This is the end result of my Yamaha NS-1000M tweaks and experimentation.
Over nearly 4 years, I have gone through various stages of re-capping, full digital active set up, use of different drivers, analogue active and semi active approaches. It has spread across several long threads and is difficult to follow, in terms of chronology and my reasoning.
I found the best results were achieved using a semi active solution using a replacement Scanspeak bass driver as pictured above.
For anyone interested in this, the easiest way to follow what went into this final version, is to read the "NS-1000M Upgraded" project on my website. This is a concise build record, specific to just this version and covers details of parts for the analogue and active x-overs as well as cabinet construction, listening notes and bass measurements.
Find it here: http://www.jkwynn.co.uk//YamRev_HTML/YamRev_Thumbs.html