I’ve always been uncomfortable with the Dayton DA270-8 woofer. I tried it in a ported and sealed box but to no avail. While it does deliver on the low bass, the upper bass is disappointing. There’s simply not enough clarity and definition from 90Hz-125Hz. I view this region more important than the low bass of 50Hz-40Hz for it is in the upper bass that the bulk of bass resides. Lose this and all you get is the THUD, THUD, THUD of the bass.
The Albatross addresses this deficiency head-on. It leverages on the unique properties of a bandpass enclosure to tighten the upper bass and yet retain the lower bass. The reason it’s able to do this is because the forces acting on the cone of the woofer is different from that of a direct radiating enclosure of which ported and sealed boxes are.
Albatross 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 Albatross. Even with the steep roll-off, I can still hear the midrange when I tested it out. The Blue plot is with a 24dB/oct Linkwitz Riley electronic crossover set to 300Hz. This eliminates completely the midrange. The Red plot is with the crossover at 150Hz. It is virtually the same after 400Hz. The difference is a steeper slope of about 30dB/oct.
Albatross Building Plans
Fig 2 – Material = 3/4″ MDF/Plywood
Compared to the Crow, the Albatross is rather large, coming in at 75 liters. The Dayton DA270-8 is mounted in the traditional position, that is with the front of the cone firing into the ported chamber. Note the reversed polarity wiring. This is necessary so that the Albatross bass is in phase with the satellite woofers. The -3dB bandwidth is 35Hz ~ 95Hz.
July 22, 2018Projects