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Any updates on near-field use? I was thinking of a small pair for a very small office where listener is only 4' away sitting at a work bench.
I made a 14in pair and used with 2in drivers for my office and they worked well at 4ft away. Not much bass below 100hz but that was fine for the office.
xrk971, how do you do straight cuts with xps foam? I'm thinking about making some kind of alignment tool for knife blade as xps is much thicker than foam core.
It turns out that xps is dirt cheap compared to hobby store foam core and as an added bonus it's just slightly thicker than mdf/bb, so the prototype size can be nearly the same as final speakers.
It turns out that xps is dirt cheap compared to hobby store foam core and as an added bonus it's just slightly thicker than mdf/bb, so the prototype size can be nearly the same as final speakers.
Use a new break-away blade utility knife with a deep enough blade that can cut through. I buy mine in 3 pack from dollar store.
Put XPS on carpet floor, use a long piece of hard material like Masonite for a straightedge. It should be wide enough so you can use your hand to easily apply pressure to secure it and keep from wiggling during cut. A skinny metal ruler is not as good as it has too little contact area to hold steady.
Start cutting using straight edge as guide and keep blade vertical. Do 4 to 5 cuts each time deeper. Do not try to do in 1 or 2 strokes. A sharp blade is essential for clean edge.
Why on carpet? It protects blade and gives room to cut through and allows your body to be positioned above work piece to ensure straight vertical down cut angle.
Put XPS on carpet floor, use a long piece of hard material like Masonite for a straightedge. It should be wide enough so you can use your hand to easily apply pressure to secure it and keep from wiggling during cut. A skinny metal ruler is not as good as it has too little contact area to hold steady.
Start cutting using straight edge as guide and keep blade vertical. Do 4 to 5 cuts each time deeper. Do not try to do in 1 or 2 strokes. A sharp blade is essential for clean edge.
Why on carpet? It protects blade and gives room to cut through and allows your body to be positioned above work piece to ensure straight vertical down cut angle.
The Alpair 12p has some known frequency response anomalies compared to it's factory published curve. However, perhaps in a similar way to the CHN-70, placing it behind a K-aperture in a Karlsonator will cure the issue? In any event a Karlsonator is excellent for deep rich full bass without baffle step loss.
Here is a sim I did of Alpair 12p some time ago:
http://www.diyaudio.com/forums/full...sonator-0-53x-dual-tc9fds-80.html#post3956297
This is a Karlsonator 8 (or 8/12 scale Karlsonator).
I searched for cardboard boxes after building quick sealed enclosures (I first did that as a kid, now I'm surprised they sound good) for my new cheap chinese 5" 60w 4ohm speakers (Silverton TS-1300, couldn't find their T/S params :/ ), and stumbled on this thread, diyAudio never disappoints me.
As far as I read, I'll only scale the Cornu design to fit my speakers. I only found 17mm thick popcorn foam (popcorn = expanded polystyrene which is EPS not XPS, XPS is extruded polystyrene ).
The plan is to lay the spiral with cardboard (since it's flexible), and the sides with the thick EPS. Are there other forgiving designs like Cornu or just build a sealed big tower and call it a day (I'm considering the BIB, but that needs some T/S params if I recall) I might do T/S measurements for my speakers at a later time.
As far as I read, I'll only scale the Cornu design to fit my speakers. I only found 17mm thick popcorn foam (popcorn = expanded polystyrene which is EPS not XPS, XPS is extruded polystyrene ).
The plan is to lay the spiral with cardboard (since it's flexible), and the sides with the thick EPS. Are there other forgiving designs like Cornu or just build a sealed big tower and call it a day (I'm considering the BIB, but that needs some T/S params if I recall) I might do T/S measurements for my speakers at a later time.
Years ago, I built a pair of speaker enclosures using 1-inch thick Styrofoam panels and Elmer's white glue. The drivers were 8-inch Polyplanars (also Styrofoam) so there was a certain logic to the combination. The glue worked great - best joints among panels I have ever attained - but, not surprisingly, the panels exhibited far too much resonance and muddled the sound. It was a quick and easy project, though.