The double top with the 9 braces Hauser fan, was developed and introduced by  Master Luthier Manuel Contreras the II at the end of the 70s and reached its peak in the 80s. In this Variation of the Double top, a second top is located halfway between the main top and the back. It is held in place by means of little Mahogany bridges located above and below the second top along the inner part of the sides (frames 1 & 3). The second top rests on the upper bridges and once it is glued on each little bridge (frame 2), a second bridge is glued on top of the preceding corresponding bridge below the second top (frame 3). This second top vibrates a fraction of a second after the first one creating an immense sustain and punch using the air moving inside the sound box and thus creating a multiplying effect of the sonorous waves.

Sinker logs (top #2), are pulled from the bottom of lakes and rivers. Sometimes, scuba divers are needed to achieve the extraction.  Most of these logs are hundreds of years old (In one of the pictures above, you can see that the tree was cut with an hatchet). Due to a series of factors (The logs were too big and heavy to be pulled out of the rivers or the logs were caught by currents and were sucked to the bottom)  these logs were trapped by the muddy buttons of these water beds and this created like a time capsule where the wood was preserved in fantastic humidity conditions that made the wood season in a slow natural way during many centuries. Some of the logs are selected for musical instruments construction. The sound that these woods produce is unique and the grain has a beautiful coloration that changes according to the type of mud present in the water bed.