Shame on me!
When giving you the volume of the enclosures that i listened to at my friend place i gave the right external dimensions but the internal volume is 8.26 cubic feet( that is in good French 230 liters and not 320 liters!).So forget about the11.3 cb ft that i mentionned at the beginning of the post and which made the enclosures so big for a pair of 604.
I dont know wether this is going to encourage you to help me or to prevent you to do so.We shall see.
Dyslexic Charly.