Full disclosure - I'm more of a vintage computer guy, and I'm very much a noob when it comes to audio stuff.
So I have a set of old PC speakers that I like the look of as they match my old computers, but they're pretty much toast. Even when they were brand new they wouldn't have sounded too good.
So in short, I want to rip all the guts out of them (amp, speaker cones, etc) and replace them with something newer and better sounding. My problem is I have absolutely no idea where to begin. I've tried looking up guides and tutorials online, but there doesn't seem to be anything I can find for what I specifically want to do. (Speakers AND amp all together in one unit)
Here are some pictures for what I'm dealing with:
20201203-192328 — ImgBB
20201203-184428 — ImgBB
20201203-184345 — ImgBB
20201203-184343 — ImgBB
20201203-184337 — ImgBB
(The knobs have already been removed from the pots in these pictures)
Note the plastic fake dummy tweeter!
It looks like something that should be in theory straightforward: just source equivalent components and swap them out!
However, I just have no idea how to evaluate what is suitable and what's not.
Some specific concerns of mine:
* Make sure the pots and power button line up
* Make sure I can hook up the power LED
* The amp board needs to accept the correct input and have an output to go to the left speaker
* What sort of power supply do I need?
* Does the amp need special separate outputs for the woofers and the tweeters?
Since this will be hooking up to old computer hardware, I don't really need absolutely top of the line components, but I still want it to sound reasonably good.
So I would really appreciate some help, just getting me on the right path. I don't mind doing my own research, but in this case I just have no idea where to even start!
So I have a set of old PC speakers that I like the look of as they match my old computers, but they're pretty much toast. Even when they were brand new they wouldn't have sounded too good.
So in short, I want to rip all the guts out of them (amp, speaker cones, etc) and replace them with something newer and better sounding. My problem is I have absolutely no idea where to begin. I've tried looking up guides and tutorials online, but there doesn't seem to be anything I can find for what I specifically want to do. (Speakers AND amp all together in one unit)
Here are some pictures for what I'm dealing with:
20201203-192328 — ImgBB
20201203-184428 — ImgBB
20201203-184345 — ImgBB
20201203-184343 — ImgBB
20201203-184337 — ImgBB
(The knobs have already been removed from the pots in these pictures)
Note the plastic fake dummy tweeter!
It looks like something that should be in theory straightforward: just source equivalent components and swap them out!
However, I just have no idea how to evaluate what is suitable and what's not.
Some specific concerns of mine:
* Make sure the pots and power button line up
* Make sure I can hook up the power LED
* The amp board needs to accept the correct input and have an output to go to the left speaker
* What sort of power supply do I need?
* Does the amp need special separate outputs for the woofers and the tweeters?
Since this will be hooking up to old computer hardware, I don't really need absolutely top of the line components, but I still want it to sound reasonably good.
So I would really appreciate some help, just getting me on the right path. I don't mind doing my own research, but in this case I just have no idea where to even start!
More info please.
1 - cabinet plays a large part in speaker quality - existing cabs will seriously limit any improvement.
2 - The plastic case is made to fit the main driver - any replacement would have to be an identical match.
3 - not clear on if your speakers have a working tweeter or a dummy tweeter? Are you intending to find a tweeter to fit? See note 2.
4 - do the existing speakers have an internal or external power supply? Do you intend to re-use or replace it? If reuse, what voltage?
5 - what are the 3 controls? I'm only familiar with 2 - vol & tone.
Only when you have studied & researched the above can anyone help.
1 - cabinet plays a large part in speaker quality - existing cabs will seriously limit any improvement.
2 - The plastic case is made to fit the main driver - any replacement would have to be an identical match.
3 - not clear on if your speakers have a working tweeter or a dummy tweeter? Are you intending to find a tweeter to fit? See note 2.
4 - do the existing speakers have an internal or external power supply? Do you intend to re-use or replace it? If reuse, what voltage?
5 - what are the 3 controls? I'm only familiar with 2 - vol & tone.
Only when you have studied & researched the above can anyone help.
The quality of sound is pretty much limited by the small, plastic enclosure.
I would retain the existing electronics and focus simply on sourcing a better quality main driver to fit the existing aperture and mounting points.
Any sound improvement will be hit or miss, but you could experiment with open, closed or lengthened port. You could also apply some heavy felt to the enclosure walls to help dampen their vibrations.
I would retain the existing electronics and focus simply on sourcing a better quality main driver to fit the existing aperture and mounting points.
Any sound improvement will be hit or miss, but you could experiment with open, closed or lengthened port. You could also apply some heavy felt to the enclosure walls to help dampen their vibrations.
To echo what has been said by others before me, i’d be doing a new cabinet for the bits that come out of those plastic boxes.
The boxes are familiar but it is likely more than 1 OEM driver was used during the lifespn of the product, but the drivers in the ones i have disassembled had potential.
The pictures are kind of small. How big is the driver, and could we get pics of the backside? Also pics of the amp (so that we can see the nuber of the (likely) chip amp on it.
dave
The boxes are familiar but it is likely more than 1 OEM driver was used during the lifespn of the product, but the drivers in the ones i have disassembled had potential.
The pictures are kind of small. How big is the driver, and could we get pics of the backside? Also pics of the amp (so that we can see the nuber of the (likely) chip amp on it.
dave
To improve the sound of those yellowing plastic fantastics, I would recommend small 3.5, 4 or 5.25 auto coaxial speakers (whatever fits your holes). They tend to be less sensitive about enclosures, have sufficient tweeters and good sensitivity. You can test them with an external amp so you can see that they work in your enclosures and then connect them to the internal amp to see if it’s going to be sufficient. If the internal amp doesn’t sound good you can power them externally or replace the internal amp with a small class d.
The OP wants to preserve those plastic boxes, Dave, because they match his old computers. He's a vintage computer guy!
If the electronics work, I would focus on replacing the driver as per Indigent Audio's suggestion and, in addition, would line the walls of the plastic enclosure.
I knew I'd forget some important details haha!
Here are some additional photos (you should be able to click on them for larger size):
Amplifier:
20201204-081442 — ImgBB
20201204-081451 — ImgBB
20201204-081504 — ImgBB
Power supply:
20201204-081532 — ImgBB
Back of driver:
20201204-083411 — ImgBB
in response to russc:
1. I'm fond of the boxes, and since they'll only be attaching to old 90s soundcards, I hope they won't be too much of a sound quality bottleneck
2. The way these boxes are designed, it looks like I have tiny bit of wiggle room when it comes to the size/shape of the drivers. I'm OK with tools, so I'm pretty confident I can make some minor adjustments to make things fit
3. There is just a blank plastic plate where the tweeter should be. I would like to use a proper tweeter (while I'm already in there, why not?)
4. There is an existing power supply (see photo above). It doesn't have any markings, and I'm having trouble getting a good reading with my multimeter to find out its voltage.
5. The controls are Volume, Bass and Treble.
So what I'm hearing is I'm better off just keeping the power supply and amplifier board and just replacing the drivers (probably with automotive ones), and maybe add some dampening to the inside as well.
That sounds good to me!
My main question now I guess is:
Since I want to hook up tweeters where there currently are none, can I simply attach the wires to the same terminal that the main drivers are using?
Another issue is that currently the left speaker barely works. Wouldn't be a problem if I was replacing everything, but if I'm going to keep the electronics then I don't know if it's a wiring issue, if the driver is shot or there's something wrong on the amp (blown cap? can't see any, but could be). Whatever it is though I'm sure it will become obvious when I start swapping drivers out, and it's something I can hopefully fix fairly easily
Here are some additional photos (you should be able to click on them for larger size):
Amplifier:
20201204-081442 — ImgBB
20201204-081451 — ImgBB
20201204-081504 — ImgBB
Power supply:
20201204-081532 — ImgBB
Back of driver:
20201204-083411 — ImgBB
in response to russc:
1. I'm fond of the boxes, and since they'll only be attaching to old 90s soundcards, I hope they won't be too much of a sound quality bottleneck
2. The way these boxes are designed, it looks like I have tiny bit of wiggle room when it comes to the size/shape of the drivers. I'm OK with tools, so I'm pretty confident I can make some minor adjustments to make things fit
3. There is just a blank plastic plate where the tweeter should be. I would like to use a proper tweeter (while I'm already in there, why not?)
4. There is an existing power supply (see photo above). It doesn't have any markings, and I'm having trouble getting a good reading with my multimeter to find out its voltage.
5. The controls are Volume, Bass and Treble.
So what I'm hearing is I'm better off just keeping the power supply and amplifier board and just replacing the drivers (probably with automotive ones), and maybe add some dampening to the inside as well.
That sounds good to me!
My main question now I guess is:
Since I want to hook up tweeters where there currently are none, can I simply attach the wires to the same terminal that the main drivers are using?
Another issue is that currently the left speaker barely works. Wouldn't be a problem if I was replacing everything, but if I'm going to keep the electronics then I don't know if it's a wiring issue, if the driver is shot or there's something wrong on the amp (blown cap? can't see any, but could be). Whatever it is though I'm sure it will become obvious when I start swapping drivers out, and it's something I can hopefully fix fairly easily
You would need to wire a bipolar (non-polar or NP) capacitor in line with the positive wire going to the tweeter. A suitable value may be 2.2uF.
If you swap the left speaker driver with the one in the right speaker, you will be able to ascertain if it is the speaker driver that is faulty and not the amplifier.
If you swap the left speaker driver with the one in the right speaker, you will be able to ascertain if it is the speaker driver that is faulty and not the amplifier.
Having said that, look again at Indigent Audio's suggestion of using a driver with a coaxial tweeter built in.
Like these (or similar of the appropriate diameter): JVC CS J420X 10 cm 2-Way Coaxial Speaker – Black: Amazon.co.uk: Electronics
P.S. Your images still don't get any larger!
Like these (or similar of the appropriate diameter): JVC CS J420X 10 cm 2-Way Coaxial Speaker – Black: Amazon.co.uk: Electronics
P.S. Your images still don't get any larger!
Take care about the impedance of the speaker and the embeded maybe fragile power supply. Are these pc boxes have 4 homs or 8 ohms drivers ?
If a better picture of the electronic board could be shot, perhaps there is a room for cheap improvment there : too old caps refurbishing maybe if needed with more "vivid" caps if some are involved in power supply smoothing ? Do those speakers have a plug for a wall, a wall-dart ?
But one of the fun and charm of old stuffs is to keep them vintage...
If a better picture of the electronic board could be shot, perhaps there is a room for cheap improvment there : too old caps refurbishing maybe if needed with more "vivid" caps if some are involved in power supply smoothing ? Do those speakers have a plug for a wall, a wall-dart ?
But one of the fun and charm of old stuffs is to keep them vintage...
Some great tips, thanks everyone!
Gah... linking images in message boards has always been a weirdly specific achilles heel of mine!
Not a perfect solution, but you can see all the pictures here
I guess the appeal of having a separate tweeter is simply the fact that there's already a spot for one! I dunno, I get fixated on these stupid details sometimes.
diyiggy:
The speakers plug into the wall with just a small plug like you'd find on the end of an extension cord - no wall wart or anything. Just two poles, no ground.
There doesn't seem to be any markings for ohms on the speakers, but with my multimeter I get a reading of 4.5 ohms (so I guess that should be 4 ohms?)
I can get a better picture of the board if you want. Would a bigger close-up of the caps help? I might go and replace as many of them as I can - I still have a few leftover Nichicons from another project that might have the correct values.
Galu:
Thanks for the tip on the capacitor to the tweeter! Definitely something I would not have thought of.
Gah... linking images in message boards has always been a weirdly specific achilles heel of mine!
Not a perfect solution, but you can see all the pictures here
I guess the appeal of having a separate tweeter is simply the fact that there's already a spot for one! I dunno, I get fixated on these stupid details sometimes.
diyiggy:
The speakers plug into the wall with just a small plug like you'd find on the end of an extension cord - no wall wart or anything. Just two poles, no ground.
There doesn't seem to be any markings for ohms on the speakers, but with my multimeter I get a reading of 4.5 ohms (so I guess that should be 4 ohms?)
I can get a better picture of the board if you want. Would a bigger close-up of the caps help? I might go and replace as many of them as I can - I still have a few leftover Nichicons from another project that might have the correct values.
Galu:
Thanks for the tip on the capacitor to the tweeter! Definitely something I would not have thought of.
OK, in that case the cabinet needs to be improved. Will take some cleverness.
From the front the driver looks like an FE103 variant, the back less impressive. It looks to be a 100mm/4”, can you put a tape across it?
The not-a-tweeter is a ploy to make it look like a 2-way from the outside. From the back it looks like it could be a piezo, but i se eno wires going to it.
Here is one way to deal with the XO. Frugal-phile | Piezo Tweeter Crossovers | J Risch
So if you want to swap for a much better driver, the next question is what is the volume inside?
dave
I’ll go in and fix those. He is trying to link to Igmur pages with a thumbnail, but the forum software is only paying attention to the thumbnails.
dave
diyAudio moderation team
edit: the images are huge, so the link below each thumbnail gets you to the big picture
I really would prefer to avoid an external amp. It would just annoy me to have knobs on the front of the speaker that don't do anything. Would the existing amp be improved substantially by replacing the caps with proper audio grade ones? I guess there's not much I can do about the chip.
If not, maybe I should go back to my original plan of replacing the current board with a brand new one.
Planet 10:
Definitely not a piezo. Just a hunk of plastic!
Maybe I don't need tweeters, but my brain is fixated on filling those spots with something that works. It's going to happen whether I need them or not!
The internal dimensions are ~14cm x 13cm x 20cm (Depth, width, height)
The woofers are 4", and the "tweeters" are 2".
Just googled FE103 drivers - they do indeed look the same from the front, but quite different from the back.
I just want to reiterate though, these are going to be attaching to vintage sound cards from the 90s. Currently the speakers are the weakest link in terms of fidelity, but after a point I think any improvements will be wasted money, as the sound quality will be limited by the sound card.
I think my plan currently stands at:
* recap the amp (if it's worth it)
* replace the drivers with something newer (and actually functional!)
* add something (felt?) to the inside to dampen the sound
Small class D amp board.
You might be able to strip parts & cut traces on the existing PCB whilst leaving the controls in place. Use jumper wires for the controls after first removing any controls on the new amp.
DC 12V~24V TPA3116D2 2x80W Dual-Channel Stereo Digital Power Amplifier AMP Board | eBay
No mounting holes so just hot melt glue it to the top of the stripped old PCB.
You might be able to strip parts & cut traces on the existing PCB whilst leaving the controls in place. Use jumper wires for the controls after first removing any controls on the new amp.
DC 12V~24V TPA3116D2 2x80W Dual-Channel Stereo Digital Power Amplifier AMP Board | eBay
No mounting holes so just hot melt glue it to the top of the stripped old PCB.
As far as I can see, you still haven't confirmed whether that is due to a faulty left speaker or a faulty left channel of the amplifier.
Swapping the speaker drivers over will reveal the culprit, as I suggested earlier.
3.6 litre. Small for a 4”, ideal for some Alpair 6.2m (metal), but A6.2p (paper) could also fit. No need for a tweeter. These are amoungst the very best FR drivers available in this size (an IMO smoke the FE103 [FE103 SOL excluded]).
Both discontinued but d’Archer still has some A6m
Mark Audio 6M
The vent would likely need tweaking, bass resonse anechoic expected to be circa low 60s, F6, low 50s F10. Very good mids and extended top.
You will have to work the box over to come near getting the most out of the drivers. Get the amp good enuff and people will be stunned when you fire them up.
An adaptor may be needed, but the large bezel on these MA Alpairs makes them closer bezel size to common 4”.
https://frugal-phile.com/boxlib/markaudio/A6x-dims.pdf
Exact dimensions of the cutout and the bolt circle (or how far apart in the case of the tweeter).
As to the amp, yours could be toroughly reworked with caps etc, how much could be squezzed out depends alot on the chip under that heat sink. And rework the power supply, that can make for huge benefits. How good a chip amp can be (depending of course on chip) from crappy to really quite good depending on what surrounds it and the implementation. Yours is cheap so compromises on parts supply, everything.
I expect you could get a solid 1-2 w out of it.
The small Class D amps are a very good suggestion. Easiest if you lose the tone controls. I had/have some tiny (really small) Dayton that were surprising good.
If you want to go over the top, a diy preamp specifically designed to purpose driving separate Class A amps outside the box.
Done right one could get a lot of WTF when people come over and listen.
dave
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