i know what you are saying blue, i do feel a little cruel!!
But the issue here isnt that he has tried to make something and got it a bit wrong - i wouldnt usually mock somebody for that... The issue is that hes trying to pass it off as something good, and whats worse - he is trying to sell it as a proper instrument!!!!
If he had made this for personal use i would be very supportive to his experiments. i would offer constructive criticism where i think he had gone wrong and if he listened he would probably end up with something at least playable.
as soon as i put it up for sale he opened himself up for public humiliation, and his attitude doesnt help!!!
Here is a 'sound clip' over a slideshow:
http://uk.youtube.com/watch?v=V3y73rYHdnwLets just say there is no way those bass sounds are coming from that bass and leave it at that!!
I am all for extended range basses - still not sure how people play them but there are lots of very talented luthiers experimenting with designs.
here is a nice well made 10 string:
http://www.melodiamusik.com/musical/images/img_w300/Foto_17%20-%2010%20string%20Bass%20Jerzy%20Drozd_w300.jpg9 is really a more common number:
http://www.veilletteguitars.com/program_generated/blogs/images/veillette/1158847482.jpghere is a guy that plays 9,11 and 12 string basses and is apparently having a 13 string made (not by this guy though):
http://www.myspace.com/jeanbaudinSo, in theory i must say i am not against the idea of a 13 string bass.... this thing would be just as bad if he had made it as a four string!!!!