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

Room is 27x16x8, and considering SHL-5 speakers with a pair of JL Subs instead of going with the 40.1 Harbeth. Trying to decide betwen F-112 and F-113. Leaning towards a pair of Fathom 113 Subs with the SHL5. Any comments.
I have a single F113 in my 19 by 20 ht room and it is more than enough and never feels pinpointed bass wise

If you can go larger, do
I run. reL b2 and it's awesome. Compact 7es3's
Your room seems to be plenty large enough for the 40.1. As far as total cost and space needs, wouldn't the 40.1 without the subs be a better choice. I use a REL Strata iii sub with my 30.1's, but even then I find integrating the two can be a challenge to get the sub set for every type of music.
Valinar makes a good point that in a your relatively large room, perhaps the 40.1 is the better choice. But if you stick with SLH-5, a pair of JL F113 should be plenty -- provided you split the signal and relieve the SLH-5 of the bass work. If you have spoken to JL Audio, you know they strongly recommend crossing over to relieve the mains of the work that is the sub's specialty. True, integrating subs can be a challenge, but it is doable; and when done right, its terrific. Also, integration is far less difficult when using a cross-over, rather than having the mains rull full range and overlapping the sub in the mid-bass.
I find integrating the two can be a challenge to get the sub set for every type of music.
Why is this? Is it just a personal preference to boost or cut the bass for different types of music?

If you had level controls for the tweeter and midrange drivers, would you adjust them for different types of music?
Bob reynolds,
Good question. No I would not adjust "level controls for the tweeter and midrange drivers". The crossover is designed for the speaker and best left alone. The speaker has its specific limitations as far as bass extension. I know this is elementary but obviously the subwoofer is only to complement the existing speaker as it is designed. As far as me finding it a challenge to set the sub to accomodate every type of music, I would use a quick example of a couple of different recordings. Beck's new release "Morning Phase" has in my estimation been produced rather bass heavy. That said, I really like the album.There are other albums somewhat similar, such as Robert Plant and Allison Kraus' "Raising Sand". To go from "Morning Phase" to Ralph Vaughn Williams "Fantasia on a Theme by Thomas Tallis", a delightful recording by Academy of St. Martin in the Fields orchestra conducted by Sir Neville Marriner,a bit more of a lower bass boost would be pleasing.
There are times I get sucked into a analytical listening mindset instead of just relaxing and enjoying the music. The Harbeth 40.1 would most probably eliminate the need for a sub. Hence any need to integrate a sub is eliminated as well. Thanks for the question Bob.
What ever you do use a real crossover, there is no substitute when using subs.
You say that the crossover of the main speaker is best left alone and you wouldn't adjust levels of the tweeter or midrange driver even if you could. But, what if you used a real crossover (high-pass filter and low pass filter) to integrate the subwoofer? Would you still feel the need to adjust the bass level?

It seems you're implying that you'd be OK with the fluctuations in bass levels with differing music when reproduced with a close to full range speaker like the Harbeth 40.1 since it's crossovers are designed for the speaker.

I'm suggesting that using a true crossover to integrate the sub may give you the same acceptance of bass variability, but with the advantages provided by a sub. What do you think?
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
I use two e112 subs in my system using the internal high pass between my pre and amp. I also tried the same setup without the crossover and passing under them main for a more common setup. There is no substitute for the crossover. Without it they sounded slow/off pace but with it turned on it is seem less (enough for all but the extremely picky). But I wish the e112 has room correction, or they could add the crossover to the f112.
I was, maybe not so subtly, picking at the speaker level connection endorsed by REL.
Bob reynolds,
I enjoyed the conversation.