The P-10 work is coming to an end.
To keep you updated I enclosed some pics. The box on these pics is the sub woofer enclosure.
It is a side mounted ATC 15 inch woofer. Box is sealed with approx. 80 liters of volume. Q near 0,75.
I am using here an idea derived from my P-2. It is what I call a radial matrix bracing system. (RMBS)
It is a very effective and radical way of stiffening
the box. In fact it is so stiff, it is indistinguishable from a solid
wood block. (I mean the knocking test) Unbelievably stiff. It helps the
sound to be very well controlled and free of room positioning. "Dirt"
radiating from vibrating boxes causes the speaker to disappear less effectively.
If we hear no dirt just signal, the sonic picture is very real, free
of box image.
So I use eight partition boards connecting directly the driver
basket screws to the rear wall and side walls.
The sub woofer box seen from behind. Rectangular
hole in the back is the terminal plate opening.
This driver is placed actually on the opposite
side of the box, just to show better the idea behind the radial bracing.
Screws will be driven directly into the bracing boards.
The whole box is made from 25 mm MDF (1 inch).
The sub woofer box lying on its front side. Terminals
in place. XO is in a separate sealed cavity.
This is the sub woofer attached to the dipole
board - 40 mm solid wood.
The woofer will be mounted ON TOP of the plywood cheek, which is
i inch thick. (poetry?)
The side walls will be attached to all that (decorative cheeks)
- 1 inch MDF and the driver openings will be larger than the basket, forming
a natural recess.
The speaker from behind (actually the box stands
wrongly the front side to the back, I am sorry).
This is the termional plate covering the chamber for XO components.
Ready XO elements.
Everything except drivers is ready
Drivers waiting for installation.
Decorative side panels are being glued. The lines are "fake joints"
made with a table saw, to make the side look a little lighter.
Now that's how it will look:
I have spent 4 nights re-working the XO in the P-10.
It does not play the best without quite complicated XO.
Finally, I was very very happy with the precise measurements. I reached the limit of resolution of my measurement equipment and room interaction.
So IN MY ROOM and with MY AMPS and everything else, this new XO measures very well, ± 1,5 dB flat.
So how did it sound on music?
In one word - very good. Very good. Everything that I loved about P-10 is still there, but the Raven problems disappeared completely. Now, with 3-rd order filter the ribbon started to sing. It has body and zzipp and zzinggg and it is a hellofatweeter. Now, I must admit, it is a whole step above any tweeter dome. And it integrates well with ATC mid dome.
The whole presentation is VERY right. It just sounds right and true. I absolutely cant name one thing that I am not happy about.
I am quite sure, that this sound beats by a wide margin anything I heard from Scanspeak/Dynaudio/Seas kind of speakers.
NOW with this very hard to make crossover I can recommend this project without any hesitation to anybody shopping for 20-40 thousand dollar speakers.
Crossovers ready to be mounted.
OTHER ATC SCHEMATICS I HAVE FOUND
and this is the one from Italy from Proac speakers:
