If the sound output from your SoundFX decoder is distorted, try the following:
1. Check the speaker cone for magnetic debris that may have collected there. Debris on the speaker will cause a loss of sound quality and must be removed. This is a common problem in speaker installed facing down toward the track. Remember, speakers are magnetic and will vacuum up magnetic debris along the track.
2. Be sure that the CV58 volume is not set at a level that is too high for the speaker. For impedances below 32ohms (e.g. 8 to 30 ohms) set the volume setting lower to ensure the 1 watt output rating is not exceeded.