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Ask Slashdot: Cheap and Fun Audio Hacks?
An anonymous reader writes: A few years back I discovered that even a person of limited soldering skills can create a nifty surround-sound system with the magic of a passive matrix decoder system; the results pleased me and continue to, It's certainly not a big and fancy surround system, but I recommend it highly as a project with a high ratio of satisfaction to effort. (Here's one of the many, many tutorials out there on doing it yourself; it's not the long-forgotten one I actually used, but I like this one better.) I like listening to recorded music sometimes just to hear how a particular playback system sounds, not just to hear the music "as intended." I'd like to find some more audio hacks and tricks like this that are cheap, easy, and fun. Bonus points if they can be done with the assistance of a couple of smart children, without boring them too much. I have access to Goodwill and other thrift stores that are usually overflowing with cheap-and-cheerful gear, to match my toy budget. What mods or fixes would be fun to implement? Are there brands or models of turntable I should look for as the easiest with which to tinker? Are there cool easy-entry projects akin to that surround sound system that I could use to improve my radio reception? I'm not sure what's out there, but I'd like to get some cool use out of the closet-and-a-half I've got filled with speakers and other gear that I can't quite bear to toss, since "it still works."
It's fairly common, but you didn't mention it, so a simple circuit hooked up to christmas lights can be fun.
"First they came for the slanderers and i said nothing."
One of the coolest hacks I have encountered is the use of a computer sound card's audio input(s) to create an oscilloscope.
Google provides lots of links on the subject.
If it weren't for deadlines, nothing would be late.
It's like Dolby surround. Information for the additional channels is encoded into the original 2 channels.
You won't get 4 independent channels though, but I think it still counts as an analog decoder.
More info: https://en.wikipedia.org/wiki/...
Try a singing Tesla coil. Kids will love making music with lightning.
Actually, from an audio engineering perspective, this is quite true (at least for vinyl), since all records were run through a low cut filter in order to eliminate rumble/skipping due to low sonic frequencies distrubing the needle in a record groove.
If we are talking a clean, complete signal, vinyl records have plenty of deficiencies of their own, despire what so-called "audiophiles" might tell you.
The O2 headphone amplifier is an extremely clean amp that can drive almost any headphones. It sounds great. Pair it with a clean DAC, rip all your CDs to FLAC, and you can listen to your music from your computer with the very highest in fidelity.
If you can solder, you can build the O2 amp for $30 to $40 worth of parts.
http://nwavguy.blogspot.com/2011/08/o2-summary.html
The guy who designed the O2 also designed a really good DAC. He wanted to release it as a DIY project but the realities of the DAC chip business mean that it was only practical to sell a complete DAC board. But you could make a project out of building an O2 amp in an enclosure with the DAC board built-in. (I have such a device but I can't solder; I bought mine from JDS Labs, pre-built.)
http://nwavguy.blogspot.com/2012/04/odac-released.html
I am friends with a world-class audio expert, and he agrees that the O2+ODAC is the best way to spend your money. It's as clean as $1000+ solutions.
P.S. Article about the guy who designed the O2 and ODAC: "the audio genius who vanished"
http://spectrum.ieee.org/geek-life/profiles/nwavguy-the-audio-genius-who-vanished
lf(1): it's like ls(1) but sorts filenames by extension, tersely
...but, back in high school, one of my science teachers glued a tiny mirror to the center of a speaker cone. He then reflected a laser off of it onto the wall. When he played music though it, the vibrations made a very cool low cost laser show! Now that lasers are cheap and plentiful, I've always meant to recreate that laser show. One of these decades, I'll get around to it! ;-)
Dynamic range compression is one of the audio effects I use most often.
Glue a Front Surface mirror to a woofer
Point a Laser at the mirror
Play music with lots of bass through that speaker
Add a second speaker at an opposing angle to get X Y control
We are Dead Stars looking back Up at the Sky
Plus you get to tell them, nobody touches my theremin!
You don't seem to understand the terms decode and encode. They are not unique and new to the digital realm. Audio / Analog encoders and decoders existed before computers. I assure you, this circuit functions as a simple analog decoder.
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
Yes, they do. They work perfectly well. You can't hear them, but they work just fine.
Is it just my observation, or are there way too many stupid people in the world?
> Actually, from an audio engineering perspective, this is quite true (at least for vinyl), since all records were run through a low cut filter in order to eliminate rumble/skipping due to low sonic frequencies distrubing the needle in a record groove.
sub 20 hz would be filtered by the rest of the audio chain (hello psychoacoustic filter on all compressed music), or would end up disturbing the mix anyway. Judging the excursion of the speakers in some badly mastered techno records, i think that vinyl can go sub-20hz.
The problem with skipping is instead the low frequency phase, due to the way stereo information is encoded in the groove.
> If we are talking a clean, complete signal, vinyl records have plenty of deficiencies of their own, despire what so-called "audiophiles" might tell you.
Well I'd first scrap 44.1khz, cellphones, pc speakers, crappy DACs, only then I'd look at vinyl.
The low range is good enough on vinyl, it's the upper range that suffers, plus those pops and noise.
OTOH the sound of vinyl is not a clean signal + the noise of the needle on the groove, it's obvious that picking up the signal distorts it more than a DAC does, whether that ends up in a pleasant effect, not unlike valves, it's debatable. Personally I listen to the music, not the system.
---- MISSING MISCELLANEOUS DATA SEGMENT --- [sigdash] trolololol
My suggestion is not super cheap at $589 yet very satisfying: an Elekit tube amplifier kit. Elekit is a good japanese kit brand and their tube amp kits are very well regarded. In fact a similar quality ready made product would cost a lot more.
Here is the link to the importer in Canada who delivers to the Americas. He supplies the construction manual in English, this is I think not the case if you buy straight from the japanese Elekit website: http://www.vkmusic.ca/TU-879S....
I've got a friend who's a cabinet maker and loudspeaker designer. For years he crafted full-range curved diaphram electrostatic loudspeakers. Nowadays he's into horns. One day I dropped by his shop and he blew me away with something he'd been doing with Dayton Audio Sound Exciters (well, that's what they're called today on Amazon's web site). They're transducers.
Get yourself two 2' x 3' pieces of 1/2" thick piece of foam core from an art supply store. Attach two of these Dayton Audio Sound Exciters to each of them. Wire them in parallel and connect them to an amplifier. The tricky part is that you have to suspend them in mid-air. Hang them from your ceiling or something. The sound you'll get out of them is very, very good - especially considering you'll have less than $75 in the whole project. I'd put it equal stuff you'd spend about $1000 to $1500 at Best Buy.
They aren't what I'd call extreme hi-end, but they sound much, much better than anyone would think. Would make for a great garage or shop system.
you can use a flame as a speaker. Cool thing is you can't burn it out by overdriving it!
1) create a large wide flame. e.g. for gas flatten a tube into a long thin jet.
2) put two electrodes in the flame
3) boost your audio into the high voltage range. a high voltage transformer can do this.
Now say "I am the great and powerful oz!" into the microphone.
4) get really excited and build a redonkulously large version with 6 foot tall pulsating glames and a a kilowatt amplifier.
Some drink at the fountain of knowledge. Others just gargle.