Just read the rest of your post, too... not having silencers on your string will definitely change the sound of the shot. You can either replace them with Sims string leeches (I'd recommend using the crossbow variety) or use a good suppressor such as those made by MeanV that will screw in your rear stabilizer bushing if you want ...

You still need to devote some attention to your mod screws and make sure they're ok as well though.