They will not interfere with each other so to speak but what will happen is the router will change its transmission speeds to match the earliest generation wireless device accessing it.So if you have a G device and an N device accessing an N router (which is backwards compatible with b/g) the N router will throttle back its transmission speeds to match the G device, you will not see N speeds unless you only have N devices accessing the router. You always want to use either channels 1 6 or 11 because they are the non overlapping channels in the 802.1x standard. This is also why you want to make sure your router is encrypted, You could have all n devices running on your end but a neighbor either knowingly or unknowingly could be accessing your router with an earlier generation device lowering your speeds.
This is CABL.com posting #337381. Tiny Link: cabl.co/mbzVN