Computer Speaker Salvage - ID & Suggestions?

[AdamThorne]

Through my job I have come across a bunch of little computer speakers that I can have if I want. Oh boy! Making sound in the office! Or the bedroom! Maybe the basement! You see how I work here.

So I'll include pics of the drivers. The group of appearantly similar Harman / Kardon speakers actually had 2 different kinds of drivers.
The ones on the left have printed on the back:
Samsung
08G11ARH
4 (ohm) 3 w
H309 24

On the right:
004-02
4 (ohm) 5 w
China
2J14D

Can anyone tell me anything about these drivers? After some listening the Chinese one sounds like it has more bottom end and more top end, and greater clarity as well. But it is more forward and harsh sounding than the Samsung unit, which sounds mellow, if indistinct. The Chinese unit might be a bit louder. The dustcap on the Chinese unit is hard, shiny plastic, while on the Samsung it's softer, and a matte finish. This is the main visible difference.

While I had the speakers open I had a look at the amp. The central bit of it was a Philips chip, TDA1517P. I didn't have much difficulty finding an online data sheet on the chip, with a reference design. I plan to yank the chip and rebuild it as an exercise. Can any of the smarties around here possibly suggest improvements on the reference design? It's so simple, it makes me think it leaves something undone...

As far as speaker enclosures go - I'm interested in back-horns at the moment. Ones small enough for cheap experimentation and easy placement. If you look up "Makizou" here at diyaudio you'll find the design I'm thinking of. (evidently it's not strictly a horn, but I'll call it that for lack of a better term) I have no idea if these drivers would be appropriate for that (or any) horn enclosure. I see people talking about horn designs as if it's worth a shot sticking any driver in one, but I don't really know what I'm talking about here, so I'd appreciate some input.

Failing that, maybe a multiple FR driver array...?

[AdamThorne]

gah - preview removed my picture =P

[Stocker]

Wow have I ever been there! Currently I have computer speakers in 1 place: under my bench, to test something with a plug-out (cd player, sound card etc.) and as a general kickaround test sound setup. Everything else has 2.1 component setups. Unless volume and quality are low you will quickly find yourself wanting better speakers. My advice for myself, in your shoes, would be this:

do a low-to-moderate amount of work on these (likely to be poor) drivers, for learning and fun. Do not go overboard on finishing the completed parts. Do not make any permanent modifications to anything you or your SO care about to install this stuff.

If it blows up, laugh.

[Geoff H]

Yeah, the ones on the right look familiar. Like the ones found in Diamond Multi Media desktop speakers. 3" go ok in little QWTLs. Don't expect high spls but can give surprising results for the size.

The little amp will probably have BSC built in. If you put them in new boxes, and keep the width of the plastic boxes, the BSC is done.

Good fun for a wet weekend.

Geoff.

[tburman]

The Samsung drivers you mentioned look and sound quite similar to those I ripped out of my old pair of Creative PC speakers. Mine have a smaller magnet and no mounting flange at all. I'm experimenting with them in 3 foot PVC pipes. They sound surprising for their size. Bass does not rock out, but easy listening is good.

[loninappleton]

How many have you got?

You mentioned line arrays.

I got that deal at Parts Express last year or so on the
50 centers from Pioneer. I built one sample of 8 drivers in the
line.

But you are talking desktop here.

Try a listen with open backs on these small ones. I'm saying a small box with an open back, not some flat board arrangement. If the
enclosure has to be small, a recommended project from Speakerbuilder
used a small driver (and one design in pairs) with a small angled
box and only a scrim (fabric to prevent dust) on the back.


This works if you don't like the 'boom box' sound so common in
shelf systems. I think there's some loading from the wall in such
an arrangement as well.

Years ago GM told me in these forums to knock the backs off of
some mini desktop speakers to clean up the sound. that's pretty much where I started the hobby.

[v-bro]

PVC is cheap and a good dirty way to build fast...

[v-bro]

The previous pic. is with a 2" Visaton FR-7

Or a TL with 3" Visaton FRS-8:

[v-bro]

It is possible to make a lot of shapes by heating it (wear gasmask! or go outside...). It also performs well enough for cheap FR drivers...

And it's rock solid, I built a portable system that a friend uses on his bicycle:

[AdamThorne]

how do you heat it outside? blowtorch? Heat gun? Fire pit?