Kingfisher3 (SuperMicro-DX2 with SF W20RC38 BP-Sub)



The Kingfisher3 is a refinement in the tonal balance of the Kingfisher2. In the previous Kingfinsher2, the Albatross is slightly heavy on the bass. By this, I mean the weight. The THUD, THUD in the bass is quite pronounced. Another point of contention is the Albatross is a 75 liters box. Not everyone has space for two of these. 

This led me to review my bass options. Eventually, I decided to use the Toucan 25 liters box with the Silver Flute W20R38-08 woofer. It came out exactly way I wanted. Gone is the THUD and the bass tightened up considerably.

Silver Flute W20RC38-08 Bandpass SubwooferSILVER FLUTE W20RC38-08 BANDPASS RESPONSE

Fig 1 – Black plot = Dayton DA270. Brown plot = Silver Flute W20RC38-08

Fig 1 is a direct comparison between the Albatross and the new bandpass subwoofer with the Silver Flute W20RC38-08. The two subwoofers were measured with a 2nd order, 250Hz low pass filter attached. This effectively removed all the midrange from bleeding out of the tuning port.

The most glaring difference between the two subwoofers is their bandwidth. The Albatross rolls off at 100Hz whereas the Silver Flute is at 150Hz. At the lower bass, both roll off after 40Hz. 

Kingfisher3 Drivers Frequency ResponsesSILVER FLUTE W20RC38-08 FOUNTEK FE85 PEERLESS DX20BF00-04 FREQUENCY RESPONSE

Fig 2 – Brown plot = Silver Flute W20RC38-08. Blue plot = Fountek FE85. Red plot = Peerless DX20BF00-04

Fig 2 shows the responses of the individual drivers. It may look similar to the Kingfisher2 but sound wise, it’s quite different. I tuned the Kingfisher3 for a flat response. The critical midrange bandwidth from 400Hz~2kHz is virtually flat. 

Another change I made is to the Peerless DX20BF00-04 tweeter. I reduced the high pass filter from a 3rd order to a 2nd order. This will reduce the dipping central lobe that’s in the Kingfisher2. If I want to have the central lobe horizontal, I’ll need to time align the FE85 and the DX20BF00-04.  

Kingfisher3 Frequency ResponseKINGFISHER3 FREQUENCY RESPONSE

Kingfisher2 Frequency ResponseSUMMED RESPONSE DA270 FE85 DX20BF00

Fig 3 – Black plot = Kingfisher3. Blue plot = Kingfisher2

The top plot in Fig 3 is the frequency response of the Kingfisher3. After summing with the Peerless DX20BF00-04 tweeter, the midrange remains flat.

The Kingfisher2 (Blue plot) on the other hand, has a few dB rise from 1kHz~4kHz. This translates to an increase in midrange presence. This has the same effect as electronically equalizing a flat speaker for midrange presence, only that I did it with the crossover. It’s all part of voicing a loudspeaker. 

 What does the Kingfisher3 sound like

Well, the Kingfisher3 sounds like a typical flat response loudspeaker. Some will find it a bit bland, myself included. To inject some life to the music, I added an adjustable midrange presence network. 

KINGFISHER3 MID PRESENCEFig 4 – Kingfisher3 Midrange Presence (Brown plot).

Fig 4 shows the Kingfisher3 with the midrange presence activated (Brown plot). It’s a very light touch, about 1dB from 1kHz~2.5kHz but the effect is like night and day. The Kingfisher3 now comes alive.  

Auditioning the Kingfisher3

What stands out with the Kingfisher3 is super detailed and super clear midrange. Add to that a bass control that is only associated with expensive woofers like my Peerless NE265W, the system is extraordinarily musical. Even at moderately low volume (80dB), I did not need to strain to enjoy my music.

In Santana’s Supernatural album, the growling in The Calling (Track 13) is scary. This begins at the 2:30mins mark. With the guitar playing and supported by the vocal accompaniment, one can easily be transported into a trance like state. While all these are going on, you’re immersed in this subtle earth moving sub-bass.

Bela Fleck and the Flecktones UFO Tofu is an album that’s exceedingly demanding on bass. In Magic Fingers (Track 7), the bass is absolutely bewitching. You feel like you’re being constantly drawn in and kept in captivity to witness the banjo performance.  

Having spend days listening to various genre of music, I am satisfied that the Kingfisher3 has achieved its objective. It took awhile to find the right bass but it’s worth the effort. There’s dynamics, definition and texture. Now the loudspeaker sounds correct. The tempo is lively. The speed adds to the realism. And the tone is natural. Amazing. All with a $10 midrange and a $10 tweeter. Of all the Kingfisher variants, I strongly recommend the Kingfisher3.

Kingfisher3 System

Fig 5 – Suggested Kingfisher3 System

Fig 5 shows one way the Kingfisher3 can be set up. The SuperMicro-DX2 satellite is lifted off the subwoofer so that the tweeter is at the listener’s ear level. A pole or some kind of contraption can be used. If it’s large enough, the crossover can be located there.

The Silver Flute bandpass subwoofer is best placed on the floor with the port at the bottom. For optimum performance, the Kingfisher3 should be 3ft~5ft away from the side and back walls.

Note: Unless otherwise stated, all measurements were made with the mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied.