Hi! I want to build the Mk3 version using CNC and translam design, I have attached a picture with numbered points of interest and I have several questions before I proceed with the design 
any help or input would be valued
1. Does this need to be an edgy point ? (As far as I understood yes, but just making sure)
2. Can I create a smooth curve here instead of an edge ?
3. same question
4. same question
5. Is it entirely possible to shorten the speaker like demonstrated by approx 50mm without harming the sound ?
Doing this translam style means the wall thickness would be very small approx 15mm, the parts might be too gentle after they come out of the CNC. Is it possible to make the plates thicker without harming the internal size ? as demonstrated here ? this would make the speaker heavier and more "dead" but more importantly make it easier to CNC and sturdier, would this be bad in any way ?
any help or input would be valued
1. Does this need to be an edgy point ? (As far as I understood yes, but just making sure)
2. Can I create a smooth curve here instead of an edge ?
3. same question
4. same question
5. Is it entirely possible to shorten the speaker like demonstrated by approx 50mm without harming the sound ?
Doing this translam style means the wall thickness would be very small approx 15mm, the parts might be too gentle after they come out of the CNC. Is it possible to make the plates thicker without harming the internal size ? as demonstrated here ? this would make the speaker heavier and more "dead" but more importantly make it easier to CNC and sturdier, would this be bad in any way ?
While the trans-lam technique can certainly allow for some interesting internal shapes and contours not easily achievable otherwise, I’ve always considered it an inefficient - bordering on obscene - use of material and machining time for sure. Now, with a large enough 3D printer, and the ability to pause fabrication for application of damping fill materials.....
Having built a few pairs of FH3 kits, I’d suggest CNC capability could be put to better use machining the side panels with slightly loose dados for the internal divider and back panels, as well as driver cutouts and perhaps any decorative filigree / inlay work.
Having built a few pairs of FH3 kits, I’d suggest CNC capability could be put to better use machining the side panels with slightly loose dados for the internal divider and back panels, as well as driver cutouts and perhaps any decorative filigree / inlay work.
No.
Not an issue, althou the squared off bit in the inside at the choke point is preferred.
No.
With use of qulity plywood oriented the right way you can easily get away with 15mm. If you are going translam (ie not using the plywood in the direction of its “strength” the walls will need to be something like 2 x as thick. ie 30mm.
I have done that many times as i adjust the design for different material thicknesses, althou i haven’t stretched it out to 30mm+.
Heavier is not an asset unless it brings more stiffness, and by going translam you are throwing away the normal stiffness of plywood. In this case, one would have to work real hard to make panel resonances less excitable.
I estimate that going translam would cost something like 3-5 times more for the box, and bring nothing good to the table. Spend the extra money for a better driver — hard given that the typical best, readily available driver(s) (in a general sense) costs less than the probable difference in box cost going from regular construction to translam.
dave
Fh3 who sells the felt in small qty
First of all I would like to thank Dave, Chris, and all the parties involved in the evolution of this horn. I have been wanting to build a set for close to five years and finally getting around. Funny thing in a downsize I had to let go of my table saw and compound miter. However it has been fun learning to more accurately clean my cuts made with the skill saw by using a router with a strait edge. Then I made my outer panels slightly proud and used a router flush bit. I actually think I am doing a better job now without the table saw/ miter saws. Back to my reason for the post who sells the 1/2 felt?
Thanks everyone on the board for constructive inputs, building things is what keeps me sane.
Bill
First of all I would like to thank Dave, Chris, and all the parties involved in the evolution of this horn. I have been wanting to build a set for close to five years and finally getting around. Funny thing in a downsize I had to let go of my table saw and compound miter. However it has been fun learning to more accurately clean my cuts made with the skill saw by using a router with a strait edge. Then I made my outer panels slightly proud and used a router flush bit. I actually think I am doing a better job now without the table saw/ miter saws. Back to my reason for the post who sells the 1/2 felt?
Thanks everyone on the board for constructive inputs, building things is what keeps me sane.
Bill
Hi Notnick, I am working on producing flatpaks of all three sizes of Frugel-Horns. I've delivered two sets of the XL kits and am currently working on the FH3. Send me a PM if you want further info.
I got the 1/2 felt from McMaster Carr (mcmaster.com) I think it was seven bucks.
Hello again everyone.
Went to check what you guys said about spikes/pads for the speaker. Thinking of buying some spikes just because it looks good, if it sounds better (I don't think I'd notice the difference) thats cool too!
But then I remembered I never showed you my finished product!
So here it is. I feel like the sound improved with the paint, but maybe it is just an illusion. The color looks crazy good in real. Matches my carpet really well.
Went to check what you guys said about spikes/pads for the speaker. Thinking of buying some spikes just because it looks good, if it sounds better (I don't think I'd notice the difference) thats cool too!
But then I remembered I never showed you my finished product!
So here it is. I feel like the sound improved with the paint, but maybe it is just an illusion. The color looks crazy good in real. Matches my carpet really well.
Attachments
Nicely done Fredrik!
Mine were veneered in Cherry and then finished with Rubio MonoCoat.
I cut a set of 3/4" solid Cherry "Outrigger" feet that are shape much like a dogbone.
I used both rubber feet as well as spiked feet on the bottom of the outriggers.
No, I can't say I heard a difference with rubber to spikes.
Mine were veneered in Cherry and then finished with Rubio MonoCoat.
I cut a set of 3/4" solid Cherry "Outrigger" feet that are shape much like a dogbone.
I used both rubber feet as well as spiked feet on the bottom of the outriggers.
No, I can't say I heard a difference with rubber to spikes.
Attachments
My FH3's made the floor vibrate, it is only shuttering ply in the garage, so I bought some spikes on eBay. What a difference it made I'm glad to say everything much clearer.
Cheers
Hey planet10 and others- do you think the Dayton PA130 would be a decent match to this design?
Dayton Audio PA130-8 5" Full Range PA Driver
https://www.parts-express.com/pedocs/specs/295-010-dayton-audio-pa130-8-specifications-46131.pdf
Looks reasonably close to the drivers listed on the plans. I think it would be worth a shot for a budget build, as I'm thinking of doing a set in plywood. Might be a good match with a k-tube super tweeter?
Dayton Audio PA130-8 5" Full Range PA Driver
https://www.parts-express.com/pedocs/specs/295-010-dayton-audio-pa130-8-specifications-46131.pdf
Looks reasonably close to the drivers listed on the plans. I think it would be worth a shot for a budget build, as I'm thinking of doing a set in plywood. Might be a good match with a k-tube super tweeter?
well you could...
Easily build a pair with a supra baffle and try the Daytons. If after living with them for a while you aren't thrilled with the sound you could pop a pair of Alpairs, or Fostex in another supra baffle and give them a shot. I think that this might be the nicest "feature" of the Frugel-horn, aside from the sound that is.
Bob
P.S. I know a guy making kits.....
Easily build a pair with a supra baffle and try the Daytons. If after living with them for a while you aren't thrilled with the sound you could pop a pair of Alpairs, or Fostex in another supra baffle and give them a shot. I think that this might be the nicest "feature" of the Frugel-horn, aside from the sound that is.
Bob
P.S. I know a guy making kits.....
I would spring for a driver that's smoother in the treble region, especially if you're going to use plywood. Just MHO of course.
jeff
Purely in load terms it's fine, decent enough match. I can't comment about the driver's innate qualities, not having any experience with it. No idea about the K-tube I'm afraid; I've never used them, and it would depend on the specific design of the tube and its response with a given tweeter, along with the nature of the crossover.