Frugel-Horn Mk3 Builds & Build Questions

I've had my pair going for a few months now so it's about time I posted some pics and feedback.

Although I did all the stuffing as per instructions and post #424, with the removable lid I ended up taking all stuffing from the front chamber so it's left looking like my first pic here. I dont find it's too boomy at all, the bass now matches the mid/highs just nicely. In saying that, they are not in the perfect listening position just now. I'll soon be moving them to my back room where they'll be sitting a good distance from the wall and nicely in a corner. This may require some stuffing placed back in, but thats why I made the top removable hay :)

I'd recommend the method I used for the top lid removal. One M6 bolt into a self tapping timber thread insert. You need to do a bit of sanding till the lid fits snugly, but then it's access in seconds. I used self adhesive foam strip designed for door draft sealing to form a gasket. If you glue a "gate" of stuffing across the base you can just drop in or remove stuffing quickly and easily (you do need to remove the driver first of course).

I was going to make some feet coming out for the floor spikes but ran out of time. They're very steady with them just fixed to the four corners how it is.

I spent a lot of time modifying the original dxf for use with 18mm ply that retains all internal dimensions as drawn. It’s for a cnc router but could be used for hand cutting too. If anyone would like a copy just pm me.

Thanks heaps to the developers of these little beauties, both for the design and knowledge plus all the "after sale service". I spend more time listening to them now than my Sonus Fabers.
 

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Thanks Planet10. Now I just have to decide if I'll build based on the 126 or if I'll do some measurements and start to experiment. :)


do you already have the FE166E on hand, or in transit?

if so a BIB would likely be the simplest - for which I'm sure the math has been done; for a more advanced build and arguably more nuanced performance, the Woden Victor or Olson / Nagaoka manifold (Haruna) would be worth a look

based on several builds of similar designs, I'd imagine the former would be an easier build (if my part count is right, there's 38 pieces per box for the manifolds)
 
do you already have the FE166E on hand, or in transit?

if so a BIB would likely be the simplest - for which I'm sure the math has been done; for a more advanced build and arguably more nuanced performance, the Woden Victor or Olson / Nagaoka manifold (Haruna) would be worth a look

based on several builds of similar designs, I'd imagine the former would be an easier build (if my part count is right, there's 38 pieces per box for the manifolds)


No, I am still planning things out, but I liked the spec on that driver (especially for the price) - it seems to give a lot more on the bottom end while still being Back loaded horn friendly.

I was initially planning on making some Voigt pipes with the 166's, but these folded horn designs are fun, and my wife liked the look of the Frugal horns... (which is as good as saying I can make them - it's a bonus that it is a simple build).

I'm wondering now If I can flop the design to have a front horn flange, and scale it up to fit the quarter wave length of the 166 and put a super tweeter on top with a passive crossover... but I need to do the math.

I did really like the Hiro design, but it's a more complicated build than I want to take on at the present. What is the BIB (edit - ah, found it. Still pretty tall... and I'm not sure about the top opening flange, but interesting.)
 
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No, I am still planning things out, but I liked the spec on that driver (especially for the price) - it seems to give a lot more on the bottom end while still being Back loaded horn friendly.

I was initially planning on making some Voigt pipes with the 166's, but these folded horn designs are fun, and my wife liked the look of the Frugal horns... (which is as good as saying I can make them - it's a bonus that it is a simple build).

I'm wondering now If I can flop the design to have a front horn flange, and scale it up to fit the quarter wave length of the 166 and put a super tweeter on top with a passive crossover... but I need to do the math.

I did really like the Hiro design, but it's a more complicated build than I want to take on at the present. What is the BIB?



BIB is acronym for "Bigger Is Better" - the term coined by our late friend Terry Cain

Single Driver Website

Essentially it's a long path QTWP with internal fold, and generally top firing full aperture for boundary ( i.e. ceiling ) reinforcement.

I heard a pair of Terry's BIBs at an audio fair in Silverdale in 2001 - very impressive with the FE164E(?) at the time.

Construction is very simple, although there is of course some math involved in determining the CSA / path length and driver location. At one time Jeff (Godzilla) had a website devoted to the design which included calcs for a pretty wide range of drivers, including I'm sure the FE166E. No doubt someone has either a measured plan or at least the specs cached away somewhere.

As I tend to constrain my own builds to either something that I'm sure would pass the SAF ( Sue acceptance factor ) which these don't, or as a prototype for a small commercial venture, I just never got around to building a pair.


Another design that might work would be the Metronome

The Metronome


edit: As to the question of "scaling" or modifying enclosures of this family - by all means have at it - either by fluke or careful calculation your results might work well

personally I don't find the 166 needs a tweeter, but there's certainly no harm in accommodating for that in the aesthetic and construction
 
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MK3 build using one side sanded plywood

I am about to build two MK3's using Home Depot Cabinet grade plywood at $29 a sheet. I have not been able to find Baltic plywood locally. The HD plywood is void free and great stuff which I have used to build several shop cabinets. Lowes Blonde wood could also be used but it does have some small voids.

One problem I noticed was the cut sheets from the document for 18mm plywood assumed both sides sanded. I have attached a new cut sheet to solve this problem and also to ease the transport of the plywood in a car.
 

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Error on FH3 cut sheets

I assume that sheet FH3-2 is correct. This drawing shows the back 1 1/2" above the base. If this is true then on cut sheet C-3 the back should be 32 11/16" not 31 7/8" and the internal should be 29 3/4" not 29 1/16". To see that this is true assume the back is perpendicular to the base, then 34" - 31 7/8"= 2 1/8" which is larger than 1 1/2".

All the cut sheets appear to be wrong, unless 1 1/2" is wrong
 
Whoops, I see my problem. The cut sheet dimensions assume an added piece at the ends of back and internal parts as on sheet FH3-5. My dimensions are correct if the construction is done to match the FH3-2 drawing, that is, just rounding over the end of the back and internal pieces.

I bought the HD 18mm cabinet grade plywood for $29. and transport in a Chev Cavalier was easy. I am modifying my cut sheet slightly and will post soon. On my cut sheet all pieces except the internal has vertical grain.
 
frugal-phile™
Joined 2001
Paid Member
Thanks for that.

As it turns out, C3 (& C4) are cut sheets for FH3-2 in the previous iteration when the join at the bottom as was originally configured (as per the middle method on sheet FH3-5) -- which i see you caught already.

I have updated C3 &C4 to reflect the current FH3-2 and will post a link to an updated drawing set shortly after adding a few other updates.

dave