Sync Lock: flesh out explanatory comment

src/engine/sync/enginesync.cpp

@@ -616,7 +616,7 @@ void EngineSync::setMasterParams(Syncable* pSource) {
     if (!pSource->isPlaying()) {
         // If the params source is not playing, but other syncables are, then we are a stopped
         // explicit Master and we should not initialize the beat distance.  Take it from the
-        // internal clock instead.
+        // internal clock instead, because that will be up to date with the playing deck(s).
         bool playingSyncables = false;
         for (Syncable* pSyncable : qAsConst(m_syncables)) {
             if (pSyncable == pSource) {