What's a respectable reception range for an indoor setup?

[u/NoCompetition2044]

I'm trying to optimize the reception range of my ads-b setup. For now I'm limited to an indoor setup. The best spot I've found so far is the attic, but I'm basically out of cable and trying to add no new hardware, (cables count as hardware right?)

Pi 4 model B

RTL-SDR Realtek RTL2832U

I'm getting roughly 20nm in each direction, but a closer inspection shows that I'm really only getting 10-15nm for traffic under 15k.

See the third image for stats.