[backtoreality15]

Hi, I've been an owner of the AudioEngine A5s for about 6 months now. After putting a fan near my laptop on my desk (and consequentially my speakers) I've been hearing a weird interference type noise when I power the speakers off. Right when I hit the power switch, I hear and feel a loud THUMP come from the speakers. It never did this before the fan came into play and happens about 70% of the time.

What can I do to remedy this (other than moving the fan)?
And also, can this damage my speakers in the long run?

 

[backtoreality15]

Bump. No one????

 

[Armaegis]

Does it still make the thump if the fan is off?

Sounds like a minor surge that's somewhat common for a lot of amps during power on/off. Try turning the volume all the way down before hitting the power switch. It shouldn't be doing any damage unless it's a fairly loud thump.

 

[backtoreality15]

Quote:

Originally Posted by Armaegis /img/forum/go_quote.gif Does it still make the thump if the fan is off? Sounds like a minor surge that's somewhat common for a lot of amps during power on/off. Try turning the volume all the way down before hitting the power switch. It shouldn't be doing any damage unless it's a fairly loud thump.

Yes, it happens even if the fan is turned off. What is the science behind this? How does the interference/surge happen?

*EDIT* I just turned it off, after your advice of turning the amp down all the way, and it still makes the THUMP. Any suggestions? (It's fairly loud...)

 

[Punnisher]

This is normal for many amplifiers. It's caused by DC voltage going through the speakers.

Amplifiers often have DC coupling capacitors to block DC voltage and let AC through. These capacitors need to be charged fully to block DC voltage. When power is removed from the amp, the capacitors discharge and let a residual amount of DC through.

Some amps have safeguards against this, like a contact relay that engages the speakers only after the coupling caps have had enough time to charge. Though, many do not.

This is the basic idea.

 

[Armaegis]

It still seems odd that the having the fan nearby causes this. Have you tried:
- moving the fan elsewhere
- plugging it into a different outlet

 

[Punnisher]

Yeah, that's strange. Maybe it's something entirely different.

 

[dallan]

Mine thump, I usually leave them on but they have a sleep function build in and when i am in bed a while after turning off my preamp/headphone amp that feeds them, I hear the thump as they go into sleep mode. -- I have A5s for my computer speakers, yes.

 

[backtoreality15]

Quote:

Originally Posted by dallan /img/forum/go_quote.gif Mine thump, I usually leave them on but they have a sleep function build in and when i am in bed a while after turning off my preamp/headphone amp that feeds them, I hear the thump as they go into sleep mode. -- I have A5s for my computer speakers, yes.

Mine interestingly don't thump when it goes into sleep mode (just a slight crackle). I'll try to do some rigorous testing with things around my computer and see if I can pinpoint the cause...