[Bogdan] received this set of Serioux Panda speakers as a gift. I turns out that they sound very good and he decided to make them more useful to him by converting them to work as Bluetooth speakers.
To begin with he bought the cheapest A2DP device he could find. This is the protocol that identifies a Bluetooth audio device. The unit is designed to provide a Bluetooth connection for a set of headphones. He patched into the headphone port on that board, but also wanted to keep the option of using the Panda speakers’ line-in. To do this he added a 1k resistor to each of the audio channels. A connection was made from the 5V rail of the speakers to power the Bluetooth module rather than leaving it with its own battery.
Speaking of batteries, the Panda speakers can run from three AAA cells. This battery compartment was a perfect place to mount the add-on hardware. But the speaker can still be powered from a USB connector. Above [Bogdan] is using a portable USB power supply.
[Michael] wanted a stereo that he could use outside, be it at the beach, beside the pool, or while tailgating. He decided to build this boom box himself, and didn’t cut any corners when it came to a professional looking finish.
Because of the locale in which he plans to use the stereo he went with a set of marine speakers. They’ll have no problem standing up to water, and since they’re used in boats they should also be able to take a beating during transport. To feed it he uses a Lepai T amp which is seen above.
After cutting each piece of the case out of MDF he started working on the openings to receive the components. This involved quite a number of layout lines and some work with a compass to map out the circular openings. He built a recessed panel on the back to interface the power cord for charging. Inside is an 18 Ah battery. A set of switches lets him turn on the charger and choose between powering the amp from battery or from the power cord.
Here are two different briefcase speaker projects. [Dale] built the offering on the right back in high school and the upgraded version 2.0 more recently. He was inspired to send in a tip for the projects after seeing yesterday’s suitcase full of tunes.
The first version uses a pair of speakers pulled out of a car at the junkyard. They’re mounted on some particle board which beefs up the side of the plastic briefcase. The amplifier that drives it is mounted inside the case along with a battery to power the system. [Dale] included a crude storage bracket for the input cable and since the amp can drive four speakers there are connectors on the outside for two more.
Version two has quite a bit more polish. He doesn’t show that one off quite as much, but you can see there is a LED strip on the case that serves as a VU meter, as well as a numeric display which might be battery voltage? He mentions that this blows away any commercially available systems his coworkers have brought to the job site.
Video of both rigs can be found after the break.
Continue reading “A pair of briefcase boombox builds”
[Texane] picked up a 2.4 GHz transmitter/receiver pair for transmitting sensor data wirelessly. After using them in a project he wanted to try pushing them a bit to see what the limits are when it comes to higher bandwidths. He ended up building a wireless speaker that transmits audio at about 90 KB/s. That link leads to a subfolder of his git repository. The code for this project is in the RX and TX folders, with images and video in the DOC folder.
The radio hardware that he’s using is a Nordic nRF24L01P chip which is available on a breakout board from Sparkfun. [Texane] mentioned to us that the chip includes error checking, packet ACK, and automatic retransmission. But these add overhead that can slow things down. The chip does offer the option to disable these features to get lower level access to the hardware. That’s exactly what he did and he mentions that the example code he wrote for the transmitter and receiver make every cycle count. This makes us wonder if it’s the speed of the ATmega328 chip that is the bottleneck, or the transceivers themselves?
Take the party with you by building your own boomcase. It’s an amplifier and set of speakers built into luggage. It uses an audio jack to connect to your favorite music player, and with a bit of added protection — like grills for those speakers — it could still be gently used to transport your wardrobe.
A 1960’s suitcase was mutilated for this build. [Jay] must have already had it on hand because combined with some used parts he claims to have only spent $50 total. After trying out a few different speaker orientations on a piece of cardboard he covered the outside of the case in blue painter’s tape and started cutting holes. The amp he chose has a nice face plate which happens to fit nicely on the top side of the case. For now he’s powering it with a 10,000 mAh (ie: 10 Ah) portable device recharging battery. But as you can hear in the demo after the break this seems to have no problem supplying the system with enough power.
Continue reading “A suitcase full of tunes”
This is a great project for a slow afternoon, or a beginners introduction to DIY. [William] shows off a really simple speaker project that results in a light show as well as a decent enclosure. He’s using a PVC elbow to mount the speakers. They’re just glued in place. Below that, a section of clear tube allows for the lighting effects and a flange at the bottom supplies stability. For the lights, [William] opted to forego any complicated electronics and simply wired LEDs to the speakers themselves.
Admittedly we’ve seen more complicated systems in the past, but his results are quite nice and could be done pretty fast.
Back in the 1980’s there was a movie cliché that the person with the largest boombox on their shoulder was always the coolest. It’s obvious to us that [Tim Gremalm] thinks that’s silly. Why be uncomfortable carrying something like that on your shoulder when you can strap a much larger object to your back? He’s working on a mammoth speaker enclosure which can be carried around, but he needed a set of backpack straps to make it happen.
This thing is going to be adding some serious weight to his body, so he also whipped up the padded waist belt seen above. For fabric he reused an Ikea couch cover. The material is made to survive a lot of pulling and stretching. For padding he used what he calls ‘floor mop’. It looks like it might be microfiber mop cloth be we can’t really be sure. With ten layers of the mop encased in the couch cover he finish off each strap by sewing it to some nylon webbing.
After the break you can see a picture of [Tim] modelling the huge polycarbonate speaker enclosure for which these backpack and waist straps were made. This project has many posts associated with it so if you’re interested in seeing more you can use this project tag link.
Continue reading “Fabricating your own backpack straps for unorthodox uses”