Cardboard Speakers!

[Sherman]

Yesterday I went to the local Target to try and find one of those $30 digital amps. What I found was a package that contained 2 "portable speakers" and the amp on sale for $24. I didn't care about the speakers but at the price I considered them freebies.

When I got home and opened the package I discovered the "speakers" were actually cardboard cones which were folded flat. They have some type of stick-on motor/transducer/whatever inside.

So I unfold them, they really are just cardboard, and set them up connected to the amp and feed in Ray Charles from the cd player.

I was stunned to say the least! They actually sounded like speakers! I expected them to sound "buzzy" with no high or low end. (Actually I hardly expected a sound from them.) Instead I heard extended lows, decent highs and a fine midrange and no buzzing!

I can't say they are "hifi" exactly. My DIY speakers have "crisper" high-end but these little guys have a deeper bass. I haven't done any FR measurements on them but I might try that next week.

I can say unequivocally that they are the absolute best sounding cardboard speakers I've ever heard!


P.S. That little amp sounds pretty good too!

[jackinnj]

In 1974 when my wife (we were newly weds) and I moved into our first apartment in Brooklyn Heights I bought a pair of Radio Shack full range 8" speakers and fashioned a pair pseudo-horn cabinets out of cardboard -- the results were simply incredible -- I used a Pioneer SX838 which the successive generation of progeny have subsequently used in their college dorms (and now reclaimed by ME!)

After this I used a pair of AR3's, the Dalines (also great speakers), Swans, etc. Now for most of my listening I use biamped Kelidhs, and my favorite B139 reflex design.

[Sherman]

I've fashioned a couple of cabinets from cardboard to try out things before building a real cabinet and sometimes those cardboard boxes can sound amazingly good. But the weird thing about these speakers is that there isn't any "driver" as such. Just that transducer or whatever stuck onto the inside of the cardboard. Imagine a three sided pyramid about 18" tall made of cardboard.

No openings for drivers, no drivers, nothing. Just cardboard.

In the next day or so I hope to be able to find the time to do some FR tests.

[Nelson Pass]

Well, look at this picture someone sent me

[Nelson Pass]

Here's another view:

[jackinnj]

Nelson: wasn't that the horn design used by John Belushi and Dan Ackroyd on the "Blues-Mobile" (a purloined Civil Defense siren) ?

[Kittle]

Done right cardboard enclosures can actually work...

I made one myself just to prove it could ( or could not) be done.

Its not suitable for subwoofer duty ... I got some interesting rattles below 30hz and near silence at 40hz. but above 60hz it works suprisingly quite well.

And with a decent driver, id even have a keeper. The only problem is it tends to be front-heavy and prone to falling over -- the driver weighs as much as the whole cabinet

Now that horn pic has got me pondering about making one of my own.....

[jackinnj]

there was an article in Speaker Builder decades ago "The Folded and Stapled Horn" --

[johnnyx]

Hi sherman

I think those cardboard speakers used NXT technology, "chaotic bending waves" set up in a panel by the "exciter". I have some computer speakers made by TDK which use the same principle. Providing the material has the right stiffness/mass you can use the cheapest one you like. They chose cardboard.

[Sherman]

Originally posted by Nelson Pass
Well, look at this picture someone sent me

Pretty cool cardboard horn! But, I'm guessing that it still has "regular" drivers.

That's the thing that is amazing (at least to me) about these speakers. No "regular" driver. Recognizing that speakers like Magneplanars etc. also don't have what I normally think of as a regular driver this is something different from that.

Still, that photo tempts me to start cutting up some boxes!