Assuming you have 8 ft ceilings with no other openings into other rooms, your room is about 4,300 cubic ft which is a lot of space for those speakers to fill. It seems like what you're experiencing is a lack of bass & mid-bass, especially when you increase the volume to fill that room with sound for the size of the woofers on those speakers which are handling both bass & mids.
To start:
Check in your AVR that the speakers are not set to "small" in the menu. Per a quick search, setting speakers to "small" crosses them over at 90hz, which would definitely help explain part of the issue you're having.
Here's what I'm referring to (
https://www.crutchfield.com/S-lT6DTjk2EjN/p_022HTR5450/Yamaha-HTR-5450.html):
Bass Management: The channels set to SMALL are filtered with a 90Hz high-pass crossover. The bass from the SMALL channels is directed to the front speakers (left and right) and/or the subwoofer preamp output according to the "Bass Out" setting. The available settings for each channel are as follows:
- Center Speaker Settings: LARGE, SMALL, and NONE
- Main (front) Speaker Settings: LARGE and SMALL
- Rear Speaker Settings: LARGE, SMALL, and NONE
- Bass Out: You may select SWFR (subwoofer), MAIN or BOTH
- D.D. LFE: You can adjust the output level of the LFE channel from -20 to 0 dB in 1 dB steps
- DTS LFE: You can adjust the output level of the LFE channel from -10 to +10 dB in 1 dB steps
Based on the info I quoted:
Set the
main (front) speaker settings to Large.
Set the
bass output to Main.
If the above makes no change, something else you can try for "free" (so long as you have some more speakers wire) is see if you can run both A and B channels at the same time on your AVR. If so, you might want to try bi-wiring the speakers with the A channel for the top, and the B channel for the bottom (and take out of the binding post links on the speakers when you do this). See if that makes any significant change. Again, only try this if you can run both A + B at the same time.
Beyond the "free" stuff to try, I'll echo what the others have already suggested, and it seems like you would benefit from at least 1 subwoofer (preferably 2 -
and do not cheap out on a sub or subs), a measuring microphone like a UMIK-1, and then start with some measurements. A UMIK-1 (or similar) with REW will provide more context with a frequency response graph to see what's happening with your mids / bass response specifically.
There is a caveat to all of this, which unfortunately you may not know until you get there, and that is that the speakers may not output the mids you want (at the volume you want) because the JBL 530 woofer is still too small for the room you have
even with a sub. If that ends up being the case, the solution is probably going to be floor standing speakers. Unfortunately, you won't know that until you try with a sub first.
I do not have experience with SVS subs, but I did strongly consider them when I was shopping around a few years ago. I went with Rythmik based on reviews, but the only wrong choice is buying a cheap sub that does not deliver what you want, can't extend low, etc.
Depending on how loud you like to listen to music, a single 12" sub might not cut it fully for your needs, but anything will be better than no sub. The good news is that as long as you don't blow up an SVS you should have no problem reselling it to get something larger. I imagine you might settle on 15" subs for the size of your listening space. That said, 2 separate 10" SVS subs will be better than a single 12" or 15" due to the physics of low frequencies in rooms.
There's a good list of subwoofer comparisons on this forum as well here:
I've created a *slightly large* subwoofer comparison spreadsheet. :D Info: -==Link to my Subwoofer Comparison spreadsheet ==- https://bit.ly/SubwooferComparison
www.audiosciencereview.com
Towards the end of the above linked post, is a database of subwoofers and their measurements here:
Sheet1 CTA-2010 results scaled to 1M peak equivalent (updated 8/23) NM = not measured, NA = no measureable output,avg. ,avg. MODEL,Driver,Loading,80 Hz,40-63 Hz,63 Hz,50 Hz,40 Hz,20-31.5 Hz,31.5 Hz,25 Hz`,20 Hz,16 Hz Andover Audio SpinSub,(2) 6.5",ported,109.6,107.1,110.3,105.5,104.3,92.5,98.6,91.2
docs.google.com
There is also this additional list of subwoofer tests with room sizes, with an excel file you can download at the end of the article:
This article outlines our test procedure in determining a subwoofers room size recommendation based on its max CEA SPL output while making room size and subwoofer distance assumptions.
www.audioholics.com
To sum it up:
Try the "free" stuff first (if you haven't already)
Invest in a UMIK-1 (or similar) to get measurements
Invest in at least 1 sub, and an SVS SB 1000 would be better than nothing (2 separate subs are better due to physics).
Hope this helps!