Frugel-Horn Mk3 Builds & Build Questions

Drone 7 ... Should have been more specific. No accessible AC that I can use use for tools other than apartment. Running a router, etc inside apartment is same as doing inside a house. I would get stoned.
Zene
Just a late thought ... Understand big ugly router is a no-go ... I was unclear on the jig-saw (price and blade wander were mentioned).

What about a Dremel?
Mounted on a stick of appropriate radius with a <=1/8" bit, two quick shallow swipes to frame/guide the cut on either side, then cut through with a coping saw and plane/sand at your leisure.

If the source of stoning is inside the apartment, engrave something nice first. If outside, answer the door with a hair dryer in your hand.
 
Hi, I've just built a pair of almost finished Mk3 Frugel Horns. I say 'almost finished' because the speaker box isn't glued, but screwed together so that I can still make adjustments. The woofers are Alpair-7MS. The cabinets are made from 18mm plywood, and I plan to veneer them with walnut wood.

I'm pleasantly surprised by how good these speakers sound. I compare them with Monitor Audio Silver studio monitors and feel that the Mk3s only lag behind in the higher tones.

But what I would like to ask is this: are there any tips for experimenting with the damping to achieve different sound variations? Currently, I've stuffed the back side with 35g of acoustic stuffing (in the point) and placed a 35g loose fluff ball in the front compartment. I could leave it as is, but I'm thinking about experimenting with less damping material.

Thanks, Bart.
 
I built my Mk3's for the Fostex FE126en and used the appropriate damping guide. Years later I swapped the Fostex's for the Mark Audio drivers but didn't change the original damping. The sound is so good I could not be happier.


P1010015 4.jpeg
 
So I tested the speakers with different amounts of dampening material. I must say that the difference in sound is certainly there, but it is minimal. And I also prefer the speaker with less dampening material. I've even tried without any dampening wool (front and back campartiments empty, normally around 2x 35g wool), but always with the felt glued to the inside of the top (around the position of the woofer).
 
Looking at the drawing it is needed a "wooden L" with the "vertical" part long around 143 mm and with the same angle of the rear side of the FHXL.
It will have the function of the reflex pipe if I understand correctly, so it will change the principle on which the FHXL work.