A-290 Wood Horn

Yellowstone National Park, WY, USA (Photo by Yuichi)

A-300E Specifications

= Horn Type : Exponential horn
= Cut-off frequency : 300Hz
= Frequency range : 600Hz to 20KHz
= Driver : 2 in or 5 cm throat (Pioneer TAD 400x or JBL 244x or
equivalent drivers)
= Size : W 623mm, H 190mm, D 359mm (incl. 24mm throat adapter)
= Material : a Cherry plywood (7.0 cm thickness) for horn body
....a Cherry plywood for side walls '2.5cm thickness)
....an Ebony for fins (internal separators)
= Finish : Two coats of oil based clear polyurethane varnish

= Color : Not applied
= Others
- Four fins are inside the horn



...Sept. 1985 MJ Magazine....
Building and assembly process

Transfer template on a plywood by pencil. Cutting of the plywood by
a hand circular saw / very
tough work !!/
Cutting out of side horn
curve by a drill / tough
work, too !!/
Rough forming by a hand
electric saw
Coarse forming by a
electric plane
Horn curve making by a
electric hand plane
Fine adjustment of contour
by a belt sander
Side curve finalization of
by a belt sander
Fin forming by a belt sander
An Ebony is really hard !!
Assembly process of side
walls
Driver adapter process
Adjustment by a chisel
after 2in hole is made
Surface polish by a rotary
sander


Measurement and Data


Driver : Pioneer TAD 4001
A frequency response and a admittance curve. This combination can be used as a tweeter in 2 way system.
Driver : Pioneer TAD 4001
2nd and 3rd harmonic distortion are shown with +20dB uplifted.
A horizontal characteristics of A-300E horn. 0, + or - 22.5 and + or - 45 degree output are shown. A directivity property does not depend on a driver characteristic.
Driver : JBL 2445
A frequency response and a admittance curve. Smooth output is outstanding character. A super tweeter beyond 10KHz needed
Driver : JBL 2445
2nd and 3rd harmonic distortion are shown with +20dB uplifted. Smaller 3rd harmonics is outstanding.
A vertical characteristics of A-300E horn. 0, + or - 15 degree and + or - 30 output are shown. A directivity property does not depend on a driver characteristic.

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