[Oak]

To add - Volvo speakers are colour coded, often with a coloured label on the rear

Yellow and blue stickers - I can't recall which is the better but a quick Google should confirm. EBay and breakers often sell sets too for not too much money. My issue with that was that it's often something that isn't tested before dismantling the car - at least not well enough. You don't want the hassle of fitting a whole set to then discover they're not much better or worse. I think best to source second hand speakers if you know the source or some sort of warranty they will work?