This system was started off cobbling together assorted spare parts that were in the garage gathering dust, to create a small battery powered (and partially solar) system that can fit in the boot of the car and be moved on a small trolley. But of course then I added some extra bits as well to get it how I liked it, so it’s not really assembled from “junk” any more, but it is all inexpensive low power use.
The components are:
Pioneer TS-W254C car subwoofer. 500Wmax/250W nominal. 10″ driver 4 ohm. This is in an MDF box, the pioneer was added later and doesn’t match the enclosure. I have discarded the busted plate amp and made 2 small bass reflex ports from PVC tubing which has given it a bit more bass.
Pioneer 6×9 “4 way” car speakers Pioneer TS-A6980S purchased second hand from ebay, mounted in some 6×9 speaker boxes, also purchased from ebay. These have OK response above 200hz, but quite terrible bass. But that’s ok combined with the subwoofer. The speaker boxes sit on some $4.50 plastic stools that make quite fine speaker stands.
The “official” specs are:
- 1-1/2″ PET silver film cone tweeter
- 3/4″ PET silver film dome supertweeter
- 2-5/8″ PPC balanced dome midrange
- Aramid fiber reinforced IMPP woofer with durable rubber surround
- frequency response 25-30,000 Hz
- recommended power range 2-80 watts RMS
- peak power handling 350 watts
- sensitivity 93 dB
Above: Smoothed graph taken indoors approx 1.5M from one of the satellites, one satellite + subwoofer only. This is with sub polarity reversed (there is a bit of a dip otherwise) and the sub cutoff control on the amp at max. The 60hz bump is a room effect I’m fairly sure, so without needing too much tuning these drivers and the amplifier match fairly well.
Class D TDA-3116 2.1 amp “100W” sub channel and 50W per side stereo. Fairly crude control of the bass cutoff freqency, but it turns out it works quite well with the drivers I have (see the above graph)
Ebay 12VDC 120W “laptop” power converter – this can run from 240VAC mains or 12VDC – using this to feed the TPA3116 amp 24VDC which gives it the best output. As I’m using 2 x 12VDC 7AH batteries I could also rig these in series to get 24VDC, but right now I’m using the voltager converter and can use 1 more 12VDC batteries.
very simple. entry level 5W solar cell with a very basic charger on it. At medium volumes the system uses about 10-15W or more so this just helps stretch out the battery life on a sunny day, and is used to charge the batteries when the system isn’t in use.
iRig mix USB powered mini mixer.. despite the “i” branding there is nothing particularly apple specific, its just a minimal, but adequate DJ mixer that can be powered from a 5V USB power supply. The 120W power adapter also has a USB power out that can power this, but I also have a small USB power pack phone charger that can charge this as well.
I originally had a small DIY mixer made from a CMOY heapdphone amp kit but the lack of EQ and cue function annoying.
Mainly a Samsung android tablet running the quite excellent Mixvibes Cross DJ app, also CD walkmans or whatever else is about.