Hello,
Some two years ago I built speakers and made a decision to wind inductors myself. Not the greatest speakers by any means, but they're mine.
About a month ago, they started to act weird, - the bass driver in one of the speakers started to sort of lose connection - like headphones with broken cable. After a week of this on-off issue nonsense, the other one gave up too! Thought maybe the amp is going (never doubting yourself, right?) but upon opening one of the speakers - I noticed that the inductor, which I soldered directly on the driver terminal has come off.
Funnily enough, the other speaker has the exact same issue.
So I have few ideas as to what could be the cause and hoping, anyone can rule out one or more.
1. I did a poor job of soldering the inductor to driver (If I'm allowed to say so, I know how to solder (but not too bright with electronics 😀 ), been doing it for a long time and am aware of how cold solder joints are made). But maybe the copper wire and enamel is playing a role here? I did clean it off and anything remaining should have burned off.
2. The inductor got hot enough to cause it to fail eventually.
3. My amp is pushing large current through terminals which cause excessive heat? (this is pure guess without any backing)
The inductor is 0.793mH - not sure what else is of importance, so please ask.
I did jump the gun and got a new amp working on a foolish assumption that the speakers were fine, and now I'm a bit hesitant to connect them to the new amp if I just solder back the inductors.
p.s. At the time I finished the speakers, I checked the resistance and everything looked exactly according to calculations.
Regards
Some two years ago I built speakers and made a decision to wind inductors myself. Not the greatest speakers by any means, but they're mine.
About a month ago, they started to act weird, - the bass driver in one of the speakers started to sort of lose connection - like headphones with broken cable. After a week of this on-off issue nonsense, the other one gave up too! Thought maybe the amp is going (never doubting yourself, right?) but upon opening one of the speakers - I noticed that the inductor, which I soldered directly on the driver terminal has come off.
Funnily enough, the other speaker has the exact same issue.
So I have few ideas as to what could be the cause and hoping, anyone can rule out one or more.
1. I did a poor job of soldering the inductor to driver (If I'm allowed to say so, I know how to solder (but not too bright with electronics 😀 ), been doing it for a long time and am aware of how cold solder joints are made). But maybe the copper wire and enamel is playing a role here? I did clean it off and anything remaining should have burned off.
2. The inductor got hot enough to cause it to fail eventually.
3. My amp is pushing large current through terminals which cause excessive heat? (this is pure guess without any backing)
The inductor is 0.793mH - not sure what else is of importance, so please ask.
I did jump the gun and got a new amp working on a foolish assumption that the speakers were fine, and now I'm a bit hesitant to connect them to the new amp if I just solder back the inductors.
p.s. At the time I finished the speakers, I checked the resistance and everything looked exactly according to calculations.
Regards
These are definitely possibilities. On the other hand there is vibration, combined with the heavy gauge wire with little compliance, attached to heavy inductors.
A LPF inductor in a speaker xover network might be somewhat heavy and needs to be fastened securely. So I think yours may have become loose JUST due to the rattling and shaking woofers.
Best regards!
Best regards!
Thank you for the quick responses! I think that is entirely possible. What I do find strange however, is that during the 2 year period they have been used on daily basis, both failed within a month. On the other hand, that is strange no matter what is the actual reason for this.
Do you maybe know from the experience if inductors can get anywhere near the temperature needed to soften the solder?
And most importantly, - I'm eager to know if they are safe to connect to the new amp. But as long as resistance of the speaker is within the amps capabilities it should be fine, no?
Even if the inductors disconnect again (I will try to place them separately to not have them hanging off of low freq vibrating speaker), assuming it's some other cause which is bound to repeat.
Out of the few components in XO, I would suspect the resistor for flattening to de-solder, which in my case is perfectly fine.
Do you maybe know from the experience if inductors can get anywhere near the temperature needed to soften the solder?
And most importantly, - I'm eager to know if they are safe to connect to the new amp. But as long as resistance of the speaker is within the amps capabilities it should be fine, no?
Even if the inductors disconnect again (I will try to place them separately to not have them hanging off of low freq vibrating speaker), assuming it's some other cause which is bound to repeat.
Out of the few components in XO, I would suspect the resistor for flattening to de-solder, which in my case is perfectly fine.
They surely won't get this hot to melt the solder. Prior to such an event the wire's enamel would got up in flames within the winding where the wire basically gets much warmer than at the ends.
I strongly support my theory: Same (missing) fastening, same duration of daily use, same soldering way = same (more or less) time of desintegration 😀.
Best regards!
I strongly support my theory: Same (missing) fastening, same duration of daily use, same soldering way = same (more or less) time of desintegration 😀.
Best regards!
Thank you @Kay Pirinha and AllenB! Your guess about the vibrations now seem a lot more likely than what I initially suspected! That is soothing.
Will wire them on a separate board and fasten them down. The internal padding is reason why I hesitated to mount anything near the fluffy, very flammable looking stuff, but surely it can be done safely.
Have a good one!
Will wire them on a separate board and fasten them down. The internal padding is reason why I hesitated to mount anything near the fluffy, very flammable looking stuff, but surely it can be done safely.
Have a good one!
On a side note, since I have a new amplifier now and don't even know if it works, I want to at least test it with headphones. Question - can I do so without speakers attached?
I remember an old wisdom, that you should never power up an amp without speakers connected, but that might as well be from the vacuum tube days (Which my amp does not have).
I remember an old wisdom, that you should never power up an amp without speakers connected, but that might as well be from the vacuum tube days (Which my amp does not have).
Headphones are speakers.
Solid state amps have no problem running with no load, but tube amps may.
Solid state amps have no problem running with no load, but tube amps may.
Hello,
If you are using an amp with a headphone output, no problem. If you are putting headphone directly on the amplifiers output, watch out. Headphones are hundreds of times more efficient than speaker, you could easily blow your headphones (and ears).
Search the web and you will find those that put together resistor dividers so they could safely directly drive headphones.
If you are using an amp with a headphone output, no problem. If you are putting headphone directly on the amplifiers output, watch out. Headphones are hundreds of times more efficient than speaker, you could easily blow your headphones (and ears).
Search the web and you will find those that put together resistor dividers so they could safely directly drive headphones.
I have had components melt their own solder, I can't remember if I've done it with speakers but I've had speaker inductors fry their own varnish and short themselves.
If you attach a heavy lead (inductor lead) the vibration may break it or the terminal, let alone the solder joint. Always prefer flexible leads, even if it's just a small section that you add for the purpose.
If you attach a heavy lead (inductor lead) the vibration may break it or the terminal, let alone the solder joint. Always prefer flexible leads, even if it's just a small section that you add for the purpose.
For my two bits worth, make sure to physically wrap around the speaker solder tag with the conductor or the wire lead from the inductor to ensure a proper physical connection, too often a 'just touching' solder joint will develop into a crazed solder connection that is subject to vibration. Solder itself is not entirely non resistive.
C.M
C.M