Improved UI

internal/datasource/synthetic/dsp_bridge.go

@@ -99,6 +99,16 @@ func buildNode(d NodeDef) (dsp.Node, error) {
 	case "expr":
 		return &dsp.ExprNode{Expr: stringParam(p, "expr")}, nil
 
+	case "lowpass":
+		order := int(floatParam(p, "order"))
+		if order < 1 {
+			order = 1
+		}
+		return &dsp.LowPassNode{
+			Freq:  floatParam(p, "freq"),
+			Order: order,
+		}, nil
+
 	case "lua":
 		return &dsp.LuaNode{Script: stringParam(p, "script")}, nil