How do you point, this antenna in two different direction, buffalo and toronto. I live in burlington.
Do they work in both direction, you can not combined two antenna in one cable

They work in 2 directions (frontwards and backwards) if you remove the reflector. Not sure if that "fix" will work in your location.. .

DOH! The 8-bay Digiwave is actually two 4-bays on a hinge.

Google, simply point one side at the CN tower and the other towards Buffalo.. .

Well you do not have to google it , yo can use yahoo, lol.

I tried a lot, eventhough one point cn tower, one point to buffalo. Only channels i got are CBC, CHCH, suntv, cts.

Someone told me you can get alleast 18 to 20 good channels. I believe digiwave multidirectional antenna is crap !!

Please help if you know for something

You should get 23 on your front porch. It's OK to combine two signals. Aim your antenna down the lake between the tower and Buffalo. Don't remove your reflectors. Check all connections.

The 8 bay's advantage over a 4 bay, is most prevelent when the two sections are at angles between 60 and 300 degrees from each other.  I would aim the one antenna North East, and the other one, South.  The North East one will pick up Toronto, the South facing will pick up Hamilton, Buffalo, etc.  Make sure you can get at the antennas, to fine tune their directions.  making sure that you maintain a close to 90 degree angle.

You can also use an amplifier that takes multiple inputs, these contain circuits that will fliter the signal so that the strongest signal gets through, and the slightly weaker one gets filtered out.  I believe that some of the Channel Master amplifiers have this.

The other issue, the higher the antenna, and the more open the antenna is to the outside the better.  An antenna in a basement room needs to be aimed exactly at the signal source and needs to be fairly close to the source.  An antenna that is outside, 1m off the ground will pick up much more, one that is 3m or more off the ground, will pick up much more.  Some people on high floors of apartment buildings with the balcony facing the right way, can get incredibly distant signals, off the balcony. 

The eight bay is intended to be pointed in one direction. Otherwise it would be called a dual four-bay pointable.

But yeah, you can point in two directions, and the two sections should be as close to 90 degrees from one another as possible. As stated above.

I've never seen an amp that filters signals so only the strong ones get through. Brand and model, please.

The higher the antenna the better is true unless you're really far away, and then it's hard to predict where the signal will be best. But then you'd be trying hard to get one or two stations, I guess.