Thoughts on an older REL sub?

This might help. 

https://forum.audiogon.com/discussions/rel-strata-iii-vs-rel-q201e

Note that they prefer the Strada over the designed for HT Q series? I had a Strada lll and it was decent. I now use S series which are better again. You might consider using two T series subs instead. T5x, T7x, T9x etc. Depending on room size

q201 getting pretty old

check the woofer surrounds make sure they are not disintegrating, and also the plate amp to make sure it is quiet (they go bad with aging caps etc)

older smaller rel subs are much slower than modern ones, i would consider the strata or storm series as the minimum acceptable for modern two channel applications in a good system

I agree with @noromance . I would only add that the older Rels were underpowered for large rooms. The Rel Storm lll had a 150 watt amp whereas the newer ones have much larger amps, IE 550 for the S-5. 

Thanks for the responses. @jjss49. Yes the Q201E might be a old I am able to get it in good condition.  

@highend64 REL are extremely different.

You might want to take advantage of the companies in home demonstration period. 

@m-db Thanks. In what way are they different?

Richard Edmund Lord (REL) termed his products Sub-Bass systems as they are -6dB at their rated low frequency, even today. This dramatic low frequency roll off allows for greater room placement flexibility as they do not excite the rooms standing wave bass modes.

Compared to your current subwoofer they can not provide the delicate subsonic presentation regardless of how many are used. There’s a chance you may find this to be a difference your interested in.

Look into the REL trial period offer for a better in home comparative understanding of their differences.

If you haven’t already done so, I’m an avid proponent of using the subwoofer crawl to locate a rooms bass modes to position your current subwoofer in, then recalibrate.