Definitely one for the dealer.

So they're sending me a replacement which works out pretty good in the long run.I originally had an ex display model and i'll be getting a brand new one for the same price which should also contain the disc i need to tune the notch filter system.

If you find anything else out about the notch filter, it would be good to post it to let others know

Yep, no problem, as soon as i figured it out i'll let you know.

After waiting 4 weeks for the replacement there still appears to be no disc for the notch filter system.I've sent an email to mordaunt short asking if it is possible to send me a disc and any info on this system.I purchased the sub from audiovision, and i found the customer service to be very poor, they told me the replacement would take 6 to 7 days and it took 4 weeks and they ignored my emails.I will update you if i have a reply from MS concerning the filter disc, but as for the replacement sub, i'm very happy with it, now after having faulty 309 i could hear the difference almost straight away.The bass sounds more defined and controled, which is very pleasing.All i need to do now is update my speaker cable to the chord odessey and update my cd player from nad 521bee to the nad c542, which is probably a better match for the nad 372.