Discussion on what materials to build speakers out of

[gpapag]

Originally Posted by planet10

Shoog is particularily enamoured of that isophon. All the ones i've seen (and have) have been in the co-axial form.

dave

Hi Dave
Mine are not coaxial (they used to be fitted in a Blaupunkt radio/turntable console from the 60s)

[gpapag]

Those baffles should have interesting performance.

They are much more neutral (acoustically) than the pine wood panels (boomy!), but they do not achieve to (acoustically) disappear as much as the panels made out of roll package paper

[tiefbassuebertr]

Originally Posted by gpapag

OB panels made out of two 8mm thick plywood panels, spaced 8mm apart with flanges made out of cork, glued with white PVA to the plywood. Empty cavity filled with dry sand.

Regards
George

Great work. This kind of insulation I like. But there is a much more easy way to realize this.
Therefore you need also two 8mm thick plywood panels
The first step is gluing a frame along the outer edges of one plywood panel and some four square cuts in the same thick than the woods for the frame.
The next step is filling dry sand with a grain size of about 0.2-0.5 mm possibly mixed with lead shot. Please note, a bit more than the chamber size.
Now the second plywood panel closes (about gluing) the chamber with the dry sand where the sand is pressed a bit (third step).
The last step is the exact cut into the framing (of course, after the curing of the adhesive).
In this kind you can also create the the footprint parts in a hifi rack for the audio components.
My english is not so good, thus not all details I can explain in great detail - but I hope, the basic principle is to understand.

Now an off topic question: I need a little help by try to contact to a guy from your country.
At a forum are discussed any repair problems by the DVB-S reveiver "500" from Dream Multimedia (Dreambox). Here is the link:
http://www.sdtv.gr/smf/index.php?topic=18935.0
If you scroll down you will find a small schematic sample from the member "dimitris_p" arround the faulty MOSFET part.
This means, this member must have the complete schematic of this dreambox version.
Perhaps you can contact this member and ask, wheter he can send the schematic to you (if is not too much trouble for you).
And then you can send me this schematic to my address (not the PM aera here):
kirschner-hifi@tiefbasswiedergabe.de
Thank you very much

[Beos]

Looking around for sound dampening materials i came across this type of multiplex, not my thing as its very expensive but maybe useful for others.



Merfoflex geluidsdempende sanwichplaat met twee lagen multiplex

It’s used to isolate boats, trains etc and is available in 2 thicknesses.

Haven’t seen it before and didn’t read about it over here. If known, well, the better!

[tiefbassuebertr]

Originally Posted by Beos

Looking around for sound dampening materials i came across this type of multiplex, not my thing as its very expensive but maybe useful for others.
Merfoflex geluidsdempende sanwichplaat met twee lagen multiplex

It’s used to isolate boats, trains etc and is available in 2 thicknesses.
Haven’t seen it before and didn’t read about it over here. If known, well, the better!

check out this (from the German speaker builder magazine "Hobby Hifi")
Die Tricks der Profis
dämmung-und-versteifen
was-tun-gegen
HAUPT