Foam Core Board Speaker Enclosures?

[xrk971]

Originally Posted by cochleus

For a couple of years I was trying some kind of different idea/prototype about every two weeks or so. I still have a closet stacked full of experimental speaker enclosures collecting dust. It was great fun and I learned something. Now I like the sound of open baffle until I find something even better.

Ahh... OB is the Zen way.... I have an old oak tabletop sitting in my garage left there by previous Occupant that would make a great OB. The huge crossovers ($$$ coils) required are holding me back. I think you are better off with a two cheap T amps but how do you implement the crossover at line level before T amps? There are some fairly low cost woofers out there to go with the Viva TC9FD. Can OB be done for under $100? $24 for drivers, $30 for woofers, $40 for 2 T amps, just need cheap line level crossover. The thread on cheap OB was priced at $400 - hardly a cheap experiment, although they will sound fantastic.

[cochleus]

Originally Posted by xrk971

Ahh... OB is the Zen way....

Yeah, in fact I have a Zen amp driving my OB.

I just am starting the work of understanding how to bi-amp using something like the First Watt B5. I would like to build the circuit myself using 2sk170 jfets.

My first OB was foam core

[xrk971]

Originally Posted by cochleus

Yeah, in fact I have a Zen amp driving my OB.

I just am starting the work of understanding how to bi-amp using something like the First Watt B5. I would like to build the circuit myself using 2sk170 jfets.

My first OB was foam core

How does OB sound with foam core? I just went to dollar store and got 10 more sheets of foam core. Why can't we use cheap car audio active crossover and bi-amp rather than spending a fortune on big heavy coils and power resistors (heaters really)? I think an OB can be done for cheap as follows:
2 Viva TC9FDs $24, 2 GRS 12PF -8 12 inch woofers $32, Boss BX25 2 way active x-over $33, 2 Lepai amps $40, about $130 total not including s/h and wood or foam core boards .

[cochleus]

I've heard that bi-amping is the way to go with OB. I tend to being a full ranger myself, but bi-amping a woofer interests me. I have parts for another class a zen for bi-amping, but I'm building one with my nephew first. I really like the way bass sounds on an OB. The beauty of foam core for me was being able to sculpt anything I could imagine quickly and on the cheap. If you like it then you can make it out of whatever you want, or can afford.

[cochleus]

Originally Posted by VaNarn

An interesting material called XBOARD PLUS PANELS

Looks like an interesting material to try for a baffle, plus I like that it's "green".

[Cal Weldon]

Originally Posted by xrk971

How does OB sound with foam core?

I am not familiar with the term 'foam core'. Can you give me a link? I am familiar with many of the products that meet that description and they vary a lot.

Thank you.

[sandyhooker]

Originally Posted by cochleus

Yeah, in fact I have a Zen amp driving my OB.

I just am starting the work of understanding how to bi-amp using something like the First Watt B5. I would like to build the circuit myself using 2sk170 jfets.

My first OB was foam core

Which Zen are you using??? Most are only 10-20 watts.

[xrk971]

Originally Posted by Cal Weldon

I am not familiar with the term 'foam core'. Can you give me a link? I am familiar with many of the products that meet that description and they vary a lot.

Thank you.

The Elmer's brand shown here is really nice stuff but expensive $69 for 25 sheets, I use the stuff from Dollar Tree store ($1 a sheet, I guess that's obvious). Basically it is very light but stiff paper faced polystyrene foam. It cuts with an xacto, and is easy to glue with craft white glue or hot melt if you are in a hurry. Give it a try and you will be amazed at how light weight speaker cabinets can weigh and still sound good. If you have kids they love to decorate the cabinets with markers or paint.

The Elmer's brand is here: Amazon.com: Elmer's 900109 Foam Board, White Surface with White Core, 20 x30, 25 Boards/Carton: Office Products

The Dollar Tree stuff is here:Bulk Readi-Board Foam Boards at DollarTree.com

[cochleus]

Originally Posted by sandyhooker

Which Zen are you using???

Mine is only 5 watts per channel, it is a First Watt F2J clone that I built myself.

[VaNarn]

The X BOARD PLUS PANELS are available in the 'States from http://purepanel.net/images/Purepanel_Plus.pdf I would not advocate the use of lighter weight materials on basic O.B. speakers as mass and stays are needed to overcome inertial forces created by the reactive forces.