Goldline FD23 Feedback Detector Rental

fd23 2We offer Goldline FD23 Feedback Detector rentals in Chicago, the Chicago suburbs, and nationwide.

If you have any questions about a Goldline FD23 Feedback Detector rental in Chicago, suburban Chicago, or nationwide, or to reserve your rental, contact our Rental Team at 847.367.9588 or

The Goldline FD23 Feedback Detector is just one of many pieces of audio testing equipment in our rental inventory.

Generally, feedback (ringing) is a self-sustaining and erroneous oscillation that occurs when sound arriving at a microphone is greater than the sound produced by the person or instrument using that microphone. Feedback is controlled through the use of a graphic or parametric equalizer, and these units are most effective when the sound engineer can quickly recognize the frequency at which feedback is occurring. The FD23 provides a quick, inexpensive means of detecting which frequency is causing the feedback.

The FD23 operates in the same manner, using the same filter design that is found in Gold Line’s spectrum analyzers. Ease of operation is through a single on/off/sensitivity control. If a frequency is ringing and the
sensitivity is set accurately, the display of the FD23, which has LEDs for standard ISO third-octave frequencies from 80Hz to 12.5kHz, will light an LED representing the frequency that is ringing (within that frequency’s tolerance). Most equalizers have adjustments (sliders) at the same frequencies and by moving the slider that matches the frequency indicator on the FD23 you will reduce the feedback. If the sensitivity of the FD23 is set too high, many LEDs will light, making it difficult to know what frequency is ringing. If the sensitivity is too low, you will not see any LEDs lit. The FD23 can also be used in situations where feedback is not actually happening. By carefully adjusting the FD23’s sensitivity, you can detect a frequency that is building up (but not necessarily feeding back). You can then use the equalizer to reduce the buildup.

The FD23 is a rugged, inexpensive, hand-held instrument that can be used with either alkaline or nicad batteries. It can also be powered with a wall-wart providing 12Vdc @ 200mA. To install or change batteries, remove the four screws that hold on the back cover. Separate the cover from the unit being careful not to pull on the power leads. Select either nicad or alkaline with the internal switch provided. Observe the polarity markings in the battery boxes. Nicad batteries can be recharged through the external power jack.

TC Furlong offers Goldline FD23 Feedback Detector rentals alongside  many other pieces of audio testing equipment and an extensive rental inventory of professional audio equipment.

Contact the TC Furlong Rental Team today to rent the Goldline FD23 Feedback Detector in Chicago, Suburban Chicago, or nationwide, at 847.367.9588 or

Goldline FD23 Feedback Detector Rental Documentation:

Goldline FD23 Rental Manual (PDF)