Popping noise when turning on

[Ingo]

Hello all,

my Aeon i's have developed a strange behaviour: When I turn on the amp (which is a Musical Fidelity M6i), they make a sharp popping/crackling noise. The amp is only powering the panels (bass is handled by Crown amp wired directly to the woofers). The amp also has a built-in delay (speaker output is only switched on by a relay some seconds after turning the amp on - as most amps do) and other speakers do not pop with the same amp.

Could this be from the charging circuitry turning on within the speakers? These electronics also procduce a distinctive hiss which is audible form within a foot or so from the speakers.

Are there things known to go wrong within the charging circuit over time? Think aging capacitors or the like? These speakers are 20 years old now (panels are new, though).

Any ideas or experiences?

Thanks!

 

[Jazzman53]

I would swap out the panels. If the pop/hiss follows the panel, fault lies there. If not; the fault is likely in the HV bias supply, possibly a cold solder joint or leaky capacitor.

Since I've never owned a ML speaker, I don't know how the panel is mounted in the frame-- but any ESL has three wires from the power supply (transformer & HV bias supply) feeding the panel, and those wires will likely have quick-connectors.

If you can access those connectors, then you won't have to remove the panel for this test... just run jumpers from the good speaker's power supply to the panel on the bad speaker.

 

[Ingo]

Thank you. Both speakers show the same behaviour, one of the a little more than the other.

Also: the popping only occurs if the speakers have been off for some time / overnight, i.e. discharged. If I play music, switch off the amp and switch it back on after a short while, there is no pop.

Which leads me to suspect there is something wrong with the power/bias supply. But on both speakers at the same time? Unlikely...

Speakers have been in storage for several years, though. Only recently I installed new panels and did the "active bass" conversion.

 

[audioxcel]

Are the speakers exposed to high humidity or dust either environmental or a nearby source in the household?

You might try covering them with linen sheets overnight and see if the problem is still present the next day..

 

[Jazzman53]

If you recently installed new panels, they should be good. I would inspect the bias supply circuit board for corrosion.

 

[DanR]

Hi Ingo
Do you by chance have another amp or receiver that you can put in place of the musical fidelity amp to see if that may be the problem, the audible hiss makes me think it could be something in the amp causing this. How old is this amp?

 

[DanR]

I know you said other speakers don’t do the popping thing. Have your Logans done this from the first time you fired them up after the new panel installation or something that developed after a period of time. Also what speaker wire are you using.

 

[Ingo]

Hi Ingo
Do you by chance have another amp or receiver that you can put in place of the musical fidelity amp to see if that may be the problem, the audible hiss makes me think it could be something in the amp causing this. How old is this amp?

I don`t, right now. However. the hiss is there also with the amp diconnected. The amp is about 10 years old.

 

[Ingo]

I know you said other speakers don’t do the popping thing. Have your Logans done this from the first time you fired them up after the new panel installation or something that developed after a period of time. Also what speaker wire are you using.

No, this developed recently. Also, it only does it on a "cold start" of the speakers. Not when they have been used recently (same day).

I am using solid core speaker wire.

 

[Ingo]

Are the speakers exposed to high humidity or dust either environmental or a nearby source in the household?

You might try covering them with linen sheets overnight and see if the problem is still present the next day..

Not really. We have a dog, though, so I supected dog hair getting in the panels - what do you think?

 

[DanR]

I don`t, right now. However. the hiss is there also with the amp diconnected. The amp is about 10 years old.

Ok yep it sure sounds like the problem is with the speaker and not any associated equipment. Being that the speakers are 20 years old the problem could lie within that internal power supply board. The fact that both speakers do this though is perplexing.

 

[audioxcel]

Not really. We have a dog, though, so I supected dog hair getting in the panels - what do you think?

Hairs and dust could definitely cause snapping and popping sounds. Hairs might cause sounds that might resolve after a short period of play but dust is less likely to do that. Try vacuuming the panels and see if the problem is resolved.

 

[Ingo]

Hairs and dust could definitely cause snapping and popping sounds. Hairs might cause sounds that might resolve after a short period of play but dust is less likely to do that. Try vacuuming the panels and see if the problem is resolved.

You mean - like this? My other thread...

 

[Tosh]

Have you ruled out the Musical Fidelity amp causing the popping?
An amp with a bit of DC offset would make a pop at turn-on....

 

[Ingo]

Yes, I did. It doesn't pop with other speakers. Also, it has a delay to prevent just that (I think, or is there any other reason for a delay circuit?). What's more, there is no popping noise if the speakers had been used recently, i.e. if the panels are still charged. It happens only on a "cold start". That's what makes me think it could be the music sensing/charging circuit.

 

[Tosh]

Do other amps make your Aeon i pop?

Which leads me to suspect there is something wrong with the power/bias supply. But on both speakers at the same time? Unlikely...

Speakers have been in storage for several years, though. Only recently I installed new panels and did the "active bass" conversion.

Isn't the new pop related to the new active bass change?
(I agree it's unlikely for both to develop same problem at the same time.)