I am trying to identify the source of a low frequency "booming noise" related to road speed. The bushes are in good condition and so are the tires and brakes. I don't know if this is normal for this car but suspect not. It isn't too loud but more of an irritation than anything. Is this a normal road noise or any suggestions as to what it might be ?

Not that I know but does it happen all the time or only under certain operating conditions?

Good question - yes its there all of the time the car is moving but becomes less obvious at higher speeds - I assume its just getting drowned out. Most noticeable at about 30-50mph. My gut tells me it is tire noise or even some kind of resonance...…
Steve

I wouldn't call it booming, but my car can be distressingly noisy on certain rough-chip seal roads. Of course this goes away on other surfaces.

It's unlikely we have the same tyres (mine are Bridgestone 19").

be sure to visually check the drive shaft donuts .

Some possibilities: Tires, wheel bearings (is it more pronounced when turning?) drive shaft bearing.

Hard to diagnosis, if its a problem it will get worse and let you know the source.