Is it possible to reduce the effect of "overlapping" WI-FI signals from two routers?

Question

WiFi

Problem. There are two wi-fi points. They are half a meter apart. Both are 2.4 Ghz. Through observations, it was found that when two work simultaneously, the signal from one of them deteriorates, both at a distance and in the vicinity. The connection often drops out or the speed is very slow.
Is it possible to reduce this effect if they are not moved away from each other?
I tried to change channels to 6 for one, 11 for the other - there is no effect.

Answer 1

If you have wifi n, and the band is 40MHz, then you need to spread the frequencies further than channels 6 and 11, for example, to channels 1 and 11, or switch to the 20MHz band.
Better yet, put some inSSIDer, and see what's going on on the air and choose the least loaded channels.