source for HDF

Anyone know where I can source HDF? Here in Canada it seems I have to buy at least 60 sheets in order to acquire it.
Your best bet would be to find a dealer that specializes in supplying wood workers with furniture grade plywood and hardwood. If they don't stock the HDF they'll special order it.
There are a lot of brand names for HDF, such as Ranger Board or Medex. You'll need to just open up the Yellow Pages and call all the hardwood suppliers in your area to find one that keeps stock. Here in the states at least, most decent size towns have a supplier for 'specialty' materials like HDF.

What is your planned use?
Thanks for that insight, Vapor1. I'm in the planning stage of building a pair of JBL 4345s. However with 2206s for mid bass and 2441/2390 for horns instead. Bass drivers will be the original 2245s as will the 2405 tweeters. I'll also increase cabinet volume a bit to about 11cu.ft..1/2" HDF sandwiched between 2 layers of 1/2" baltic birch with a layer of 1/16" thick modified roofing felt between innermost 2 layers. Oak veneer. They'll weigh a good 200 or so lbs. each without drivers. Drivers themselves for each side weigh 100lbs. A pair of Behringer DCX 2496s to cross them over and 3 Acoustat TNT 200s and 1 TNT 120 rebuilt by Roy Esposito of Sounds Like New. I have everything but the cabs.