From my personal experiance with acrylic calls, I would agree with you that they can be very loud. They can also be played softly. The tone board plays a large role, but you will find that the material, hard as it is, tends to transmit sound very smoothly from the toneboard through the barrel of the call.
This is also true of calls made from Dymondwood if they are sanded and finished inside. It can also be true of any wood call that is given a smooth bore and a hard finish on the inside, though not quite to the extent of acrylic.
Keep in mind that a custom call is much different from a mass produced call. The call maker has the ability to tune a toneboard to the way you want the call to sound, and to the volume you want the call to produce.
If you want a custom acrylic call that blows raspy at low volumes, that can be accomplished. If you want one that is going to reach out there and pull them in from 5 miles away, that too can be accomplished. Be aware that there is always a trade off. A call that blows raspy at low volumes may tend to lock up when you try to get on it. One that is made to reach way out there may not do so well when blown softly.
Now all calls will make sound, usually, at different volumes, but they will preform best when played the way they are designed, and that is one of the big advantages of working with a custom call maker over mass produced calls.
It's also why most of us carry more than one call in the field.
To bear this out, the standard commercial call by which all other commercial calls are judged is the Crittr Call. If you explore the Crittr Call line, you wil see that they have 4 different calls - at least from my book anyway. Each for different purposes.
So don't despair if you want an acrylic call that is going to work the way you want it, because you can have your cake and eat it too.
Al
THO Game Calls