best monitors above 300Hz


What are the best monitors in the frequency range above 300Hz? I'm using a Tact room correction system. It includes an active crossover. The manufacturer recommends placing a pair of very fast subwoofers in the corners and crossing over to the main speakers at around 300Hz.

My ideal price-range is below $2000 new or used. So far I'm considering using VMPS 626R's and bypassing the woofer (it's crossed over to the midrange ribbon below 300Hz).
jdybnis
Thanks for the pointer Ultrakaz. I'll look into the Lowthers. I'm not afraid of a little solder and glue but I don't have the equipment (or space) to do much woodworking.

You're right about it being hard to find fast subs. For the hundreds of subs on the market I've only found a handful that have the potential to produce over 300Hz.

- VMPS makes a sub that plays up to 600Hz.
- VBT/TBI makes a sub that some say mates very well with horn speakers and electrostatics and I could probably push up to 300Hz.
- Tact also makes subs specifically for what I'm planning to do.
- Talon's Roc and Thunderbird go upto 500Hz and 700Hz respectively. They claim to have the "fastest" sub available.
- D-Box's Mammouth [sic] is supposed to be very fast and goes up to 500Hz.
- RBH also has a sub that might do the trick

That's what I've found so far. Of those the TBI/VBT and VMPS are very resonably priced (both under $1500 for a pair); the D-Box and Talons are completely out of my price range ($8000ea for a Mammouth, $2700ea for a Roc, and $11000ea for a Thunderbird). The Tact subs are an expensive backup plan (over $2000 for a pair).
Re the monitors: VMPS are very impressive speakers, especially considering the price: fast, detailed, transparent.
ATC SCM 12's. ATC is well known for their accurate midrange and they are not harsh / bright like B&W can be or dark / cold like DynAudio.