AH-204

The standard AH-204 has a mouth diameter of 800mm, with a throat of 170 mm (+/- as required) giving an axial length of 310mm.  The Le Cléac’h flare rate is 204Hz at 0.8 T factor calculated from a 168mm throat size.

A version with mouth diameter of 650mm can be made.

Horns can be made with throat sizes down to 1.4” for compression drivers or smaller cone drivers. Pls note:  The prototype mould has been scrapped and a new mould is under construction.

AH-204 Frequency Response Plots (Yamaha)

AH-204 Frequency Response Plots (TAD2001)

AH-340

The AH-340 has a mouth diameter of 600mm and an axial length of 405mm to a 1” throat. The horn sports the complete Le Cléac’h flare back.  Throat sizes can be made from 1” to 2”, or larger, if required.

The Le Cléac’h flare rate is 340Hz at 0.8 T factor calculated from a 1.5” throat size.
 
AZ-340s have been used with a variety of drivers, including Vitavox S2 (original commission), JBL 2420, Yamaha JA6681B, TAD 2001 and 4001, Selenium and even a Yamaha dome mid range driver.

AH-340 Frequency Response Plots (Rank)

AH-340 Frequency Response Plots (TAD2001)

AH-340 Frequency Response Plots (JBL2420)

AH-550

The AH-550 has a mouth diameter of 300 mm and an axial length of 205mm to a 1” throat.  Throat sizes can be made from 1” to 2” or larger.

The Le Cléac’h flare rate is 550Hz at 0.8 T factor, calculated from a 1” throat size.

The AZ-550 was commissioned for Vitavox S2s.

AH-550 Frequency Response Plots (JBL2420)

AH-160 Mark 2

The 160 was the original Azurahorn, now available again from an accurate new mould. The Mark II 160 was commissioned for a RCA 1428 compression driver and can be made with throat sizes down to 1.4”. This is a large horn with 950mm mouth. Full length is 1024mm to a 1.4” throat.  When made for Lowthers with throat diameter of 175mm, the axial length is 450mm. 

The Le Cléac’h flare rate is 160Hz at 0.8 T factor calculated from a 1.5” throat size.

AH-160 Response Plots (LowtherMP2A)

AH-160 Response Plots (Yamaha)

AH-160 Response Plots (Rank)

AH-50  Bass horn

The ABH-50 is a 50Hz L-shape bass horn with a mouth area of 7700 sq cm proportioned to the Golden Mean. Throat diameter is 170mm and overall length 2.3m. The expansion is 48Hz / 0.6 Hypex calculated using David McBean’s HornResp.

The L-shape configuration limits folding to a single 90 degree bend and provides support for the mid horn.

The plywood floor section is straightforward to construct, and the triangular footprint suits corner placement. 

 AH-50 Frequency Response Plots (Lowther)

AH-50 Frequency Response Plots (Seas)

 Plans are avaliable here

Push–Pull Bass Horns

Push–Pull bass horns can be implemented in two variants: Both share the same expansion as the AH-50.

AH-PP1

AH-PP1 consists of 2 x fibreglass rear sections joined to a plywood floor section. (basically a  AH-50 bent over) and utilizes the 160 front horn.

Plans are avaliable here

AH-PP2

AH-PP2 consists of all plywood rear sections.  Horns pictured have rear sections turned from solid Teak, but a square ply section can be used, or fibreglass. The ABH2 is a challenging project, with many angles requiring accurate cutting.

The AH-PP2 utilizes the AH204 front horn.

Plans are avaliable here