Marc1 Proust, 2way 8" waveguide & 5.5"mid, plaster and corks.

[Studio Au]

Ok,

Here begins the new build.

It is a 2 way design, using the Dayton 8" waveguide, combined with currently unknown compression driver. Uk low cost suggestions welcome. Swaying towards using the BMS 4538 goes up to 30khz crosses at 2.2.
http://www.bmsspeakers.com/fileadmin...538_t.data.pdf


The mid I have and so will use is a Peerless M13KH this is a 5.5" driver, very little info is known, i can't find it on the tympany site, and the ebay seller only has this info:
* Rated Power:5/75Watts.
* Resonance Frequency: 45Hz
* Vented Box: 10 -15 L.

Using DCX2496 as the active crossover.

Now my more interesting bit. Looking to cast the baffle as one piece with 5" hole for the mid and the negative of the waveguide, will be 3"ish thick

First Sketchup model, clad in ply:


Xray showing baffle:


Thought about having a curved back, and perhaps bending a sheet of aluminium:


Sketchup Model if anyone wants it:
http://dl.dropbox.com/u/1444609/diya...tudio%20Au.skp

The name, well I have started glueing together lots of corks in slices to build up the curved cabinet. I figure its worth a try, and i will end up with a fairly rigid curved cabinet each cork acting like egg foam. When my computer decides to behave its self, picture below. Oh, and Macel Proudst covered his writing room in corks to not be disturbed.

[Studio Au]

The Corks, Curved acrylic was found in the same shop as the hundreds of corks:







Top and bottom sections have been glued together, thinking of casting the lid in plaster aswell.

The first tests of casting:






So I will create a better cast, as I bodged this one, too much shaking.

Seal the cast, and then box it in, to create the solid baffle.

[keyser]

Very nice indeed! Why are you not crossing a bit lower? I'm sure the off-axis response would benefit.

[Studio Au]

Just running on what the Dayton waveguide specks suggested. Not knowing any proper info about the Peerless mid, leaves me unable to do any modelling, so i guessing my way though. At least the digital crossover allows me to play and tweak the settings, and cross it lower if needed.

The plaster cast looks mildly better in person, it lifted up while casting, hopefully the next will be flush and flawless.

[Studio Au]

Update, have ordered BMS 4538.

The corks are too much work for little reward especially in trying to cast the baffle inside the ribbed walls.

Going to complete one, but for the final pair am thinking of reverting back to the original sketchup pic, wrapped in a nice ply, perhaps with some randomly cut corks for rear wave dispersion.

Without knowing any specs for the driver, does anyone have any recommendations for cabinet size, shape and porting or not. Id rather keep it smaller and so sealed, however at 5.5" might not produce much bass and so ported may be better, but where?

Again it is an unknown, Peerless M13KH Kevlar driver
* Rated Power:5/75Watts.
* Resonance Frequency: 45Hz
* Vented Box: 10 -15 L

Any suggestions warmly welcomed.

[bear]

Oh I see...

Get thee some "sonotube" - the construction paper tube that is used to pour concrete into a hole. Cylindrical. Cut away the section you don't want/need.
Screw the cork glueing.

Alternative is PVC pipe.

There is no real value to wierd shapes for enclosures, except to the extent that the external diffraction can be effected by corners...

Pretty is nice - but doesn't do much for sonics in most cases.

Fwiw, you'll have much better results using the widest baffle you can manage. No matter what.

Casting. Forget "plaster" - the stuff they use for walls in houses.
Find a supplier for ceramics/art stuff - the type of place that sells to artists who mold and cast, and fire stuff in kilns... see what you can find there. <hint>

Also for random drivers, no reason to get nuts on an enclosure design...

Build them up in a standard cheezy wood box, perfect the xover, use the stock plastic waveguide (slather some of that modeling clay on the back to damp it) and see if it sounds worth a damn before killing urself on a fancy box!

Just my suggestion...

Use wall absorption inside the box for best results... not corks.

Maybe make some cork feet for under your gear...?

_-_-bear

[Studio Au]

I got the bag for about 50pence, thought it was worth a try.

The plaster is plaster of paris, for mould making.

I can make the boxes from one piece of sheet ply, and get the wood shop to cut it to size.

I want to try and use the waveguides in another project, if they are ok that it, Casting the entire baffle means i don't have to dig out my router and mess around with cutting circles. Should be pretty inert with 3" of plaster or maybe concrete. Also means I can smooth off the transition from waveguide to baffle.

Cabinet enclosure size? 9/10L sealed?

[bear]

Originally Posted by Studio Au

I got the bag for about 50pence, thought it was worth a try.

The plaster is plaster of paris, for mould making.

I can make the boxes from one piece of sheet ply, and get the wood shop to cut it to size.

I want to try and use the waveguides in another project, if they are ok that it, Casting the entire baffle means i don't have to dig out my router and mess around with cutting circles. Should be pretty inert with 3" of plaster or maybe concrete. Also means I can smooth off the transition from waveguide to baffle.

Cabinet enclosure size? 9/10L sealed?

Right Plaster Of Paris is not the stuff you want.

To know the "right" cabinet size you need to know the T/S params - those you can find online or measure... then plug it into a simple box/speaker response simulator... that will yield a target box size. Then build about 10% larger than the target.

_-_-bear

[Studio Au]

apparently these drivers were test models for the Haybrook H1



: : Heybrook : :

Anyone have any great suggestions for cabinet size/shape?????? Would rather use sealed if possible.

[Studio Au]

HB1 specs:

HB 1 - Specifications:

Sensitivity
90 dB/Watt


Impedance
6 Ohms


Drive units
130mm Kevlar
25mm aluminium

Dimensions (HxWxD) mm
375x210x230


Power Handling
75 Watts


Frequency range
20Hz-22KHz