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Toucan-DA The Toucan-DA is my 3rd attempt at using an 8″ woofer for a bandpass sub. While the Toucan-SF met my expectations, the Silver Flute W20RC38-08 cost more than this Dayton DA215-8 which I’m testing. Hopefully, this DA215-8 will be just as good.
Fig 1 is the WINISD modelling of the Dayton DA215-8 in the same 25 liters Toucan box. Port tuning is the same as for the Toucan-SF. According to the simulation, there is a slight emphasis at 50Hz. For convenience, I left it as it is. If this ends up objectionable during audition, I will retune the response for flat.
Fig 2 is the response of the Toucan-DA with the microphone at the mouth of the port. As is predicted in the simulation, there is a bump at 50Hz. I actually prefer this over a flat response because for pop music, the stronger low bass enhances the listening experience. As in all bandpass designs, the upper midrange and treble are not totally filtered out. They start to appear at 600Hz, peaking at 1.5kHz, after which they roll off. For best performance, these unwanted frequencies should be removed.
Fig 3 shows how well the response is cleaned up with a 24dB/oct electronic crossover. Even when I set the crossover as high as 500Hz, it is still able to remove all the “dirt” (Black plot).
Fig 4 shows the effects of a 24dB/oct Lintwitz/Riley crossover on the passband. At 500Hz (Black plot) and 250Hz (Blue plot), there is not much difference from the RAW passband. However, at 150Hz (Red plot), we see the passband drooping downwards, For best response, I recommend crossing the Toucan-DA at 250Hz.
Fig 5 is the building plans for the Toucan-DA. I lined the upper sealed chamber with R-13 fiberglass insulation and left the lower ported chamber bare. I find the bass sounds better with this arrangement. Lastly, I wired the woofer in the opposite phase. This will cause the bass emitting from the port to be in absolute phase. It doesn’t mean that it will sum properly with a satellite. A spectrum analyzer should be used to check on the integration of any subs with the satellites in use. Toucan-DA vs Toucan-SFBoth may be 8″ woofers but they don’t sound exactly the same. The Silver Flute Toucan-SF exhibits some texture and bass details that’s lacking in the Toucan-DA. It is impossible to tell unless an AB comparison is carried out. It doesn’t mean the Toucan-DA is bad. Not at all. Unless one is highly critical of bass quality, the Toucan-DA would suffice for most listeners. Toucan-DA vs Crow-IIWhen pitted against the Crow-II, the difference is more dramatic. The Toucan-DA has more “body” and a slightly deeper bass. The Crow-II on the other hand, is more neutral and has a faster attack. Headroom on the Toucan-DA is higher than the Crow-II by virtue of a larger woofer. It can easily fill a room with bass whereas the Crow-II will hit max unless two units are used. I would recommend the Toucan-DA for music like the Eagles. For vocals like Diana Krall, the Crow-II is a better choice. I find bass that’s a bit too strong distracting when I’m listening to voices. This of course, reflects my personal preference. It’s up to the user to choose whichever one that suits his taste. |
September 20, 2020HIFI DRIVERS, Projects
Fig 1 – Toucan-DA Bandpass Model (WINISD)
Fig 2 – Toucan-DA RAW Response.
Fig 3 – Frequency Response plots at 500Hz, 250Hz, 150Hz, 125Hz and 90Hz
Fig 4 – Recommended Crossover Frequencies
Fig 5 – Toucan-DA Dimensions