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?
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. 
You by chance don't have a speaker out of phase?

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?