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!
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!
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.
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.
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.
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.
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.....
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.....
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.
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.
Nelson Pass said: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!
johnnyx said: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.
You are right. I've been looking at the "documentation" with the speakers and amp and it is NXT technology. I have a set of flat panel computer speakers (or I did before my son took them to college) based on NXT technology also. But I didn't expect it to work with plain old cardboard! I assumed the panels were specially designed and were more like ribbon speakers.
I went back to the store today thinking I'd pick up another set but they were gone. The guy there said they also had just the "exciters" that you could stick on anything like photographs or posters to turn that thing into a speaker. Of course they were out of those as well. He said they were $10. I'm going to keep looking for that.
I saw these from Sonic Impact on Target's website:
http://www.target.com/gp/detail.html/ref=br_1_20/602-7280254-4702241?_encoding=UTF8&asin=B0001HKVKQ
I would be fun to see what they can really do.
http://www.target.com/gp/detail.html/ref=br_1_20/602-7280254-4702241?_encoding=UTF8&asin=B0001HKVKQ
I would be fun to see what they can really do.
Attachments
DC Dave said:
Dave,
Those are the do-hickeys (technical description) that they had in the store and the same things that are stuck on the cardboard speakers I have. I'm going to a client's office in a few minutes and will drive right by a Target store. I'm going to stop in and see if they have any left.
I did attempt to measure FR of the cardboard speakers this morning but couldn't. When playing a 1K Hz tone and setting the volume to 0 db on my meter I encountered a problem. At about minus 2 dB the speakers began emitting a second, completely different tone simultaneous with the 1K Hz signal.
I think it was harmonic resonance and it might be curable by just lifting the speakers a bit but I didn't have time to check it out. Maybe tonight or tomorrow.
I stopped at another Target store today and found three more sets (amp, speakers, carrying case) on sale for $12.54!!! Half the price I paid a couple days ago. (BTW these Target stores are in the far west suburbs of Chicago.)
Of course I bought one. I'm planning to mod the amp, new case, RCA inputs, binding post outputs etc.
I also managed to get by American Science and Surplus and picked up two 12VDC 1A transformers for $3.95 each. I have the original amp and speakers playing right now on one of these transformers and it seems to be working fine so the power supply seems taken care of.
I'll probably take the exciters out of one set of speakers and try them on different materials.
Fun stuff for cheap.
Of course I bought one. I'm planning to mod the amp, new case, RCA inputs, binding post outputs etc.
I also managed to get by American Science and Surplus and picked up two 12VDC 1A transformers for $3.95 each. I have the original amp and speakers playing right now on one of these transformers and it seems to be working fine so the power supply seems taken care of.
I'll probably take the exciters out of one set of speakers and try them on different materials.
Fun stuff for cheap.
Hi Guys,
speaker cones are made of paper, so why not boxes?
more cardboard speakers at http://au.geocities.com/footstony
regards Philip
speaker cones are made of paper, so why not boxes?
more cardboard speakers at http://au.geocities.com/footstony
regards Philip
For some information on bodging your own, have a look at:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10608&highlight=
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10608&highlight=
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.