tips for big malty flavour

i usually brew hoppy beers and iv got them nailed down to where i want but i wanna brew a northern brown ale, its gonna be around 4,5%
what can i do to accentuate the malty flavours at this ABV
what kinda water additions and any other tips or tricks?

Do you have a recipe? AG or extract? I would suggest going easy on the hops, using mild, earthy, low alpha strains early in the boil. You can add dark DME or LME to the boil but it'll change your OG.

#1 - Use a quality flavorful base malt. Maris Otter, Golden Promise, even Avangard Pale Ale.
#2 - Use a characterful yeast that gives some nice english esters. WLP002 is probably a good start.

recipe is

BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: Brown Ale
Brewer:
Asst Brewer:
Style: Northern English Brown Ale
TYPE: All Grain
Taste: (30.0)

Recipe Specifications
--------------------------
Boil Size: 22.35 l
Post Boil Volume: 17.00 l
Batch Size (fermenter): 17.00 l
Bottling Volume: 17.00 l
Estimated OG: 1.046 SG
Estimated Color: 18.0 SRM
Estimated IBU: 22.8 IBUs
Brewhouse Efficiency: 73.00 %
Est Mash Efficiency: 73.0 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt Name Type # %/IBU
2.90 kg Pale Malt, Maris Otter (3.0 SRM) Grain 1 84.1 %
0.35 kg Caramel/Crystal Malt - 40L (50.8 SRM) Grain 2 10.1 %
0.10 kg Pale Chocolate Malt 225L (305.0 SRM) Grain 3 2.9 %
0.10 kg Special B Malt 250L-400L (200.0 SRM) Grain 4 2.9 %
25.00 g Goldings, East Kent [5.00 %] - Boil 60.0 Hop 5 19.4 IBUs
8.00 g Goldings, East Kent [5.00 %] - Boil 15.0 Hop 6 3.4 IBUs
1.0 pkg SafAle English Ale (DCL/Fermentis #S-04) Yeast 7 -

sorry bout the KG's just go by the %
any pointers on chloride to sulfate ratio?? or even sulfate amount? would 50ppm be ok for the sulfate?

I think 50ppm on the sulfate would be good. As far as the chloride/sulfate ratio, I would shoot for something in the 1.25-1.50 range to accentuate the malty character of the beer.