Use the 4Fe with the SB as a woofer....
Interestingly, I already have the 3FE22....
But I don't feel like I'm missing much with SB20FRCP30 at all.
The midrange is amazing and the high sensitivity is easily felt when you turn up the volume.
@Nissep, if have space for a bigger speaker, totally recommend to give it a try

I have one of these kits on the way and hope it might improve things. Have a look here:I actually like the original sound of the 4Fe32. Except for the 8kHz peak. I have mine in a Fostex BLH case. So I don't think it is placebo... Been meaning to put a 8kHz notch filter... But alas... Life gets in the way...
https://www.diyaudio.com/community/threads/full-range-eq.399413/post-7353325
Ohh i have huge speakers too, but the objective/goal with this one was to explore the new 4fe42 and it was shortage of building material in the garage that lead me to the final design.Interestingly, I already have the 3FE22....
But I don't feel like I'm missing much with SB20FRCP30 at all.
The midrange is amazing and the high sensitivity is easily felt when you turn up the volume.
@Nissep, if have space for a bigger speaker, totally recommend to give it a try
View attachment 1177225
I have previously done a system for a lounge at work using 4fe32 and dual 8" ppsl bass support boxes that was impressive for its size.
That time i used felt pads glued to the cone to tame the breakup, and the box was a small/short heavy damped transmission line that provided a little support around 100Hz.
I have the SB as well and have stuck it in a Sony TL cabinet. The mids are nice but IMHO not as detailed as the 3Fe22. There is actually a decent treble but not as airy... However I felt that the SB has one of the most articulate bass around. Both very nimble and deep. So I am using mine as part of an interchangeable module thing. Add a crossover externally and a 3FE22/ribbon tweeter/4Fe32 as well as just use by itself. That way I can have fun swapping things around. Sort of like having a Harem of sorts...Interestingly, I already have the 3FE22....
But I don't feel like I'm missing much with SB20FRCP30 at all.
The midrange is amazing and the high sensitivity is easily felt when you turn up the volume.
@Nissep, if have space for a bigger speaker, totally recommend to give it a try
View attachment 1177225
I bought a crossover from AliExpress that supposedly a low pass at 300Hz at 8ohm. But I haven't installed and measured yet. I plan to cross mine at around 300-400Hz. basically a WAW/FAST design.
You can also consider crossing yours to a tweeter at about 5-10kHz for some air ..
Or maybe just a high sensitivity rear firing/top tweeter. To add in air...
You can also consider crossing yours to a tweeter at about 5-10kHz for some air ..
Or maybe just a high sensitivity rear firing/top tweeter. To add in air...