I had some free time today and I went on a mission to find out more about these types of pedals. Like, what else might be out there. I did some research and this is what I came up with…
Here’s an article on TalkBass that was the foundation of most of my research… Cross-Over (Crossover or Splitter) Pedals
They also get called Crossover Mix Pedals, FX loop pedals, or just loop pedals. Which makes it more confusing because they’re talking about FX loops and not Looper loops. Just wanted to point this out so anyone reading this in the future doesn’t get confused by the terms.
I think part of the reason they’re so hard to find is there’s no consistency in what they’re called. Also, they’re considered a specialized pedal without a big market.
$85 Byte Heaven Single Cross
This was the most affordable thing I could find. However, it doesn’t give full loop. You’d still need a device to bring the signals back together.
$153 Byte Heaven Sugar Britches
This pedal has a good reputation on TalkBass and seems to do what you’ve described. However, it’s still the size of a full size pedal and I wouldn’t call it inexpensive.
$179 Damnation Audio Loop Blender
$279 JohnK Cross-Mix (These are built per order.)
$200 KMA Tyler -The Frequency Splitter
$235 Iron Ether Divaricator
$320 Bored Brain Transmutron
$??? Brimstone Audio Ouroboros (seem to be made per order)
$??? VFE Klein Bottle (discontinued but interesting from a research perspective)
If none of these give the proper combination of loops and filters, SaturnWorks Pedals will build what you want and they have a good reputation on TalkBass.
As an alternative…
One Boss LS-2 Line Selector ($70, used) and Two Boss GEB-7 EQ pedals (at $70 each, used). If you take your time you can probably get each of these for $50 a pedal. This isn’t a very space friendly though.
Lastly, I don’t know how it works, but the Helix/HX Stomp allow you to do this. As does the Boss GT-10b.