Speaker Problem?

[Steveruger45]

I would tend to change the wire too.  It could be somewhat broken inside the insulation. Where it’s broken, who knows.
But you could just try desolder the suspect speaker wire at the speaker, cut it back and restrip the end, tin it and then remove the existing solder on the speaker joint and resolder.  You might be lucky.

[EL3632]

Update:
I resoldered the existing wires, that did not help. I took spare wire from TCS CN decoders and soldered them to the speaker. The front wire had no change, but the back wire did, and it seems to be doing better, but only with the prime mover in idle, anything more and it is still staticky, but much less so, and does not seem to be getting any worse, so hopefully we are on to something! I guess the next step is to try a different speaker. I don't have any spares, so I would have to take a speaker out of another engine and see if that works.

As I have been testing it I found that the decoder is magnetically attracted to the speaker, and the decoder clicks to the top of the speaker. This in turn makes both the decoder and the speaker substantially warmer than they would be otherwise, and the speaker's temperature is a major factor in the static, or so I think. Is this supposed to happen? I assume no, but there is no other place for the decoder in this loco, and putting something in between them would dampen the sound, or at least that is my assumption. There should be room for the decoder to sit straight in and not touch the speaker or get within magnetic range. Not sure if it would be worth pursuing or not, though.

[EL3632]

As I was typing the last post, I let the PA just idle and burble in the background, but I had put it's shell on, all other tests have been with the shell off so far. With the shell on, I went to blow the horn (my surefire test for the static) and it was fine. No static. I am confused. It has been on this entire time (for about 30 minutes at the time of this post).

Regardless, I put it in drive hold and notched it up, I will be monitoring it and seeing if it gets any better or worse, but it seems like that wire was the issue, or at least a large part of it.

[tehachapifan]

While I still think there's a chance that something may be overheating or potentially close to failing, I have found that there are a couple of other things that can cause crackling or a static-like noise. They are:

1) An inadequately-sealed speaker enclosure.

2) The speaker/enclosure is sitting loose in it's cradle or designated spot and is vibrating against the inside of the shell or frame.

Since you describe a sudden improvement with the shell on, perhaps the speaker became a little more secure (this time) and reduced the vibration. I will typically run some Kapton tape from the speaker/enclosure to the frame to reduce play.

[Steveruger45]

As I was typing the last post, I let the PA just idle and burble in the background, but I had put it's shell on, all other tests have been with the shell off so far. With the shell on, I went to blow the horn (my surefire test for the static) and it was fine. No static. I am confused. It has been on this entire time (for about 30 minutes at the time of this post).

Regardless, I put it in drive hold and notched it up, I will be monitoring it and seeing if it gets any better or worse, but it seems like that wire was the issue, or at least a large part of it.

The decoder should not toucH the speaker magnet.  Try glueing a strip of styrene to the speaker enclosureS forward end, and if needed the aft end too,  a little taller than the speaker, such that the decoder is physically held above and clear from touching it, Ive done this on a couple of cramped installs.
Sometimes a speaker can sound a bit buzzy if it’s not solidly installed. I usually put a small spot of ca on the enclosure bottom or end and stick it to the frame. You could use a spot of silicone or Walters goo but you would need to keep it pressed in place and wait until dry.  This will stop any possible enclosure vibration caused by the sound and can easily be removed/pried off when needed.

[EL3632]

I did some more changes before running the unit:
Glued in the speaker with a lot of CA, it sits nicely now, and does not move.
As a result, the speaker and decoder do not touch any more.
Secured the decoder with electrical tape over the rear truck housing, so it does not move. This also helps the decoder not touch the speaker.
After running the unit a bit more, here is what I have now [with shell on]:
The unit will idle forever without any issues.
Once the unit notches up, the speaker gets staticky again, but this time after around 30-45 minutes of run time. This happens when the unit is in Drive Hold at 0 and while actually in motion.
After the unit is in idle for a while, around 2-3 minutes for a long amount of run time (45 minutes), around 10-20 seconds for a short amount of run time (15-20 minutes, the horn got staticky around then, but the prime mover did not) the speaker is fine again. No static, not even from the horn.
Much better, but still not fixed. Replacing the wires to the speaker definitely helped, and actually had me fooled for around 10 minutes thinking the problem was fixed.
I think the speaker is the issue now, though am not sure. I do not have a spare speaker, so I would have to use one from another active unit in order to try this out, or order one. On the speaker front, I am completely clueless, any help is greatly appreciated.

[peteski]

I think the speaker is the issue now, though am not sure. I do not have a spare speaker, so I would have to use one from another active unit in order to try this out, or order one. On the speaker front, I am completely clueless, any help is greatly appreciated.

Maybe @nightmare0331 could give you info about the speaker brand/model and possibly source of them.

If not, if you have a multimeter, you can measure its impedance (actually resistance). It is likely 8 ohms.  If you have a caliper you can also measure its dimensions.  Armed with that info, you can search for a source. I would start at Digikey and Mouser Electronics.

[jdcolombo]

If you can measure the speaker size (length and width), I can give you some suggestions.  Note - make sure you are measuring just the speaker, not the enclosure.  It should be something like 8mm x 12mm, or 11mm x 15mm, or 9mm x 16mm.

John C.

[Steveruger45]

Hmmm.  Interesting. Seems like there were/are a number of  issues on this one.  I wouldn’t give up on the speaker just yet. Did you try drilling a small hole in the enclosure as previously suggest earlier by Kelly?  Forgive me if you already did and I missed it.
It does look like a bad speaker is now top of the Fault possibilities list from what you have found/described. I can understand the frustration You are probably feeling, but it is interesting.

[tehachapifan]

Hmmm.  Interesting. Seems like there were/are a number of  issues on this one.  I wouldn’t give up on the speaker just yet. Did you try drilling a small hole in the enclosure as previously suggest earlier by Kelly?  Forgive me if you already did and I missed it.
It does look like a bad speaker is now top of the Fault possibilities list from what you have found/described. I can understand the frustration You are probably feeling, but it is interesting.

Yes, the hole in the enclosure does seem to be a (sometimes tricky) thing. I often do drill one tiny hole with a #80 twist drill bit in the (otherwise-completely-sealed) enclosure on my custom installs, where I build my own enclosures out of styrene. It is indeed a bit tricky sometimes, as I've had a couple speakers/enclosures crackle until I drilled this hole, and a couple others crackle until I plugged this hole. I think the science behind adding the hole is it allows the speaker diaphragm to move more freely instead of against the pressure inside a completely sealed box, though I'm not positive.

Another semi-related thing is I've had sound quality in one install actually improve as the speaker presumably heats up over time. It starts out with a slight crackle specially with the horn but, after a minute or two of running, the crackling stops. I figure that maybe there's a slight air leak between the speaker and enclosure that seals up better as it warms, Could also be that maybe there's a vibration when cold that improves with heating, perhaps related to expansion. I don't know....complicated stuff sometimes!

[nightmare0331]

Maybe @nightmare0331 could give you info about the speaker brand/model and possibly source of them.

If not, if you have a multimeter, you can measure its impedance (actually resistance). It is likely 8 ohms.  If you have a caliper you can also measure its dimensions.  Armed with that info, you can search for a source. I would start at Digikey and Mouser Electronics.

ESU 50321 11x15 mm speaker and housing 8 ohm.

Hope this helps!

Kelley.
www.dufordmodelworks.com

[jdcolombo]

There are a number of 11 x 15mm speakers available from Digikey/Mouser.  Here are a few:

https://www.digikey.com/product-detail/en/cui-devices/CMS-15113-078SP/102-5644-ND/8581915

https://www.digikey.com/product-detail/en/cui-devices/CMS-151135-078SP-67/102-5003-ND/9561105

https://www.digikey.com/product-detail/en/cui-devices/CMS-151135-078SP/102-4617-ND/8581451

https://www.digikey.com/product-detail/en/pui-audio-inc/AS01508AO-WP-R/668-1515-ND/5958413

https://www.digikey.com/product-detail/en/pui-audio-inc/AS01508AO-3-R/668-1518-ND/5977704

The first three on this list are manufactured by CUI; the last two by PUI.  All have solder pads for wire connections (as opposed to spring clips; I find the solder pads easier to use).  I've personally used the first and third CUI speakers with good results; I think the third one sounds a bit better than the first, but I've never taken actual measurements, so I may be hallucinating.

You would also need an enclosure.  These are all bare speakers.  If you want a pre-made enclosure, you can get a speaker + enclosure here:

http://store.sbs4dcc.com/SBS4DCCSugarCubeSpeaker11x15mm8ohm1wattw/SoundChamber.aspx

If you are willing to construct your own enclosure from .030 styrene, thick CA cement and patience, here's a link on how to do it:

https://www.therailwire.net/forum/index.php?topic=31311.0

John C.

John C.

[peteski]

ESU 50321 11x15 mm speaker and housing 8 ohm.

Hope this helps!

Kelley.
www.dufordmodelworks.com

Ok, so both the speaker and decoder are sold by ESU - that should assure compatibility.  I guess I expected that.

[EL3632]

Thanks for all the information so far guys! I think I will ultimately end up getting a new speaker or two, just to have them, but want to figure out what is up with this one, too. My curiosity and tinkering desire compels me! 

I ran the engine again today after a good 12 hour cool down period. It ran for around 15 minutes then got staticky again, took the shell off and determined everything was as it was prior to the shell getting put on. So far, the wire replacements helped, a lot, but something is still off.

ESU 50321 11x15 mm speaker and housing 8 ohm.

Hope this helps!

It does, thanks! My LHS has some in stock, I will pick some up from there.

There are a number of 11 x 15mm speakers available from Digikey/Mouser.  Here are a few:

[links to Digikey]

The first three on this list are manufactured by CUI; the last two by PUI.  All have solder pads for wire connections (as opposed to spring clips; I find the solder pads easier to use).  I've personally used the first and third CUI speakers with good results; I think the third one sounds a bit better than the first, but I've never taken actual measurements, so I may be hallucinating.

You would also need an enclosure.  These are all bare speakers.  If you want a pre-made enclosure, you can get a speaker + enclosure here:

[link to SBS]

If you are willing to construct your own enclosure from .030 styrene, thick CA cement and patience, here's a link on how to do it:

[link to enclosure thread]

John C.

John C.

Thanks! This will be helpful for when I ultimately start doing more custom sound installs (working on the PA has given me a small amount of confidence, and I want to try it out, so here's hoping!); @ChristianJDavis1 had me build a box out of styrene, to help get my feet wet; and I feel that, with an actual speaker to go around it, I think it will go a lot better.
I was thinking of trying an Atlas U25B, after seeing Central Jersey Conrail in N Scale's videos on doing said installs, it looks pretty straightforward, and something that I think would make a good first custom install.

Did you try drilling a small hole in the enclosure as previously suggest earlier by Kelly?

No, where is the best spot to drill the hole? This is actually the first I have heard of such a technique, and would like to try it, but haven't the slightest clue on how to do it.

Yes, the hole in the enclosure does seem to be a (sometimes tricky) thing. I often do drill one tiny hole with a #80 twist drill bit in the (otherwise-completely-sealed) enclosure on my custom installs, where I build my own enclosures out of styrene. It is indeed a bit tricky sometimes, as I've had a couple speakers/enclosures crackle until I drilled this hole, and a couple others crackle until I plugged this hole. I think the science behind adding the hole is it allows the speaker diaphragm to move more freely instead of against the pressure inside a completely sealed box, though I'm not positive.

Seems like the best place to drill the hole is on the bottom of the enclosure where the diaphragm (term?) is located. Looking at a product picture for the ESU 50321 mentioned above, it comes prepackaged with an enclosure, which appears to be the enclosure used on this speaker. Not sure what the clearances are, nor what it is made of. It does not feel like styrene, though.

[tehachapifan]

On my custom enclosures, I drill the #80 hole on any surface of the enclosure that is not going to be pressed directly against anything, like the frame. I don't think it needs to be inline straight-on with the diaphragm. Plus I wouldn't want to risk the bit slipping through the hole and piercing the diaphragm, assuming the enclosure is already attached to the speaker. I drill the hole in a spot where I know I won't hit any part of the speaker in the process.

I'm sure you know we're talking about the tiny #80 twist drill you use in a pin vice. I've seen large drill bits that go in like a power drill that go by #80 too. That would be bad!