completely clean. The distortion peaks at 1kHz and 1.7kHz are from the Silver Flute W17RC38-08 midwoofer. These distortions are inaudible in music playback.

Fig 13 - Canary-II Distortion
(mic 20 ins On Axis with Tweeter | 5ms Impulse Window | 1/12 oct smoothing)


Canary-II Impedance & Phase

The Canary-II Impedance and Phase is similar to her predecessor. The minimum impedance is only 8 ohms at about 1.5kHz. Phase angle is within +/- 18° from 200Hz-20kHz. At box port tuning (57Hz), the impedance is 14 ohms with a Phase angle of -9°. The majority of power amplifiers will not encounter any issues driving the Canary-II.

Fig 14 - Canary-II Impedance & Phase Response


Canary-II Crossover Network

Fig 15 - Crossover Network of CANARY-II

the sound of Canary-II

The Canary-II differs from the Canary primarily in the midrange. Vocals are more forward and distinct. The Canary-II sounds marvellous when supported with subwoofers.

next > Canary | Canary-II

Sep 22, 2013


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