@Oyster150
Here's a pic showing a modified lowpass for your existing Nelson Pass network.
What it does is adds another smaller inductor ( 0.68mH ) to the lowpass section and re-uses your big 22uF caps.
FYI, Just about all of JBL's newer woofers ( for the last 30 years ) have a "rising response" ( typically ) dictating the use of a 3-pole low-pass to flatten them out.
Green trace = 2216nd ( on the modified Low-Pass )
Red trace = 2235H ( on the Nelson Pass Low-Pass )
The purpose of this exercise is to get the lowpass roll-off near crossover ( for the 2216nd ) to match the intended LP roll-off of the 2235H ( as produced by the Nelson Pass network ).
One can see my mod produces a near perfect match ( between 600hz to 1K ) with the small modification ( to deal with the rising response of the 2216nd ).
Ignore the differences below 300hz >> they are attributable to the impedance files I used and give a false impression of the bass output.
Listen to this modified lowpass for at least a week to see if the balance between bass and mids is more to your liking ( or not ).
FYI, by not modifying the Nelson Pass low-pass ( and simply lashing up a 2216nd onto it ), the following pic shows the resulting lazy low-pass.
Green trace = 2216nd ( on the un-modified Nelson Pass Low-Pass )
Purple trace = 2216nd ( on the modified Nelson Pass Low-Pass )
2216nd and 2420 just melt into each other and basically can't tell the crossover region, it's that good.
That "lazy" ( @ 6db/octave ) roll-off that you are currently listening to, might be the reason for the "seamless" transition from Woofer to Horn that you've mentioned.
This is something you'll need to listen for ( after the mods are made ) to see if this transition suffers ( what with the steeper x-over slope produced by the Pass network ).
PS; You may need to eventually add another coil ( inline with your existing 2.2 mH coil ) to get that first coil's value closer to what RobH3606 did ( but I wouldn't do that quite yet until this exercise is completed ).
)
