Should Monitor 5JR+ Have Some Bass?

Yeah, obviously with a 6-1/2" midrange driver and PR, you aren't going to get much bass, but you still should get some. My set deliver very nicely with a little bit of very nice, natural-sounding bass. You might possibly have leaky cabinets. Have you done the air-tight test with pressing on the PRs to see how the midrange drivers reacts? If they are returning back to their original position less than about two seconds after you push in and hold the PR, they may need a re-seal of the cabinets' seams.

Or.....have you checked your preamp? You may have your treble turned up and/or your bass down!

Both pair I have put it out... The pair in the kitchen are such that I have to pull some bass out. Granted the room is only 10×10ish, but they easily fill the space.

Bass at 4:57
https://youtu.be/OO5Tq3uj6EQ

They should have one roll or possibly looser stuffing up behind the tweeter. I found doubling it, so it was also behind the MW too, helped for richer bass. I have two sets of 5Jr+'s and stole the stuffing out of one to add to the other.

That said 5jr+ will not have room filling bass at moderate volumes, and I think start rolling off around 70-80Hz in a regular room. The -3db at 48 seams a bit of a stretch. I think they fall off pretty quick after 50Hz, and are well down at 40Hz. Wall and "bookshelf" positioning can help bring up the bass. At low volumes I think the rolloff is less noticeable.

That is in a room regular room. Now put them in a small office or sit fairly close to them, and at a medium volume the bass is there. I am impressed and like the sound. The bass is very tight, and still rich. A sub at ~35-40Hz would only be needed if you wanted to feel more bass.

From the purists sense I am not adverse to tone controls with these. A sub may be purer, but with a little bass boost at 50Hz and below, at moderate volumes they sound like a very full speaker and dig deep. They will produce a decent 30Hz tone.

The Hafler tone control on the DH-100 and 101 is not supposed to have near as much adverse effects as others. Years ago I measured it as picking up about 50Hz and below and being pretty flat at half boost. The spec's say ±12db @20Hz. At some point I found the charts on the frequency curves for it. I think it boosts some at 20Hz, and as the boost is increased it extends the starting point to higher frequencies while not over boosting the center frequency. I have only used it between 1/4 and 1/2 boost. It smoothly picked up the bass on these, 4's, and peerless M5's when you don't have a sub, and want a little more low end bass.