| Instrument | cello |
| Aubert number | 18L |
| Quality grade | De Luxe top grade |
| Model | Belgian |
| Condition | Blank, uncut |
| Material | Maple |
| Country of manufacture | France |
| Foot widths | 88 mm / 90 mm / 92 mm / 94 mm |
On a cello bridge the two main resonances lie around 1 kHz and around 2 kHz; both are torsional modes, twisting vibrations of the long bridge legs. On a 4/4 cello the bridge stands around 91 mm high as a guide, with a foot width of 90 mm, a thickness at the chest of 9 mm and a projection of 82 mm; the strings cross the bridge at around 153°. This height strengthens the coupling to the top plate and with it the transmission in the bass; it also makes a wolf note more likely, a note at which string and body resonance couple so closely that the tone jumps.
At the cello bridge, measurements show three characteristic regions around 165 Hz, between 280 and 400 Hz and between 620 and 880 Hz, which are regarded as the formant regions of the cello, comparable to the formants (characteristic frequency bands) of the human voice.
On a 4/4 cello the fingerboard projection, measured from the top edge of the fingerboard to the top plate, is around 65 mm; together with the bridge projection of 82 mm it determines the string height.
The maple of a bridge blank (density around 650 kg/m³) is around five times as stiff in bending along the grain as across it. Modulus of elasticity and damping (how quickly a vibration dies away in the wood) vary from tree to tree by around ±25 and ±50 per cent, so that even boards from the same tree turn out differently.
Aubert sorts its blanks into quality grades that can be read from the number; the pattern carries its own marker, such as the B for the Belgian model. 'Aubert Mirecourt' is the house stamp and at the same time the name of the basic grade; above it come 'Luxe' and, as the highest of the grades we carry, 'De Luxe', recognisable by the L in the number.
Our experience: the right bridge height belongs to the individual cello; it differs from one instrument to the next and is therefore measured on the instrument itself. In our own cello range we rely on Aubert, using the Aubert Luxe on the Antique cello.
For 4/4 cellos Aubert supplies bridges numbered 14 to 20, among others, in foot widths from 86 to 96 mm. The widths for this version are listed in the variant selection.
Around 1 kHz and around 2 kHz; both are twisting vibrations of the long bridge legs.
Around 91 mm at the centre on a 4/4 cello, as a guide. The exact figure follows from the fingerboard projection and bridge projection of the individual instrument.
It denotes the quality grade of the blank. Above the basic grade 'Aubert Mirecourt' come 'Luxe' and 'De Luxe'; the L in the number stands for De Luxe.
Because every bridge is fitted to its own instrument: the violin maker sets the feet, height, thickness and curve on the instrument itself. How well the feet fit the top plate helps determine how the vibration is transmitted.
No, Aubert marks its grades by number and name. We know stars as a grading mark from other makers, Teller bridges for example.
These texts hold decades of experience and a great deal of heart. They are protected by copyright, C.A. Götz jr. GmbH. Please ask us before any use. Thank you for your appreciation.