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#81 |
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Join Date: Jul 2011
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![]() Oh yea I do this crap when I do not have the right part sometimes double up capacitors back to back lay them down just to make it fit in the case sometimes it works sometimes it does not
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9 PC LCD Monitor 6 LCD Flat Screen TV 30 Desk Top Switching Power Supply 10 Battery Charger Switching Power Supply for Power Tool 6 18v Lithium Battery Power Boards for Tool Battery Packs 1 XBox 360 Switching Power Supply and M Board 25 Servo Drives 220/460 3 Phase 6 De-soldering Station Switching Power Supply 1 Power Supply 1 Dell Mother Board 15 Computer Power Supply 1 HP Printer Supply & Control Board * lighting finished it * These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10% 1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later ) 2 Hem Saw Computer Stack Board All of these had ![]() All of the mosfet that are taken out by bad caps ![]() |
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#82 | |
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#83 |
Badcaps Veteran
Join Date: May 2011
City & State: Windsor, Colorado
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![]() I tried to fit a different speaker in those computer speakers that smoked a long time ago. The sound quality isn't worth the parts cost (Peerless TC6FC02-04 drivers, on sale at Parts Express for $9.80 each) and the time it took for me to cut those adapters. They sound about the same as the original drivers, but with less bass. However, I haven't changed the driver in the left speaker yet, and the amplifier has a problem with weak bass in one channel that I never figured out.
Last edited by lti; 10-12-2021 at 09:21 PM.. |
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#84 |
master hoarder
Join Date: May 2008
City & State: VA (NoVA)
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![]() ^ Nice!
![]() So wait, you bought those drivers specifically to fix these speakers? ![]() ![]() As for the weak bass... I imagine that is likely caused by a bad cap somewhere - either electrically leaky or high ESR / low capacitance. If you swap the input signals going to each pin on the amplifier IC and the weak bass follows, the issue is before the amp in the signal circuit somewhere. And if the issue doesn't follow, then either bad output coupling or feedback cap in the channel with the weak bass. And if it's neither of those, perhaps the amp is bad. In that case, crank it up to the max and let it smoke itself out?? ![]() Anyways, that modded/repaired speaker looks totally badass like that. Love it! ![]() . . . Unfortunately, I'm too cheap to spend any money when it comes to stuff like that... but NOT time. ![]() ![]() So perhaps if you want to waste even more time with these speakers, you can try to rewind the old smoked drivers, if you still have them. ![]() As for my more recent worthless speaker repairs... I did two speaker surround jobs: one on a single Boston HD8 speaker, and another on a pair of old and kinda crappy Philips speakers. Both of these were too cheap to waste money on surrounds... so I did them the same way I did my good ol' Realistic Nova-18 speakers: made the surround myself from paper. Though on that note, I should say I've improved the "quality" of my surrounds quite a bit. ![]() ![]() ![]() Last edited by momaka; 10-12-2021 at 10:27 PM.. |
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#85 |
Solder Sloth
Join Date: Nov 2012
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![]() Nice... I tend to bin small speaker enclosures with bad drivers, though I have repaired one speaker with bad tinsel wire... fixed with homemade tinsel wire...
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#86 | |||
Badcaps Veteran
Join Date: May 2011
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#87 |
Solder Sloth
Join Date: Nov 2012
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![]() Amplifier in those speakers a single ended (with dc blocking capacitor), bridge, or bipolar driver? Highly doubting bipolar but bridge is possible, else cheaper single ended...
Suspecting the bipolar and bridge configurations have better bass response that won't get eaten by the blocking capacitor? |
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#88 |
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![]() It's single-ended.
Other configurations might still have a DC blocking cap on the input. To make this even more pointless, I have some sound damping foam that I could stick on the inside. ![]() |
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#89 | ||||||||
master hoarder
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![]() Good point!
Heck, making your own enclosures might give better results than the original plastic ones. Actually, weren't you the one that did that before? I remember a picture on BCN from quite a few years back with some home-made enclosures. I think it was yours, but don't remember 100%. Looked pretty cool, though. Quote:
I have a pair of slightly more "premium" stereo computer speakers from the late 90's, and they aren't too bad at all. They use 3.5" (or is it rounded to 4"??) "woofer" drivers going full-range, and a smaller set of 1" drivers for the tweeters. Branded "Saturn", model: SP-632A (and look similar to SP-622/SP-610/SP-5100/SP-500 series if anyone cares to look those up.) Based on a KIA6283k single-ended amp IC. They sound very decent, especially for close proximity listening, like they were intended for. Obviously not going to shake any walls with bass, but go down to 50-60 Hz range with relative ease and flatness in a small room. Some of the late Sony CRT TVs used very similar drivers, and they pumped out pretty good sound. Magnetically shielded too, so my CRTs approve! ![]() Quote:
A lot of the cheaper 2.1 systems have a dual-chamber woofer built with one chamber sealed and the other one ported. The "woofer" driver (typically 3.5-4" cone size) is positioned on the wall between these. Given the small cabinet sizes of these woofers, they have the typical double-humped response, with one peak in the 40-55 Hz range, and the other in the 100-120 Hz range. Their bass response also drops off very sharply below 40-50 Hz, depending on design. So yeah, they do often have a boomy midbass, or at least very exaggerated low-end on voice content. Even then, though, these are still a lot more controlled than on cheap old ported speakers from the 90's. The Realistic Nova-18's mentioned above are actually a prime example of that: they easily go +20dB (or at least sound like it) in the 70-80 Hz range, but drop off quickly below that. "One-note wonders", as some people call them. ![]() ![]() ![]() ![]() Quote:
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So if the output caps are bad (low capacitance and/or high ESR), that can really affect the -3dB cutoff frequency. You can use this tool to see how the capacitance affects the -3dB low frequency cutoff for amps with DC blocking / AC coupling caps on the output: http://sim.okawa-denshi.jp/en/CRlowkeisan.htm Quote:
You should. ![]() Provided you can find thin enameled wire easily. I suppose if you don't mind sacrificing a small DC motor, you can probably get some from there... or scrapped CRT TVs possibly (yoke and focus/pin coils.) Quote:
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As shown with the RC low-pass filter calculator tool above, 8-Ohm load with 1000 uF output cap sets the -3dB at about 20 Hz... which is pretty acceptable. Most of the time, the drivers and the enclosure will be the limitation with such small speaker setup, rather than the output caps... especially on tiny speaker drivers that really can't go down below 50-60 Hz anyways. Might as well block those lower frequencies from going into the driver and wasting power unnecessarily... which could matter in a positive way if the power supply is undersized, as is typically the case with very cheap desktop speakers. Quote:
Actually, the most that will happen from doing this is you might dampen some cabinet resonance/vibration, especially if the enclosures are rattly and cheap. If it's a ported design, though, generally damping will make you loose a few dB (at least with larger speakers... not sure if there would be a difference with small desktop speakers like this.) Last edited by momaka; 10-14-2021 at 12:47 PM.. |
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#90 | ||||
Badcaps Veteran
Join Date: May 2011
City & State: Windsor, Colorado
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These are cheap, but resonance is less of a problem with the new drivers. Putting damping material in modern $10 speakers would be even more pointless, although the set I have sounds better with the speakers in free air than with the speakers inside the enclosure. |
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#91 |
Badcaps Veteran
Join Date: May 2011
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![]() I made my speakers more pointless with a notch filter to get rid of the big hump in the midrange response (I have to use a third-party website because the Peerless datasheets are broken). That 2kHz peak was annoying and caused that "tinny" sound. I haven't trimmed the leads yet because I don't know if I have the correct resistor value yet.
I don't think these drivers are really worth the money once you add in the price of the filter components. There are even other Peerless 2" drivers with flatter frequency response, like the TC6FC00-04 (although the off-axis response looks worse). At least the magnet structure they use has a weak external magnetic field, so they can be used around CRTs. Also, you can see that I still have a 512MB flash drive and my really fast Transcend drive is at the bottom of the pile. ![]() |
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#92 | ||
master hoarder
Join Date: May 2008
City & State: VA (NoVA)
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Yeah, I think the sound would still be "tiny" no matter how many notch filters you have or how big they are. The speaker itself is rated from 150 Hz and up, with a self-resonant frequency around 170 Hz. So it's really more of a mid-range / tweeter driver... and 2" diameter is right for that anyways. Actually, I'm quite surprised that such a small driver can go so "low" in the frequency response. Your notch filter really inspires me to try and do the same to a pair of headphones I found recently for free (they came in a small PC PSU parts lot.) For the most part, I can correct a good deal of their frequency response with an EQ in WinAmp. But TBH, I never really liked how software EQs sounded in Windows (especially when pushed really hard to correct a lot.) So I'm curious to see if a hardware notch filter / band-gap filter could do them better justice or not. They have really really strong bass, which I'm OK with. But the mid-range is even stronger - in fact, so strong that it took me to a while to figure out what exactly needed correcting, since they sounded like listening through tin cans under water - literally! I'm not exaggerating a single bit. After severely attenuating the low-mids and mid-mids, then boosting the low-highs, mid-highs, and high-highs... they sounded... acceptable. ![]() ![]() --------- While on the discussion of speakers/audio... here are two pretty worthless speaker repairs I did (one last summer, and one last spring): Boston Acoustics HD8 https://www.badcaps.net/forum/showthread.php?t=103073 Philips F9217L-50R https://www.badcaps.net/forum/showthread.php?t=103598 These involved replacing rotten foam surrounds on the woofer drivers with home-made / DIY surrounds from paper towel and latex/household paint. Pretty ugly ![]() Quote:
![]() Last edited by momaka; 02-17-2022 at 01:01 AM.. |
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#93 | ||||
Badcaps Veteran
Join Date: May 2011
City & State: Windsor, Colorado
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![]() Quote:
I first thought about doing that around 11 or 12 years ago when Parts Express had a really impressive-looking unbranded 2" driver that they were dumping cheap ($2, if I remember right). I ended up only getting one of those drivers and using it for testing (building something like the old Radio Shack speaker with the built-in amp), and I noticed the foam surround starting to degrade a few months ago. Recently, I saw some speakers from Tang Band that have a 1" driver and a passive radiator in a tiny enclosure, and now I'm thinking about a passive radiator design. I also saw the Tectonic BMR drivers (and I think there was another brand that made a similar driver) that are supposed to have really good off-axis response... ![]() Now I'm thinking of the physics professor I had in college who said that a 15" subwoofer was small. Quote:
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#94 |
Badcaps Veteran
Join Date: Jan 2018
City & State: Central PA
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![]() Sonos bridge. I'm not even a Sonos user so I'm not exactly sure what it does but I think it's an access point for Sonos devices. Has ethernet in the back. Pulled from the trash from work with no signs of life. Can you spot why? 3 new caps and she's as good as new. Never heard of TBor brand before.
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#95 |
Solder Sloth
Join Date: Nov 2012
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![]() Heh I guess that would automatically be called a worthless/useless repair if one doesn't know what the device does and don't expect to ever use or even test the device
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#96 |
Badcaps Veteran
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![]() ToBe OR not to be caps
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#97 |
Badcaps Veteran
Join Date: Jan 2018
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![]() You guys will laugh at this one. Got this old iPitomy phone system from the bin at work. It's basically an intel Atom x86 system with a pico DC-DC power supply. I replaced the motherboard caps that were leaking and some additional with Aliexpress Polys and it works fine.
I troubleshot the power supply for a good month off and on, couldn't figure out why it wouldn't stay running and would go into protection mode. Turns out I was feeding it 19v from a laptop power brick and it needs 12v ![]() |
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#98 | |
master hoarder
Join Date: May 2008
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![]() That's because they are Too Boring.
![]() Though, one of yours looks like it almost launched the way it shot out the bottom away from the bung. ![]() Well, I think we figured which option those caps chose when they failed. ![]() Quote:
I guess he can try to sell it online and recoup back the cost of the caps... and maybe enough for a beer too? ![]() Last edited by momaka; 03-26-2022 at 09:40 PM.. |
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#99 | |
Solder Sloth
Join Date: Nov 2012
City & State: CO
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![]() But wait, I thought boring was good?
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#100 | |
master hoarder
Join Date: May 2008
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![]() Well, I meant as a brand name.
![]() Otherwise, you can see how one of these has popped from its bottom. I'm sure it must have made at least a "muffled" pop inside the case. Definitely NOT boring! ![]() Quote:
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