Watch the Bridge Mutes & Tone online guitar lesson by Andrew Ford from Motown Bass Survival Guide
Some of the gear considerations when trying to get that Motown sound include one thing I didn't use on this video, a Fender Precision Bass. I purposely did this to show you that it's still possible to get that sound, even if you do not own a "P Bass" even though this was Jameson's instrument of choice.
Other crucial elements that will help you get that sound are having some sort of muting device, whether that be foam in the tailpiece, as was standard on the old fender instruments, or using some other custom or homemade foam muting device. These devices, in general, are placed under the strings and close to the bridge. It may take some experimenting to achieve your desired sound depending on the thickness of the foam and how much pressure it is putting on the strings. Different types of foam can be used, I have even used a sock before. You can also use your fingers on either hand in different combinations as muting devices. Flatwound strings are great for this Motown sound, they're not versatile, but they are great at what they do. Rolling off the treble and possible setting up your bass with higher action can also help you create that sound.