Sub-woofer to go with WATT3/Puppy2

Question1: What sub-woofer would be recommended for the above speakers for use in the following systems: - Audio Research LS5mk3 / LS16 pre - Krell FPB200 amp The speakers are just too dry in the bass and the bottom octave is not fully there. I want to avoid buying WA own sub (the WHOW). Budget max $4000. I consider building it since I have good skills of woodwork and electronics. Question2: what would the recommended frequency be (and x-over order), if I don't cut the input to the WATT/Puppy? Many thanks
You want better bass. Then go directly ARC 600s or Atmos-phere MA II mk IIs. Don't add a subwoffer. Even the best always muddy the watters. Put that $4K into tube better amps that will improve you overall sound. You're chasing the wrong horse. Maybe VAC 750 signatures amps would provide a nice combination for you.
I have had very good success with REL products. I particularly like the fact that the subwoofer is run directly from the power amp without being inserted between the amp and main speaker. Hence, the main speaker path is not degraded. A good subwoofer will add the final octave to the Wilsons, but I'm not sure if the dryness would disappear. Gerrym5 may be on to something with the above recommendation, however, I hesitate to use amps as tone controls. A well setup subwoofer will actually improve midrange clarity, not muddy it up. The key is to smoothly excite the room's standing waves.
get a pair of vmps larger subs, a marchand *deluxe* 24db/octave x-over, & a pair of hi-power used amps, like the adcom 555's, rotels, parasounds, mondials, brystons, etc. even if the subs-n-crossover are bought new, ya won't spend over $3k, let alone $4k. the marchand x-over lets you experiment w/(inexpensive) plug-in x-over frequency modules, so ewe can get it right for you, & it's transparent enuff so it *won't* muck-up the sound of yer monitors. it'll actually help, as they won't have to work below whatever frequency they're x'd over at...