wum, wum, wum...wah, wah, wah
Interesting that you would post this when you did. Earlier today I posted in another forum area (engine/transmission) about a low speed noise I'm getting in our 2014 Escape Titanium. I described it as wah, wah, wah, but a little imagination I could hear it as wum, wum, wum.
We just got this vehicle, and it was present even when we test drove it before buying. It had some pretty cheap Chinese tires on it, so I thought that might be the source. Now it has brand new, premium all-season radials properly inflated, and we still get the noise. The twist on my situation, and I would be curious if you have the same, is that if the car is just rolling at low speed without any accelerator pedal providing power to the vehicle...or if it's just rolling in Neutral, there is no noise. Mine only occurs if the engine/transmission/drive shaft is powering the wheels. I consider myself a pretty advanced DIY mechanic, and this doesn't match to anything I've ever dealt with before. Not indicative of wheel bearing, bad half-shaft joint, brake rotor condition or anything else.