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
If you can go larger, do
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.
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.
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.
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.