Got wood? TreeVerb wooden plate reverb
Today I came across something that I’ve definitely never seen before – a plate reverb made of wood, called the TreeVerb.
A conventional plate reverb system uses an electromechanical transducer, similar to the driver in a loudspeaker, to create vibration in a large plate of sheet metal. A pickup placed somewhere else on the plate, picking up the vibrations as they bounce across the plate, and the result is output as an audio signal. The reverb time can be mechanically adjusted by a damping pad, usually made from framed acoustical tiles. The closer the damping pad, the shorter the reverb time.
We now come to the TreeVerb™, a plate reverb that uses a single sheet of aged wood instead of a metal plate. First imagined by Bill Mareci of Audio Rents in L.A., TreeVerb was created not from experimentation and science, but from a “hey, wouldn’t it be cool if…” sort of thought.
His partner, Bob Burton explains:
“With the economic downturn, it was a slow day at the shop last week so both Bill and I found ourselves with nothing to do but ‘plant’ the seeds of TreeVerb. When you consider that guitar-makers prize and harvest certain species of trees known as “tone woods,” it makes perfect sense that a good solid piece of the right wood would make an excellent medium for sound reverberation.”
The team started with a 4 x 8 wood sheets (hey, they’re easy to find at the hardware store!) suspended by springs. They then experiemented with contact mics to find the location on the sheet that had the most pleasing sound and then they connected these mics to a stereo preamp.
“Getting a useable reverb sound out a piece of wood is no small task,” says Mareci. “My research revealed ingrained problems I had overcome by using special audio processing of both the audio signal sent into the TreeVerb as well as the recovered audio coming back off the wood.”
They created a special circuit to feed the plate, called the “Cellulose Compression Curve Compensator™”, which expands the audio so that it will travel through the wood in an efficient and musical way.
“Since any remaining pockets of sap left (after kiln drying) can be detrimental to the high frequency response of the reverb’s decay, a special dynamic Sap Suppressor or Sappressor™ is used to counteract the capillary action of any granularly whorls.”
After the sound passes through the wooden plate, it then needs to be further processed to reverse the frequency response loss that the wood imparts on the sound (which they call the “K-factor”). The audio then passes through their “Knot Equalizer™”, which corrects non-linear distortion from random knots in the wood. They claim that harder woods like oak or mahogany require less processing, while softer woods such as ash or pine may require much more.
TreeVerb, although still at the production prototype stage, will be available using a variety of exclusive eco-friendly tone woods. So far they have created plates out of sequoia and avocado wood. Other “sonic veneers” in development are the “Floater” model using only balsa wood for the lightest sound, and for heavier rock music, the mahogany ThunderRose model.
So what does this thing sound like?
Check it out for yourself:
|Guitar strum (dry):
|Snare drum (dry):
The TreeVerb definitely has an unmistakable sound of wood, and a nice, mellow vibe. What do you think?
For more information, contact them at treeverb (at) gmail.com.
- wood plate reverb