Copyright 2009 - AM Audio
No duplication of any material without consent.

Adam McCall -
- 4x TangBand W4-657SH Aluminum Mid/Basses
***This driver is no longer availble;
            substitute W4-656SC.

- 1x HiVi RT1C-A Isodynamic Planar Tweeter
- Completely Shielded
- 1st Order External X-over at
        3000Hz w/ Impedance EQ
- 5ohm Nominal Impedance
- 100Watts RMS
- Freq Response 60Hz-20kHz
- 48" x 6" x 12" (Speaker)
- 10" x 6.5" x 4" (X-over)
- 75lbs each
- Slim Design for Tight Spaces
- Solid MDF Construction
- White Latex Painted Finish
Design Notes:
     I came across 8 of the TangBand drivers a while back and this was the result.  At the time I was looking to build a slim speaker for the bedroom that would be very clear and have a full sound.  I was impressed with the mass of the drivers and was expecting some surprises.  Budget was also in mind and I managed to use the natural slopes of the drivers and created a fairly simple 1st order x-over with 2nd order characteristics.  The decision to go external with the x-over was to retain the ability to tweak the x-over if needed and due to the tight space inside the cabinet.
     In conclusion I have to say I am impressed!  These things put out some serious sound; very much an open sound.  The only adjustments I had to make was adding a bit more polyfill to keep the echo effect down and also add a small bit of padding to the tweeter.  It ended up being more sensitive than anticipated.  In a larger room they will need a sub through my experience.  They truly perform in smaller rooms; like my office where they reside since I bought a house.  They are a very unassuming speaker; which certainly isn't a bad thing. Very clear and articulate with a surprisingly good bit of low end. 40Hz is audible even; even though graphical representations indicate a cut-off much earlier. 

Additional Notes:
The plinth pictured in the photos was a personal addition to my speakers.  It is recommended, however will not be found on the drawings.  The external crossover enclosures are a one off item as well, you will have to source your own enclosures when building your own.  I will only build the crossover circuit only; no enclosure unless purchasing a new set.  The crossover can be mounted internally to save cost.
     This design, as well as the original pair of speakers are available for sale (note that the driver used in this speaker is no longer available; a substitution must be made).

Items/Services For Sale:
- Original Opus1 Speaker Pair $1400 (does not include freight; I do have crates already built for these)
- Opus 1 Speaker Pair $1150 ($1300 w/ external xovers) (6-8 week lead time; does not include freight & crating)
- Complete Design Package w/ Drawings, BOM, X-over Schematics  $40
- Crossovers $260/pair  (2-3weeks lead time; includes shipping)
Opus1 - 2way Slim Tower
Photo Gallery
Opus1 CAD Rendering
Measured response - On Axis 11x12 room