Dakotadawg, I have tried several different howlers, and have finally settled on a couple. I have asthma and have a hard time blowing certain calls. It seemed like the ones I liked the sound of, I couldn't blow worth a hill of beans. The ones I could blow easy, I didn't like the sound of.
One day I spotted a WoodsWise Howler. I bought it, and found it was easy to blow, but I didn't like the sound of it, or the volume. Well I attached a megaphone to it (plastic transmission funnel from an auto parts store) and it increased the volume, but I still didn't like the tone of it. I then made my own reeds. I tried several different kinds of plastic I had laying around the house (milk jugs, coffee can lids, etc.). I finally found something to make a reed out of that gave me the tone I liked, a 1 liter Mountain Dew Bottle. I experimented with different widths and shapes till I came up with the sound I wanted.
To determine the correct sound, I copied a couple howls off of a Sceery Lone Coyote Howling Tape onto a blank tape. I then recorded my howls to see how the tone differed from the recordings of an actual coyote, and tuned my reeds accordingly. I have used this howler for a couple of years (with the different reeds), and it seems to work just fine.
Another howler I like is the "Song Dog". This one comes with two add on extensions for tuning the sound like you want it, as well as several different reeds. This one has a huge air channel, is quite loud, and easy to blow.
One night this fall I was out working, and had seen a Coyote in a hay meadow on the edge of town (small town, population 420). About a half hour later I was up town at the filling station, and was telling a friend about the coyote I had seen. I took the "Song Dog" out of my pocket, and howled twice. Low and behold that coyote answered me. He was about a half mile from me (at least when I saw him in the meadow). You should have seen the looks on the faces of the people standing at the filling station.
Most of the howlers I have bought that I didn't like I have given away. Some of them have made them work, others not.
Larry