MadEngineer:

 

 

my $0.02 here.

i would check for sounds on your sewage and storm water pipes. town water is also a possibility. i suggest rigging up and old fashion mechanical amplifier. ie trumpet, the mechanics screw driver on the part and ear, or hose and funnel etc. if its low frequency use something very very wide.

my wild guess here is a pump station with a poorly setup pump, ie cavitation, that would put pulses up the pipes.

tweake:

my $0.02 here.

i would check for sounds on your sewage and storm water pipes. town water is also a possibility. i suggest rigging up and old fashion mechanical amplifier. ie trumpet, the mechanics screw driver on the part and ear, or hose and funnel etc. if its low frequency use something very very wide.

my wild guess here is a pump station with a poorly setup pump, ie cavitation, that would put pulses up the pipes.

garbonzai:

Thanks for the advice,

I might look at getting a mechanics stethoscope or similar and have a listen.

How about "Advance Spectrum Analyser" on your phone? Screen shots from a few minutes ago. The 43Hz appeard to be coming from my fridge in the other room as it switched off and went away, it is a barely audible hum when running . The 86Hz,172hz and 387hz are harmonics.

If the vibrations you are feeling are the magnitude you describe it may well pick them up.

Pete

doubletop:

garbonzai:

Thanks for the advice,

I might look at getting a mechanics stethoscope or similar and have a listen.

 

How about "Advance Spectrum Analyser" on your phone? Screen shots from a few minutes ago. The 43Hz appeard to be coming from my fridge in the other room as it switched off and went away, it is a barely audible hum when running . The 86Hz,172hz and 387hz are harmonics.

 

 

 

If the vibrations you are feeling are the magnitude you describe it may well pick them up.

 

Pete