You don't lack bass, you have too much treble

I usually ’go flat’ to start, then tweak above 6Khz to compensate for ears with aids.

Spouses’ ears are OK, so she informs when high hi’s are ’nuff. *G*

Bass is fine: 2 - 10" in 3way driver cabs, mids & tweets disconnected.
A single self-powered 8" in it’s own original cab.
When the Walsh get to harmonize, the upper bass/mid cones are equivalent to a 7" in surface area and make for a nice ’fill’ in the near ’back’ (Just don’t have the floor space for Everything front stage....).

If that ever becomes boring or seeming to be weak....which I can overdrive the space now....

2- 18"s. 1 - 12", and a 10" that has a mag structure as big as a 100’ spool of #12 speaker cable and weighs ’bout 30ish lbs. by itself....all of these desire a cab that I don’t have the room or the amps to do it all some form of injustice....

Oh, and there’s the 2 - 12" Utah’s with their matching expo horns that could punch through all that, even set up like a NY Ohm as they is...done for grins and a way to store them....

If the treble needs more than the pair of large Heil amts’....got another pair. ;)

Yes, Erik....absolutely crazed. *L*

But....Not Insane.👍😎

@minorl And, what level of smoothing are you using? How many speaker systems actually produce sonically accurate bass down to 18 Hz at the listening position? I'll give you a hint. It has a diameter of three mm. There is no such thing as a system that could not benefit from subwoofers if you want a realistic presentation at volumes that will not damage your hearing.

I am a fanatic when it comes to measuring systems. I have been doing it since 1995. However, it helps a bunch if there is something you can do with the measurements, like use them to guide your use of equalization and adjustment of group delays, set up of subwoofers, etc. All this can be done digitally at very high resolution. These tools are so powerful I can make a middling system sound like one 10 times as expensive. There is no other way to integrate subwoofers correctly. Every other method is wishful thinking. Can you take the edge off a bad room? No, not completely as the reflections disturb the imaging. You have to manage the room with the appropriate methods or use speakers with tightly controlled dispersion.  Measure away and get yourself a full function digital preamp.

@erik_squires Give me a break. Treating a room makes speakers sound smaller not bigger. Subwoofers can make a system sound bigger if a two way crossover is used, much bigger. 

Treating a room makes speakers sound smaller not bigger.

Not if you do it right, no. 

Subwoofers can make a system sound bigger [...]

Yes, they can.

The point I was trying to make is that what we hear is relative, and the overall balance matters.  Yes, a subwoofer increases bass.  Reducing mid-treble reflections in a room has similar effects as adding more bass, with the added bonus of often improving imaging and reducing listener fatigue. 

Dead rooms are boring.  Subwoofers are essential.

As usual many half truth by our friend:

Treating a room makes speakers sound smaller not bigger.

This is completely false except for those who had no idea what they acoustically do ...Room acoustics by the way is not only the use of passive materials on a few panels.  More active devices can be used as resonators;  and yes even materials treatment and especially active treatment with among others devices as Helmholtz resonators can make the acoustic recorded translation of any album bigger and more holographic in your room new fine tuned acoustic space ...

Subwoofers can make a system sound bigger [...]

The op is right here then mijostyn too ... 😊

I am a fanatic when it comes to measuring systems

Go only measuring gear with your other gear/tools  and room  ad infinitum till perfection ...😁 For us any measures set must be coupled to hearing/brain  experiment biological controls too ,  save inner ears measures and HTRF  tracking measures  the most important one anyway with the room geometry and size and acoustic content  ...