I find the lab 2 can struggle with certain types of music, sometimes it seems a little boomy which I feel is because it struggles to cope with all thats going on like say indie music as an example but then on say dance music it sounds awesome!

In answer to your question, once you have a lab2, there is no going back! despite this "slowness" it really is a must have addition and I for one would not go without.

For music one needs a subwoofer that is accurate and precise. It is felt by many that the BL2 is just to 'boomy' to provide that accurate sound experience.

There is only one 'driver' cone on the bl2 the other 'speakers' in the unit are 'passive radiators' that work in symapthy with the main driver so you might be able to imagine that this adds a lack of distinct bass sounds.

How many time are we going to reccommend the PV1 for setup's like these 😕 Here goes anyway,

Try the Bowers & Wilkins PV1! It's fast (accurate), perfect for music and half the price of a BL2. The BL2 with its passive radiators, when listening to music, spoil the lower register - to my ears. I disliked what the BL2 did to my BL4000's

You get a powerlink to coaxial cable and connect the sub to the BS4 powerlink (if you have the BL3's daisy chained 🙂)

Then all you have to do is set the bass setting to it's lowest on the BS4, and tweak the crossover and volume settings on the PV1, voila, BL2 beater. 

I agree with Moxxey, get a pair of Beolab 9's. If you want to keep the Beolab 8000's and add a sub than I would choose the Bowers & Wilkins PV1 as suggested by the rest. Amazing sub, really 🤒