Having ordered the Loksound chip from Richard of DCC Concepts and it arrived as promised I set to work on the install. The reason I wanted to add this post was I feel with some minor & or major work further improvements to the sound can be made; I'll try to take some pictures over Xmas and post.
Having studied Richard's great topic on this diesel, I set to work & the Deltic was duly fired up last night and with just one LS speaker (rectangular) that fits in the slot in place, I was impressed, (see wife rushing out to say "oo's making those announcements and I can hear that flippin whistle from here so pack it in I'm watching telly" ) Anyway, I have decided that it really is worth milling out so am dropping a base reflex into each end I tried it first without the body on on in series and parallel and the difference is astonishing, and I mean astonishing! This was a bass reflex at each end.
One tip for anyone doing this one as a sound project, as the roof fans don't move unless you blow them or fit electronic blowers (and who really does that) I removed the internal casing holding them, used a dremel with a fine circular sander to smooth the collars (inside roof) and smoothed away the lugs nearby, re-fixed the fans without the casing and gained a considerable amount of headroom, from outside the body you can't see the difference; now all I need to do is get the milling done (later today) and fire her up.
Spookily the slot on the chassis where the two speaker set up was shown accommodates a rectangular bass reflex speaker but does require milling of metal; the plastic body internal sanding and fan changes simply allow quite a bit more headroom and consequently with a flatter bass speaker more air to distribute sound; on the trial with a pair of BR (base reflex) speakers (prior to milling) I had to turn sound down on CV63 to 40, currently it is at 36 which is perfect (IMO) and does not let the amp run at full pelt.
Even if you don't fancy the metal milling, the changes to the inside of the plastic body mean you can get taller speakers in if you so wish or even on the twin 23mm speaker idea with bespoke baffle box it permits a slightly bigger box to be made. Setting CV 3 to 50 gives a really slow and impressive take off, (trouble is I want to keep stopping so I can use the excellent guards whistle and that SUPERB & FUN station announcement.
I know it's probably hard to follow without pictures so I will do my best to get them on soon.
Again with full credit to the excellent sounds of the Deltic from Richard at DCC Concepts. http://www.dccconcepts.com/