Gear from the "Linux Sound Shoot Out" - a blug.org meeting on 3/2/2006
- Center top: Keiga 2.1 plate amp (black amp in back with heat sinks)
- Center top: T-Amp (small silver arch in front of black amp)
- Center bottom: 8in subwoofer in a ported box
- Out-1: small tube speakers
- Out-2: 3 inch "full range" speakers
- Out-3: Altec MX-5020 computer speakers from a local store
- Not shown: Klipsch ProMedia Ultra 2.0
- Not shown: iRiver and Samsung mp3/ogg players
Keiga 2.1 plate amp - $136
Specs: 2x25W stereo for satellite speakers, 50W mono for a subwoofer, adjustable 12db/oct
electronic crossover, RCA and mini jack input connectors. We used this to drive the home
built speakers and blew away the commercial computer speakers. Not a surprise with more
power and bigger drivers. The music was provided by mp3/ogg players which were fed directly
into the mini jack input.
T-Amp
- $30
A digital amp rated at 15w/channel max into 4 ohms, about 10w/channel at low distortion.
It runs on 8 AA batteries or an external transformer (optional) that provides 12V DC
at 1.5-2.0 A. We used a transformer. It will drive the 3 inch speakers to a moderate
level on a desktop and the 2-way tubes loud enough to function as a small stereo. In
either case you will probably want to boost the bass but the T-Amp does not have tone
controls. The EQ on my mp3/ogg player works well but those on my Linux desktop players
are not adequate. Adding a powered subwoofer will make a big difference.
8 inch subwoofer
This uses a Dayton
Quatro 8 in a 0.85 cu-ft box with a 2 inch dia flared port and a tuning frequency of
about 36Hz. I'm very pleased with the result. This requires an amp. Subwoofer "plate"
amplifiers are a good option. Complete details on the project
page.
Small tube speakers
This design uses a 1 inch HiVi tweeter
and a 4 inch Aura speaker
in 5 inch PVC pipe with a port and a passive crossover. The drivers use neodynium magnets
which are stronger than ferrite magnets for their size. The design is still evolving but the
results are encouraging. These speakers performed better than any of the others in the
shootout. Complete details on the project page.
3 inch "full range" speakers
A HiVi B3N
in a 2.5 liter box with a passive filter to shape the response. The baffle it tilted at 12.5
degrees to point at your head when placed on a desk. It sounds pretty good for a $10 speaker.
Moderate bass boost or a subwoofer is desireable. Complete details on the
project page.
Altec MX-5020
- $99 (mine were $75 on sale)
Powered "computer speakers" that are smooth enough to use
on my desktop. They lack bass, have a slight cavity resonance and exhibit vertical beaming at
high frequencies but they were better than anything else I found in my local stores at the
time. I checked out commercial systems that came with subwoofers but their satellite speakers
sounded like large, angry insects.
Klipsch ProMedia Ultra 2.0
- $99.
Bill Wright brought these to the meeting. They have more low frequency output than the Altec
speakers but are not as smooth. They have a tilted baffle to point the high frequencies at
your head so vertical beaming is not a problem. This is probably a better choice for gamers
than the Altec model.
How the project got started
I searched my local stores for a decent subwoofer to complement the Altec speakers. I was very disappointed by what I heard so I decided that I would have to build something worth listening to. In a former life I did live sound and built PA and hifi speakers so it was not too big a stretch. I found a lot of excellent material and advice on the Internet and a couple of books that helped. I ended up giving away the Altec speakers and building my own satellite speakers and a subwwoofer. I'm really glad I did.