Weird problem noticed today...

This has never happened before but in my Bluesound Node 2i today there is - I can it descrbe is as - bass slap or pop, I think just coming from the left Maggie. I pretty much only play loud. My subs are right behind the Maggie (16" or so) and it's definitely coming from the Maggie. Now the DAC on the Bluesound has a lot more boomy bass than the CD player DAC - Yamaha Aventage BD-A1060. So I am thinks my it's signal-related but perhaps it's the Maggies only they are not being driven hard in those frequencies enough to make that horrible sound. BluOs just did an update that is only major change to system today. I probably hadn't played music on a couple weeks and BluOs asked me to do update then I noticed problem - could be coincidental though could this be an amp or preamp issue?
Sounds like they have been driven so hard the diaphragm stretched to the point where its contacting the stator(s). First test you should have done, always do, with something like this is swap channels to narrow it down. Least likely but easiest is swap channel inputs into the amp. Also unlikely and slightly less easy is swap speaker cable ends on the amp. If you have the extra few inches that will be needed for that. When the left speaker now driven by the left channel still pops then you know for sure I was right, er I mean its the left speaker that's bad.

Magnepans don't have stators.  Stators are part of an electrostatic speaker.  Maggies are planar magnetic.
I was a Magnepan dealer for many years. Without really seeing/hearing the problem, my best guess is that you’re simply over-driving the panel.

This is known as "panel slap". Especially in the bass region. The panel can only move so far. If it’s over driven it will cause this to happen.

You will really need to isolate the problem. Could be with the electronics. Troubleshooting it all the way through is best. Isolate each piece and follow the clues...

Also, the BluOS has a tone control setting. Make sure it is "off" or that the level is at zero. Could be you're pushing extra bass, (or treble) through the Node 2i.

Yes BluOS tone control is off. Been procrastinating as I am afraid of result (though they are still under warranty). First I will swap left to right and see.

Weird I can't seem to hear it on CD. 
So the ribbon "slapping" isn't fatal? I was not playing it any louder than I ever do. 
What model of Magnepans do you have?

You might want to do a reboot/reset on the Node2i, just to make sure it didn't get "stuck" when updated.  I just updated mine and didn't notice any anomalies. 
Agree with mofi's suggestion of doing a hard reboot.  Two updates back I had some audio anamolies as well as Spotify disappearing from the main menu.  If the reboot doesn't work you can do a fectory reset but know that it wipes out all data stored......everything.  It will be a complete start over process.  I had to do factory reset to clear things up but it's been flawless since.  
When you asked "if the ribbon "slapping" is fatal"?  I assumed you had a separate ribbon tweeter, (like a 3.6/3.7/20.7) which would be weird if that was slapping.

The 1.7i is a quasi ribbon panel, not a full separate driver, so no, Maggies will slap if over driven.  You really should try to avoid that, but it's not fatal.
Well that's the weird part. We'll see gotta do that testing. As it wasn't being driven any more than it has for 2yrs and suddenly slapping. 
Also weird is you said that it doesn't do it with CD, right?  Do you have any other source to try?  I'm sure the Node2i and the CD don't have the exact same output voltage, but they should be close.

If you have a sound pressure meter, maybe measure the output with both sources to make sure they are matched.  You might just be over driving the speaker with the Node2i as the source or maybe with the update, they somehow increased the output a little?

Logic tells us, (thanks Spock) that if the only source that is causing this to happen is the Node2i, the issue's gotta be with that source...
I would also add that as with the poster above the recent Node2i update resulted in no negative consequences at this end.
I'll keep all that mind when I get 'round to testing. I think I noticed, after the update, a reverby sound esp to vocals as well. I am worried that - at lower volumes I heard the slap as well but that could be worry playing tricks. Will let all know when I know more.

Cheers for all help so far. 
well they sounded perfectly in phase before this happened so I seriously doubt that. and I never heard, in 50 yrs being a budget audiophile of a out-of-phase speaker having a bass slap.
I never heard, in 50 yrs being a budget audiophile of a out-of-phase speaker having a bass slap.

Correct.  Usually an out-of-phase speaker will have less bass, not more.
Well...inconclusive. It was definitely worse on the left. So I physically switched the speakers. Now it's mostly on the right but some can still be heard on the left. Its not constant. And, as I said, the Bluesound has boomier, deeper bass than the disk player (although disk player sounds great) and it is NOT noticeable when playing same song through CD at same volume on preamp (LOUD. But, again, different sounding DACs/marginally different outputs).

So I hav done 3000 songs saved on the BluOS app. Did someone say I would lose all that if I do a reset?

I want to do my best to understand what's going on and which component might be the culprit before contacting any tech support. 

Other thoughts?

You can do a "reboot" and not lose anything.  Just unplug it for a few minutes or you can reboot it from the BluOS app.


A Factory reset will lose all the info.  If you saved the 3000 songs on Tidal or Spotify or Qobuz, or etc.  They will all still be there.  Where did you save the songs?
Well it's resolved but it's weirder. Just did reset on the Bluesound and it's gone! I can't fathom why. 

Thanks for all (especially the reset) help.