Posted: May 20, 2015 2:18 pm
by electricwhiteboy
Bass amp does the trick, and a proper synth you can dial down far enough. Some equipment is deliberately locked to cut these frequencies either prevent damage to the speakers, or you spooking out your neighbours. Church organs have massive pipes for generating that kind of rumble if you pull the right stops out.

Lots of things in an urban environment might kick out infrasound, diesel engines mainly. One of the "haunted" locations in Edinburgh has a busy bus stop directly above the vaulted cellar. It's also surrounded by nightclubs and rock bars with live music. There is also a fairly major power line goes that through there which might add a bit of EMF to the cocktail.