My sound system was broken so I decided to make a simple amplifier circuit with vu meter. It works pretty good and it's cheap too. I got my parts about 16$. So start to make your own mini Sound Riser I promise that it will worth it if you done everything correctly.
Step 1: Collecting Required Parts and Schematic
-150W / 4Ohm / Dual Cone LoudSpeaker
-VUMeter and Amplifier circuit (Kit or do it yourself)
-12V and 9V battery
-FM Transmitter Circuit
-FM Receiver Circuit
-9V Battery Clip
Step 2: Start Making...
First, we need to put our loudspeaker into the enclosure. I use some hot glue to hold it in place.Then, I connect 4 wires (2 per each terminal of the speaker). 2 of them goes to vu meter circuit and others are go to the amplifier circuit. At this point I drill some holes in enclosure and hot glue the vu meter.
Step 3: Making "Audio In" Jack
I cut out two piece of long wire and solder it to the jack and secure everything with heat shrink tubing.
Step 4: Building the Receiver
I made a FM receiver circuit and solder "output" wires to the "input" of the preamplifier according to the schematic.
Step 5: Transmitter Circuit
Now, we need to make the transmitter circuit to transmit our voice to amplifier. For this I used radio transmitter and some other components.Then I tune it in the non-used radio frequency and test it luckily it works.
Step 6: Assemble Everything Together
It's time to assemble everything according to the schematic. I put amplifier and preamplifier in top enclosure and make a groove to feed wires inside of it. Then add some final touches and hot glue everything in the big speaker enclosure.
Step 7: Results...
In conclusion; I think that it have pretty good sounds and style. However It also needs a paint job and some minor adjustments. There is the video I hope you liked it.
P.S.= Sorry for bad english and video. Wireless voice transmission not shown in video.