What JL Subs to pair with Harbeth SHL-5 Speakers?

What ever you do use a real crossover, there is no substitute when using subs.

I would also look at JL's new eSubs. Budget-wise seems like a better match to the Harbeths and the e subs offer the full high-pass/low-pass capability.

With two superb subs crossed over at around 80 Hz, you might want to consider the Monitor 30.1, which should give you better midrange and treble than the SHL-5.

Another option is to go with smaller subs and use 4 of them. That apparently is the road to getting the best room integration, or so I'm told.

Bob reynalds,
I use the high level inputs on my REL Strata iii, so the cable is hooked up to the speaker out terminals on the amp.I see where you heading, and you present an interesting consideration. However for my setup it isn't applicable. Thanks

Bob reynolds,
I enjoyed the conversation.