4345 Project

[Ian Mackenzie]

Hi have sent an email to Marty for an update

Hopefully we might see some images of the system installed.


I have a sister system (using the 2123H) and intend to fit a Tad 4001 driver with the 2311/2308. Aftermarket Be diaphragms maybe an option for those interested but the passive filters will need modification. I have Leap V, Sound Easy and LMS so its not that difficult.

Pending how it goes I may also mess with some other ideas like conical horn loading the 2123 to enable time alignment of the mid cone.The 2123 loads up very well on a suitable horn.

Still in the works is a dedicated class A active crossover using a double sided pcb.

[Ian Mackenzie]

As a post project idea I have ordered an eliptical wave guide XT 1086 to experiment with the effectiveness of constant directivity.

One of my pet hates with the 2307/2308 is the non linear directivity at higher frequencies . Attempts to toe in the enclsure for more balanced on axis response does not work. I figure if this idea works for me some others in diy mode may also consider it .

The XT 1086 is a wave - guide of elliptical design and produces a spherical wave front with low distortion. The size of the wave - guide also has some practal benefits

Previously I have used the 2344 100 x 100 bi radial with v.good results. Perhaps the only down side was the wider than required 100 x 100 dispersion

The XT 108 has constant directivity 80 H x 60 V from 1.4 to 16 K hertz and with a crossover point of around 1.5 khertz it should match the directivity of the 2123H(according to Rob's 2123 simulation)

The XT1086 will initally be trialled atop the 4345 box but if its promising I may install it in place of the 2307/2308.


http://www.eighteensound.com/index.a...roduct&pid=178

[pos]

Why not use a rectangular PT waveguide? The apparent dimension would be similar to a 2307/2308

[Ian Mackenzie]

Why not use a rectangular PT waveguide? The apparent dimension would be similar to a 2307/2308

This is a 1 inch throat wave guide

I don't have a 1.5 inch throat driver..I mean if a JBL 0476 was avaialble I would be using it