The WOLF TERMINATOR is designed to eliminate the stuttering or warbling note often found in the F2 to A#2 range when played on the double bass. This problem often occurs on the A and E strings and may sometimes be found on the D string as well. When tuned to the frequency of the wolf note, the WOLF TERMINATOR will enable the note to be played smoothly and with complete control. In addition, selective placement of the WOLF TERMINATOR on the bass top will produce effective suppression of the wolf with minimal effect on the overall tone.
1. Locate the wolf note
Play your bass on the A string to locate the precise position of the wolf note. It will probably occur somewhere between two notes rather than exactly on a single note. On most basses this will be somewhere between G and A, but yours could be anywhere between F and A#. On your own bass you are no doubt familiar with the note(s) which are affected by the wolf, but since the goal is to eliminate the wolf, rather than simply moving it between two notes or making it less noticeable, locating the precise position is important.
2. Prepare the WOLF TERMINATOR for installation
Attach a small amount of the provided removable adhesive to the base the WOLF TERMINATOR. Roll it between your fingers into a noodle as long as the base, as shown in the photo, and press it on.
Save the unused portion of the removable adhesive for future use.

3. Install the WOLF TERMINATOR (temporary position)
The WOLF TERMINATOR should be placed about two inches away from the tailpiece and even with the upper end. For most instruments, this will be a temporary position which allows easier identification of the wolf and convenient access to the frequency adjusting screw.
*Press slowly but firmly onto the top of the bass, using a slight back and forth twisting motion. Hold the body of the WOLF TERMINATOR at the upper corners of the body and avoid touching the metal resonator blades.

4. Eliminate the wolf note
Play the wolf note (located in step 1) and take note of the severity of the wolf. Adjust the eliminator by using the supplied allen wrench. Insert the “ball end” of the wrench into the adjustment screw, taking care not to scratch the bass. Steady the body of the eliminator with one hand and turn the wrench with the other. Turn the screw a half turn at a time, testing for the wolf each half turn. Count the turns. If the wolf hasn’t changed after reaching the limits of adjustment (regardless of direction), return to the original position and adjust in the opposite direction. The wolf note will noticeably diminish and disappear when the eliminator is tuned to the exact frequency of the wolf.
The WOLF TERMINATOR has been shipped with the frequency adjuster preset at approximately G#. When looking at the end of the frequency adjusting screw, clockwise turns will lower the frequency toward F, and counterclockwise turns will raise the frequency toward A#.
The rough adjustments can be done a half turn at a time. When you have localized the tuning, further adjustment can be done a quarter turn at a time. Confirm your adjustments by playing passages in your normal style.
When the frequency adjuster is turned clockwise as far as it will go, the WOLF TERMINATOR will be tuned to the F range. When the adjusting screw is turned counterclockwise as far as it will go, the WOLF TERMINATOR will be tuned to the A# range. Most basses will require tuning in the middle of the range at G to A.
Caution: do not force the adjusting screw beyond these limits as this may cause permanent damage!
You may find it easier to tune the WOLF TERMINATOR by playing the wolf note on the E string. Because the wolf note is much more pronounced on the E string and requires more critical tuning of the WOLF TERMINATOR, suppression of the wolf on the E string may produce more accurate results in less time. Check for the wolf note on the A string and adjust further if necessary.
If you have a friend available to help, you can have your friend adjust the WOLF TERMINATOR while you continuously play the wolf note. You will hear the wolf note gradually diminish and disappear………… all in less than a minute!

5. Move the WOLF TERMINATOR to its permanent position
Once you have achieved success with eliminating the wolf, you can move the WOLF TERMINATOR to a less noticeable position. You can reduce the amount of suppression to the exact amount needed to counter the wolf and minimize the eliminator’s effect on the overall tone of the bass. This is accomplished by moving the eliminator toward the tailpiece and downward toward the lower end of the bass.

Remove the eliminator by lifting up slowly while twisting back and forth. Any pieces of the removable putty which remain on the bass can be removed by gently rolling a finger over the pieces until they form into a ball which can then be lifted off and pressed back onto the base of the eliminator.
Reattach the eliminator so that it is an inch outside of the tailpiece and an inch below its upper edge. The tuning of the eliminator may have to be readjusted slightly. Play the bass and adjust if necessary. In stages, try moving the eliminator slightly further toward the tailpiece and/or down toward the lower end of the bass. With each successive step, listen for wolfs and readjust if necessary. Go back to the previous location if the wolf reappears. Because each bass will react differently to the WOLF TERMINATOR, you may wish to try several positions in order to find the best compromise between wolf suppression, visual appearance, and overall tone.


The photos above show some of the possible permanent positions for the WOLF TERMINATOR. The device may be oriented either crosswise or lengthwise with the frequency adjustment screw facing in any direction. The orientation of the eliminator may affect the frequency adjustment, however, so if you remove the eliminator and later reattach it to your bass, be sure to place it in exactly the same spot and with the same orientation.
Additional notes and observations
Bass wolf notes may vary in frequency and intensity due to seasonal and weather changes. In addition, changes to the instrument due to maintenance and setup – including replacement or adjustments to the soundpost, bridge, strings and tailpiece- will also affect wolfs. Because the WOLF TERMINATOR is easily tuned, corrections can be quickly and effectively made. Check regularly to see that the Wolf Terminator is securely attached to the top. There are several screws on the eliminator which are shop adjusted and permanently set. The only adjustment to be made by the player is the single (frequency) adjustment screw at the end of the device.
You may find an improvement in tone and response when playing an octave below the wolf note on the E string. In addition, when playing pizzicato on the wolf note and in the octave above, you should notice improved sustain and uniformity of tone compared to the surrounding notes.
Moving the Wolf Terminator between two basses can be easily done because of the adjustable tuning feature and the use of the removable adhesive. Keep in mind, however, that because the body resonances of a bass interact with the tuning of the WOLF TERMINATOR, it is impossible to calibrate the WOLF TERMINATOR note by note. The frequency adjustment to suppress a G wolf on one bass will probably require a little retuning to suppress the same G wolf on another instrument. The WOLF TERMINATOR may also be removed when not required. When needed, just place it back in the same position and orientation as before.
*As a precaution, test the adhesion of the WTB-2 by pressing down with the twisting motion daily. The adhesion improves over time, but it is best to check the adhesion on a regular basis.
For further information and additional suggestions for installation and use, please visit us at: wolfterminator.com. We are confident that the installation of the WOLF TERMINATOR will enable you to “terminate” your wolf once and for all!