Higher speeds but more interference

[AusQB]

I have a Netgear WNR2000v3 router. I typically keep it on channel 11 as there are two other networks on channel 1. On channel 11, I get around 3-4 Mbps. If I go to channel 6, I get about 10 Mbps. If I set it to auto, which currently puts it at channel 2 (right next to the other two networks), I get around 20 Mbps. However, I seem to notice a few glitches, usually very brief lag spikes, which I think is attributed to higher interference levels. I just can't tell if it's just in my head.

So basically, the closer the network is to the others, the higher the speeds (according to speedtest.net using local servers) but possibly with more interference. Can anyone shed some light on this matter, particularly what causes this and which is the better option.

 

[inzone]

Switching channels is one way to get better speeds and using different bands is another. If you have a dual band router then when you get to the lower channels try the other band frequency. There are things that cause interference that you wouldn't think do but end up causing it. A microwave is one of the biggest causes , cell phones , kitchen appliences like mixers and blenders. If you live in an apartment complex or a densely populated neighborhood you can get a lot of interference.