Why I'm not adding a sub to my 2-way monitors for music

The averaged results looking the best

@russ69

They always do, but we take them to avoid optimizing for a 1mm wide cube where our nose might be if it were in a vise. I’m not being deceptive, I’m being thorough. This is considered good practice.

They may sound good but I’m guessing not even in the same league as bigger full range speakers

Au contraire, mon ami!

Audiophiles who do this do one of two things.  They buy a sub and set it to have as low a cut off frequency as possible, which is a HUGE waste, or try to blend them in without high passing the mains.  In neither case the results are mediocre to non existent.

To blend a speaker, of any size, with a subwoofer requires the same careful planning and forethought.

I adjusted my modest Paradigm subwoofer by ear. Sounds great. Adds what I missed with my Nola Boxers. Nothing more.

Au contraire, mon ami!

Maybe I shouldn't make blanket statements without knowing more. 

Audiophiles who do this do one of two things. They buy a sub and set it to have as low a cut off frequency as possible, which is a HUGE waste, or try to blend them in without high passing the mains. In neither case the results are mediocre to non existent.

Your comment should be clarified to say that this applies to bandwidth limited monitors. I have speakers with folded horn bass drivers. This bass is some of the best that can be had. It would be foolish to high pass LaScalas. So I do just what you advocate against, bring the subs in very low. And it works fabulously.

Not a one size fits all solution, neither is yours.

BTW, I think you meant “either” , not “neither”.

I’ve been fighting with room acoustics and a REL T9x for over a month. I was at the point of selling it until I went completely against the set up recommendations and moved it out of the corner, raised it onto a 1” granite slab and decoupled it with Herbies grungebuster pads under the feet. Now everything clicked into place, bass grip and definition, soundstage are spectacular. best of all, the relentless room resonance is gone. I don’t like the aesthetics of having treatments all over my apartment. If I ever get a dedicated listening room I’d be all for a different approach but for what I have to work with now, a sub is a phenomenal acquisition. I’m sure others are in the same situation.