Speaker Building With a CNC Machine

[Poultrygeist]

Percision cutting is perhaps the hardest part of any DIY speaker build. I have a friend who has access to a CNC milling machine like the one below and I hope to have him make the cuts for a pair of Frugel-Horn Mk3 which use the new Fostex FE126En. I don't have the link for these free plans but I'll find it and post it later.

http://www.youtube.com/watch?v=mWnM9U9R27A

[Poultrygeist]

Here are the plans for the Frugal-Horn Mk3 - Ask PoppaC how good these puppies sound

http://homepage.mac.com/tlinespeaker...Doc-251010.pdf

[Poultrygeist]

Yipes! The CNC routered Frugal Horn flat packs will be cut this weekend. I hope the DIY gods look favorably on this humble undertaking.

[atomicAdam]

can't you just make that box out of wood? why you going the YG route?

[Poultrygeist]

The CNC routered flat packs will be 3/4 inch MDF which IMO sounds better than plywood and is a heck of a lot cheaper. All the plywood I see these days is full of voids.

It's hell to get a finish on MDF but who knows maybe I'll learn to veneer.

[atomicAdam]

I didn't know a CNC could be used on wood - I always saw them being used on aluminium. But I suppose there are all kind of things I've not seen yet.

[Poultrygeist]

I would think many commercial speaker companies use CNC machines since the cuts never deviate from one run to another. My dentist has one that mills a perfect crown ever time :-)

I picked up my Frugal Horn flats today from a guy who does huge contracts for kitchen cabs and who happens to be a vintage Klipsch fanatic. He said he stored all the settings for the FH cuts in case they sound good. He also said he'd veneer mine once I get them together. If you can believe the huge thread at DIY Audio the Mark 3's are gonna be special.

I was surprised at how small and dainty the FH will be but everything seems small compared to my towering OB's and those heavy assed Omens. Adam, watch out moving those OD's around cause hernias ain't no picnic.

[atomicAdam]

I would think many commercial speaker companies use CNC machines since the cuts never deviate from one run to another. My dentist has one that mills a perfect crown ever time :-)

I picked up my Frugal Horn flats today from a guy who does huge contracts for kitchen cabs and who happens to be a vintage Klipsch fanatic. He said he stored all the settings for the FH cuts in case they sound good. He also said he'd veneer mine once I get them together. If you can believe the huge thread at DIY Audio the Mark 3's are gonna be special.

I was surprised at how small and dainty the FH will be but everything seems small compared to my towering OB's and those heavy assed Omens. Adam, watch out moving those OD's around cause hernias ain't no picnic.

This is true - I found a good amount of foot under the box will help. Honestly - so far - if you like the sound of the Omen Defs - my only complaint is the box. I think the finish is easy to damage and it is difficult to find a place to grab them for positioning.

[Poultrygeist]

The Frugal Horn Mk3 build is on hold as Madisound's Fostex drivers are on back order.

[atomicAdam]

Well blow me down! That is sweet looking!

I totally curious how it will sound when you are finished. How much is this costing you? And when can I get a demo set to review?

[Poultrygeist]

The flat packs for two speakers including a sheet of 3/4 MDF and CNC routing came to $120. The Fostex FE126En drivers cost $43 each. So I'm looking at around $200 which ain't bad considering commercially made back loaded horns can fetch $800+ with the same Fostex drivers and IMO won't sound any better.

I've got some trim cutting and gluing left to do. Plus stuffing the V with acoustifil and gluing batting/cotton felt around the cut outs and on the rear of the magnets.

The drivers won't get here for another 3 weeks so by then I should have everything ready for them to just drop in.

[Poultrygeist]

Here is the rear view of the Frugal Horn Mk3.

[Hyfi]

I didn't know a CNC could be used on wood - I always saw them being used on aluminium. But I suppose there are all kind of things I've not seen yet.

Just think of a Computer controlled Router and you just imagined a CNC machine. I have machined all kinds of materials from metals to plastics to wood in my past life as a Toolmaker. As long as you have the right tool and run the correct RPM and feeds, it will machine wood as if it was metal.

And yes, probably all speaker MFGs use CNC, which just stands for Compterized Numeric Control, for making the cabinets and speaker cutouts in todays world.

Cool speakers being made here for sure.

[atomicAdam]

Just think of a Computer controlled Router and you just imagined a CNC machine. I have machined all kinds of materials from metals to plastics to wood in my past life as a Toolmaker. As long as you have the right tool and run the correct RPM and feeds, it will machine wood as if it was metal.

And yes, probably all speaker MFGs use CNC, which just stands for Compterized Numeric Control, for making the cabinets and speaker cutouts in todays world.

Cool speakers being made here for sure.

I hear you - I've just only seen CNC in use on metals and plastics. Just figured wood was done by hand. But......

[Poultrygeist]

I believe there's a video on the Zu website that shows a CNC machine routing speaker cabinets from MDF.

[atomicAdam]

I believe there's a video on the Zu website that shows a CNC machine routing speaker cabinets from MDF.

Yes I suppose you are correct.

I saw that video at the debut at THE SHOW this year. I don't think any of the Zu guys had seen it either so I got to watch their video and reaction to it. It was pretty fun. Should have had some shots... hummmm....

[Poultrygeist]

Hope to have the Frugal Horn's internals gluded up this week. I'm actually making an extra pair for a friend. The acoustistuff from Parts Express should arrive this week but the Fostex drivers are still on back order.

[Poultrygeist]

Everything is glued up now and the seams are Bondo'ed. Waiting on the drivers. I'll probably start a new thread with before, during and after shots of the build.

[atomicAdam]

Everything is glued up now and the seams are Bondo'ed. Waiting on the drivers. I'll probably start a new thread with before, during and after shots of the build.

I'm getting the build bug too - except I just looked under my car and oil appears to till be leaking out of the spot I paid $300 to fix last week. YAY - spending cash go bye bye.

[Dual-500]

Accurate cuts are one part of the equation - the other is assembly. It takes a skilled hand to "Get it right".

Seems you have a handle in it for sure.

Nice project.

[Poultrygeist]

Got the drivers today, installed the binding posts, hook up wire, cotton felt, and acoustistuff. Clamped the sides together for a brief listen and they sound better than I ever could have imagined. Stay tuned for a new thread and some pictures.

[swan24]

Very neat speakers... I've done some woodworking / finishing, and the best way short of veneering to finish MDF is to spray [not brush] a shellac sealer on the exterior first... A few coats are in order to really seal the pores... Then you can topcoat with a finish of your choice... I personally like a spattered paint finish, which is also sprayed on... Looks professional in all respects... One thing I'd watch out for is where the butted edges meet and are exposed to the exterior... These should be filled with some kind of non-cracking wood filler, then sanded well before sealing... (m.)

[Poultrygeist]

Using auto body filler ( Bondo ) to fill all seams and sanding flush - when finished the seams shouldn't show. Will be spraying several primer and finish coats ( black ) hopefully this weekend.

[daveuzuk]

The CNC routered flat packs will be 3/4 inch MDF which IMO sounds better than plywood and is a heck of a lot cheaper. All the plywood I see these days is full of voids.

It's hell to get a finish on MDF but who knows maybe I'll learn to veneer.

Prime it - sand it - undercoat it (automotive) - wet and dry it - spray paint it (get the spray shop to do it) two pack.

You can do it any car paint colour you like and have a finish as good as your car (automobile).

[atomicAdam]

Prime it - sand it - undercoat it (automotive) - wet and dry it - spray paint it (get the spray shop to do it) two pack.

You can do it any car paint colour you like and have a finish as good as your car (automobile).

I thought you were gonna bust out a daftpunk version of painting some speakers! Dang..