Introduction

Many years ago I built an ultra-linear tube amplifier, Heath Kit pre amps and speaker cabinets with Electro Voice speakers. I thought those days were gone, but then my son sent me a picture of a horn speaker enclosure saying here is your next project.

The picture my son sent.

 That got me searching the Web and there was the Frugel Horn FH3 using a 4" driver which looks like a great project and maybe some great sound. I wonder what "In the Wake of the Wind" will sound like.

From the DIYAudio forum, Frugel Horn Mk3-paks

Some months ago I started the design of a CNC router and before I got very far into the project it was clear that my shop was a disorganized mess. I started by building a lot of storage, mainly wall cabinet and specialized cabinet for my power tools, drill press, miter saw, etc. At this time I am completing a router table and cabinet all of which can be found on my workshop projects blog, see links. One thing my shop needs is some great sound, before I get back to the CNC router project.


Documentation:
             http://homepage.mac.com/tlinespeakers/FH/beta/frugel-hornMk3-1v0b-300911.pdf

Sources:



Drivers:

1. Fostex FE126En, 4.7", 8 ohms, Fs=83 hz, Qts=.3, Vas=.3, $50. from Madisound
2. MarkAudio CHP-70.2, 8 ohms, 4", Fs=72.3 hz, Qts=0.52, Vas= 4.7L, $36. from Madisound
3. MarkAudio CHR-70.3, 8 ohms, $36, from Madisound
4. Tang Band W4-1879, 4", 8 ohms, Fs=55, Qts=0.43, Vas=9.1L, $60. from Parts Express
5. CSS EL-70, 4", 4 ohms, Fs=64, Qts=0.55, Vas=6.1L, $39 Creative Sound Solutions

So far 10 different drivers have been test in the Mk3 and discussed on the DIYAudio forum. I posted a question concerning the musicality of these different speakers with a recommendation of the EL-70 by Planet10. The EL-70's have a 4 ohm voice coil and since I will use these Mk3 with a Pioneer 50 watt receiver, the EL-70 may overload the amplifier. For the initial build we will use the CHP-70.2. If you are looking for great bass try the W4-1879.

Materials and Parts:

The material cost including drivers should be less than $150. for a pair of Mk3's. Though the development builds are done with baltic plywood, which I do not have access to, we will use the cabinet grade plywood from HD. I have built several cabinets with this plywood which is great plywood and void free. As an alternative the Lowes Blonde 18mm (23/32") plywood could be used.