Suppose I come across random pair of computer speakers (integrated amp, 9v wallwart power, etc). They come in a plastic enclosure. This happens all the time - thrift stores are drowning in them. Dell and co. hand out these things with every new machine. For example, here's just some set I found on Google Image search.
As a beginner project: can they be built into new wooden enclosures? The drivers are probably 100% crap, as well as the amp, and there are likely to be no T-S params or anything that might help with design.
What might one expect in rebuilding such a thing to a stiffer wooden case, how would one determine enclosure volume, and could any improvement really be found by rebuilding the enclosure of such fleamarket junk?
An externally hosted image should be here but it was not working when we last tested it.
As a beginner project: can they be built into new wooden enclosures? The drivers are probably 100% crap, as well as the amp, and there are likely to be no T-S params or anything that might help with design.
What might one expect in rebuilding such a thing to a stiffer wooden case, how would one determine enclosure volume, and could any improvement really be found by rebuilding the enclosure of such fleamarket junk?
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I suggest you to start from the begining with a new project. The speakers itself, but the magnet, are made of PLASTIC! The "power amp" is about 3W peak (From a 9V power supply).
Enjoy making a new onw one by yourself, and at your taste. It is not a difficult task.
Enjoy making a new onw one by yourself, and at your taste. It is not a difficult task.
You can do so much better with not much money. Here is a link to a funky pair of computer speakers and the drivers were only 8 bucks a piece and here is a pic of my computer speakers that cost me 300 bucks in parts.
http://www.diyaudio.com/forums/full...ge-speaker-photo-gallery-344.html#post4537606
http://www.diyaudio.com/forums/full...ge-speaker-photo-gallery-344.html#post4537606
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echo all of the above - a couple of questions immediately pop into mind:
1) budget - for both speakers and amp?
2) do you have space to keep the amp outbotpfvthe enclosures? that'd be at the top of my check list for a small prject
1) budget - for both speakers and amp?
2) do you have space to keep the amp outbotpfvthe enclosures? that'd be at the top of my check list for a small prject
hornpipe2:
Reading "between the lines", will it be correct to say that you are more attracted to wood working rather than to electronics?
Is that the reason you prefer to take a ready made circuit+drivers, instead of buying the parts and connecting them?
You should know that there are ready-made amplifiers - a PCB with all needed components soldered to it.
Also you can buy the drivers, from many places, inc. eBay, for really fair prices.
The quality you will get from such simple PC Speakers is literally garbage, forgive me for the blunt word,
but no other way to describe it.
That's why people say it's not worth the work around it, regarding the enclosure..
Reading "between the lines", will it be correct to say that you are more attracted to wood working rather than to electronics?
Is that the reason you prefer to take a ready made circuit+drivers, instead of buying the parts and connecting them?
You should know that there are ready-made amplifiers - a PCB with all needed components soldered to it.
Also you can buy the drivers, from many places, inc. eBay, for really fair prices.
The quality you will get from such simple PC Speakers is literally garbage, forgive me for the blunt word,
but no other way to describe it.
That's why people say it's not worth the work around it, regarding the enclosure..
Most all of these have the TDA2822 chip-amp...I have "repurposed" a pair of these, ditching the cheap a** driver , enclosure . At 600mW or so, you have plenty of power, IF you develop a pair of truly highly sensitive speaker sets. At this very moment, I'm listening to Ozzie with one of my "new" amps...more than loud enough, even a 12" DVC subwoofer!
Reaching for even more SPL, one could even work up something with so-called "guitar speakers". Remember, those crappy drivers in the original plastic enclosures are likely rated at less than 85 Db@1W.....useless for anything but talked speech.
Pull the amp board out, find an appropriately sized (tiny) plastic enclosure lying around, put some proper output terminals, maybe keep the stereo minijack .as I had done.....for computer, tablet....or as I,m now listening thru, Ozzie on a portable CD player piped thru this amp,..but with a wall wart for power.
.....................................................Rick..........
Reaching for even more SPL, one could even work up something with so-called "guitar speakers". Remember, those crappy drivers in the original plastic enclosures are likely rated at less than 85 Db@1W.....useless for anything but talked speech.
Pull the amp board out, find an appropriately sized (tiny) plastic enclosure lying around, put some proper output terminals, maybe keep the stereo minijack .as I had done.....for computer, tablet....or as I,m now listening thru, Ozzie on a portable CD player piped thru this amp,..but with a wall wart for power.
.....................................................Rick..........
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Thanks for the tips, everyone. I was hoping to build something just as small but it sounds like the main problem is going to be the drivers. So I might look for a better setup.
Some of them are worth a try. I sometimes pick up junk speakers just for parts - for example, if someone is throwing out some OK looking boxes, I might salvage the binding posts and crossover parts.
With computer speakers, some of the little amps are good, and some of them are hissy and terrible - they only get away with it because the stock speakers have such low efficiency. If you plug bigger / more efficient speakers into them, the noise levels become more obvious.
Some drivers that look like garbage can be quite fine. You really have to try them and see.
The image is the free-air measure of some 4" drivers, mic at about 50cm. I was going through a stack of them to see what to keep / give away / discard.
The black line was a flimsy, cheap looking thing from an old boombox.
The relatively shonky blue line with the 7kHz spike is a fairly new Fostex driver ($80 each, in Australia).
I think I'll keep the Fostex units purely as a reference - anything better gets saved, anything worse goes in the bin.
At a very rough guess, about 20% of free / salvage drivers measure (and sound) better.
With computer speakers, some of the little amps are good, and some of them are hissy and terrible - they only get away with it because the stock speakers have such low efficiency. If you plug bigger / more efficient speakers into them, the noise levels become more obvious.
Some drivers that look like garbage can be quite fine. You really have to try them and see.
The image is the free-air measure of some 4" drivers, mic at about 50cm. I was going through a stack of them to see what to keep / give away / discard.
The black line was a flimsy, cheap looking thing from an old boombox.
The relatively shonky blue line with the 7kHz spike is a fairly new Fostex driver ($80 each, in Australia).
I think I'll keep the Fostex units purely as a reference - anything better gets saved, anything worse goes in the bin.
At a very rough guess, about 20% of free / salvage drivers measure (and sound) better.
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"hornpipe2" I would say it's worth a try. Perhaps you have seen my threads http://www.diyaudio.com/forums/multi-way/287392-new-enclosures-pc-speakers.html and http://www.diyaudio.com/forums/chip-amps/283845-pc-speaker-electronics-amplifier-conversion.html ?
It's been a fascinating and rewarding exercise- take these PC speakers, remove the speaker drivers from the plastic casing and try out all sorts of enclosures - corrugated cardboard, hardboard, open baffle and so on. You may be amazed at the sound of the 'liberated' PC speakers, I was. It's a great first step to adding a subwoofer and completing out the sound.
As for the amplifier board inside, this, too was a total surprise. I have tested it out with large 3 way hi fi stereo speakers, and while it cannot match the power (careful dont damage your speakers) it sounds very listenable.
I think this is the ideal introduction to building your own system - go for it!
It's been a fascinating and rewarding exercise- take these PC speakers, remove the speaker drivers from the plastic casing and try out all sorts of enclosures - corrugated cardboard, hardboard, open baffle and so on. You may be amazed at the sound of the 'liberated' PC speakers, I was. It's a great first step to adding a subwoofer and completing out the sound.
As for the amplifier board inside, this, too was a total surprise. I have tested it out with large 3 way hi fi stereo speakers, and while it cannot match the power (careful dont damage your speakers) it sounds very listenable.
I think this is the ideal introduction to building your own system - go for it!
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