What is Mwah
Posted: Sun Apr 19, 2009 7:57 pm
Mwah (sometimes spelled Mwaa), is a tonal characteristic unique to fretless string instruments such as electric fretless bass. The upright bass also has a similar sound characteristic but it is usually called growl. To the best of my knowledge, Mwah has not been scientifically analyzed, however I have a fair idea of what creates the sound.
The characteristic Mwah sound differs somewhat with each bass but there are similarities. The sound imparts a blooming, growling characteristic that is part of the timbre of the note. Most fretless players regard this sound as desirable and seek to emphasize it when appropriate.
Lower pitch notes generally seem to manifest more Mwah while higher notes get less. This can be adjusted to be more equal by altering your instrument set-up and/or lowering or raising the action of each string until they have about equal amounts of Mwah. This difference has to do with the amount of energy and friction a particular string has when vibrating. Generally, larger strings store more energy.
Mwah is a byproduct of friction that results in an altered string timbre (tone).
When the fretless player presses a string against the fingerboard, and that string is plucked, the vibrating string and the fingerboard interfere starting at the area where the intonating finger is pressing, and away from that point a distance approximately 1/4 tone depending on flatness of the fingerboard (relief). I call this the Mwah Interference Zone (MIZ).
Again, considering an intonated, plucked string, this time looking at it from the oscillating portion toward where the intonating finger is pressing. This Mwah Interference Zone between the fingerboard and the string is in the shape of a wedge or taper where the string comes increasingly close to the fingerboard ultimately establishing solid contact at the intonation point. Because the string is vibrating and the distance between the string and fingerboard diminishes, at a certain point the vibrating string begins to contact the fingerboard even though the intonation point has not yet been reached.
When the vibrating string contacts the fingerboard in the Mwah Interference Zone, friction is the result. Greater friction is the key to achieving more Mwah. As the moving string rubs on the fingerboard (friction) a certain amount of string energy is damped from it, part of this damped energy is returned into the string as overtones and/or partial overtones (noise) that are the defining characteristic of Mwah. This noise is then amplified and made audible along with the primary string vibrations.
The longer the Mwah Interference Zone the greater the friction, and the better the Mwah characteristic will be. Thus it is very important to adjust your neck to have very little to almost no relief curvature. It is possible to get too much Mwah if the neck is absolutely straight or in a back-bow. A properly adjusted fretless bass neck must have a fingerboard that is without defects such as "S" bends, high spots, low spots, or twists.
Proper set-up is critical to achieving Mwah. Your action should be fairly low depending on set-up preferences. Make sure your bridge is low enough to get good Mwah but not so low that there is excessive noise and buzzing.
Because round-wound strings create more friction than smoother flat wounds they also provide a more distinctive Mwah.
The hardness of the friction surface (fingerboard) effects the timbre or tone of Mwah. Soft surfaces such as natural wood have a mellower Mwah tone whereas hard surfaces impart a more noticeable wider (and higher) frequency Mwah. In general, hard fingerboard surfaces enhance Mwah.
The Mwah sound seems to be centered around 700Hz, adding EQ in this range may help your Mwah speak better if needed.
Your calluses also add to Mwah. If your finger pads are soft there will be more dampening, less sustain, and less energy returned to the string as Mwah.
The characteristic Mwah sound differs somewhat with each bass but there are similarities. The sound imparts a blooming, growling characteristic that is part of the timbre of the note. Most fretless players regard this sound as desirable and seek to emphasize it when appropriate.
Lower pitch notes generally seem to manifest more Mwah while higher notes get less. This can be adjusted to be more equal by altering your instrument set-up and/or lowering or raising the action of each string until they have about equal amounts of Mwah. This difference has to do with the amount of energy and friction a particular string has when vibrating. Generally, larger strings store more energy.
Mwah is a byproduct of friction that results in an altered string timbre (tone).
When the fretless player presses a string against the fingerboard, and that string is plucked, the vibrating string and the fingerboard interfere starting at the area where the intonating finger is pressing, and away from that point a distance approximately 1/4 tone depending on flatness of the fingerboard (relief). I call this the Mwah Interference Zone (MIZ).
Again, considering an intonated, plucked string, this time looking at it from the oscillating portion toward where the intonating finger is pressing. This Mwah Interference Zone between the fingerboard and the string is in the shape of a wedge or taper where the string comes increasingly close to the fingerboard ultimately establishing solid contact at the intonation point. Because the string is vibrating and the distance between the string and fingerboard diminishes, at a certain point the vibrating string begins to contact the fingerboard even though the intonation point has not yet been reached.
When the vibrating string contacts the fingerboard in the Mwah Interference Zone, friction is the result. Greater friction is the key to achieving more Mwah. As the moving string rubs on the fingerboard (friction) a certain amount of string energy is damped from it, part of this damped energy is returned into the string as overtones and/or partial overtones (noise) that are the defining characteristic of Mwah. This noise is then amplified and made audible along with the primary string vibrations.
The longer the Mwah Interference Zone the greater the friction, and the better the Mwah characteristic will be. Thus it is very important to adjust your neck to have very little to almost no relief curvature. It is possible to get too much Mwah if the neck is absolutely straight or in a back-bow. A properly adjusted fretless bass neck must have a fingerboard that is without defects such as "S" bends, high spots, low spots, or twists.
Proper set-up is critical to achieving Mwah. Your action should be fairly low depending on set-up preferences. Make sure your bridge is low enough to get good Mwah but not so low that there is excessive noise and buzzing.
Because round-wound strings create more friction than smoother flat wounds they also provide a more distinctive Mwah.
The hardness of the friction surface (fingerboard) effects the timbre or tone of Mwah. Soft surfaces such as natural wood have a mellower Mwah tone whereas hard surfaces impart a more noticeable wider (and higher) frequency Mwah. In general, hard fingerboard surfaces enhance Mwah.
The Mwah sound seems to be centered around 700Hz, adding EQ in this range may help your Mwah speak better if needed.
Your calluses also add to Mwah. If your finger pads are soft there will be more dampening, less sustain, and less energy returned to the string as Mwah.
