Does You Subwoofer Settings ??

Yes the high pitch Kool and Gang Song I have to turn down for my ears..LOL...My Sub is approx 24 inches off wall and corner...See I do not understand all the language of Subwoofer and have to go by what others say and try and adjust .I am a big car guy and train and slot car person and can not read and understand ..So everything I do is by sound ...I contacted a Audio repair person and he gave me the number of person who may come out and help me..But that will not be before Fall..

So sls883 are you a sportster person ? 

You are getting standing waves if it's boomy, need to find what frequency is causing it, then change it.

Find a song that starts the boom, walk around the room to see if there are places where it doesn't boom. If it's a large part of the room, move your sub, so your listing position sounds good. 

If it is in the whole room, adjust the PEQ, always go down if you can, trying not to boost anything, just cut. 

If it's still an issue, do both, move the sub, and adjust PEQ. Might also need to adjust the XO point, as it could be interaction between the sub and mains. 

Many years ago, I bought my first Harley. As you guessed, an 883. Then a 1200 Sportster. Then a Deuce. I had custom tins and wheels on it. It was sweet, but not comfortable on long rides. Then a Road King. And finally, a Road King Custom. It was a sweet bike and I could ride it all day. But, I lived in Nebraska and the riding wasn’t great. All my biker friends were busy with kids and so was I, so I sold it.

No bikes now, but I have a 52 Chevy pickup and a 62 Chevy pickup.

My Sub is approx 24 inches off wall and corner

This is very likely not the best spot for the sub and probably a big part of your issue.  As I mentioned earlier, do the sub crawl method to find the spot(s) where it’ll likely sound much better and very possibly mitigate the problem. 

I'm also 73 and i think I've become a bass junkie, or should I say truly full range music listening addiction I have tower speakers with built-in powered subs along with two SVS Ultra 13 subs with the upgraded plate amps  I listen to everything from Frank Sinatra to Odesza  Typically I have my subs crossed over at 38 hz and adjust the gain to eliminate any boomyness  Almost all music sounds coherent and not overbearing, no matter the music  Hey my brother had a Harley Sportster and would let me ride it once in a while I reciprocated by letting him drive (hard decision) my 1972 BMW 2002ti