I recently picked up a 2017 ATB, and while playing around with the audio, I noticed that the subwoofer may not be working. It is unclear where the subwoofer is located. Range Rover brochure shows it in the rear of the car while part sites show the box as under the front seat? Can anyone give me a definitive answer? What is a good way to definitively determine whether the subwoofer is operating? And if not where is the best place to start the investigation?

What sound system do you have? 1700 Signature?

For testing it, depending on how you get your music, you can download test tones. I use Apple music & there are a range of frequencies available so you can just keep going lower until it should only really be using the sub.

Yes it is the signature.

I tried some of the bass tracks on Apple Music. I would turn the Bass setting all the way down and the subwoofer setting all the way up. It was still hard to tell whether the bass was coming from the door woofers or the subwoofer. I believe they are not that much different in size? Likely able to hit similar low frequencies.

So I tried the same Bass tracks in my LR4 today, and I think the subwoofer presence was quite obvious. I am even more strongly suspecting the one in the RR is not working. Remaining questions are where is it located, and are there any common reasons for it to stop working?

Testing for reproduction lot depends on the quality of the of recording and test tones recorded on a CD the only way to go really they are much better quality reproduction than MP3 and almost @ FLAC levels of minimal digitisation loss.

But music is emotive and feeling it is as important as hearing it so if I want to test a car audio system for "feel" I use a CD of Sade's Smooth Operator at high levels of volume, bass & sub bass, that'll help souce any rattles in your trim, pens or coins in the trim etc. and give your speakers a good workout. But be warned, if it's not up to snuff it'll shake it to bits.

If you pass that without buzzing or distortion then you've got a good system. Fuji White / Jet 2012 4.4 TDV8 Westminster

If you’re still unsure, try Welcome To The Machine from Wish You Were Here on the Meridian reference system.

Volume 20 or so & you should be left in no doubt. 2016 SDV8 AB

I appreciate the track suggestions, but I was hoping for a definitive answer for subwoofer location. The brochure has it in the back of the car:
https://drive.google.com/file/d/13W095n7C2...sp=sharing

But the part shops have it listed under the seat:
https://drive.google.com/file/d/1GDc8d0VQP...share_link

Around the facelift the subwoofer moved from under the seat to next to the spare wheel.
When I changed my speakers on my 2020 RR. It was next to the spare wheel. The subwoofer is also of a different construction. SDV8 AB MY 2020
MINI Cooper S Cabrio
Kit: Jaguar XK140 (in progress - the website is link to build)

Ah, that's a good tip. I did look at the brochures for the 2016 and 2018 model and they do show the difference. Looks like mine should be in the back. A quick look at the spare wheel did not present a subwoofer. I'll have to look closer.