diff --git a/doc/4-instrument/c64.md b/doc/4-instrument/c64.md
index 239f07782..a9bb080b6 100644
--- a/doc/4-instrument/c64.md
+++ b/doc/4-instrument/c64.md
@@ -25,7 +25,7 @@ the C64 instrument editor consists of two tabs: "C64" to control various paramet
     - **high**: a high-pass filter. higher cutoff values result in a less "bassy" sound.
     - **band**: a band-pass filter. cutoff determines which part of the sound is heard (from bass to treble).
     - **ch3off**: mutes channel 3 when enabled. not sure why is this part of the chip's design, but it is.
-    - multiple filter modes can be selected simultaneously. for example, selecting both "low" and "high" would combine the effects of both, resulting in a bandpass filter.
+    - multiple filter modes can be selected simultaneously. for example, selecting both "low" and "high" results in a bandstop (notch) filter.
 
 - **Absolute Cutoff Macro**: when enabled, the cutoff macro will go from 0 to 2047, and it will be absolute (in other words, control the cutoff directly rather than being relative).
 - **Absolute Duty Macro**: when enabled, the duty macro will go from 0 to 4095.