Low PH and Dull flavor with Brown?

Do ya think a low mash PH of 5.2 to 5.3 will result in more of a “dull” characteristic in the finished beer? An American Brown ale

Not dull so much in this beer. In roastier beers (brown, porter, stout), a lower pH can emphasize the very roasty, sometimes acrid, aspects of the roasted malts. Obviously there is a lower % of roasted malt in a brown as opposed to porter and stout. Just try it and see what you think. I target 5.5 as my pH in Bru’nWater for these styles, which I feel gives you a softer, more balanced roastiness. You’ll have to post your final results - good luck !

I ask because i am frustrated because i attempted this recipe this AM with shooting for a 5.6PH and ended up with 5.0 at that so i dumped it and re did the water  and cont to have a lower PH than i desire. I have never had this issue before my water must have changed because i have quit a bit of bicarb. 
Finished Profile ppm
Ca 100
Mg 20
Na 24
SO4 51
Cl 65
HCO3 308

Hardness 332
Alkalinity 254
RA 171
SO4/Cl 0.78

SRM: 20.2 SRM SRM RANGE: 18.0-35.0 SRM
IBU: 44.9 IBUs Tinseth IBU RANGE: 20.0-40.0 IBUs
OG: 1.058 SG OG RANGE: 1.045-1.060 SG
FG: 1.014 SG FG RANGE: 1.010-1.016 SG
BU:GU: 0.772 Calories: 151.6 kcal/12oz Est ABV: 5.8 %
EE%: 73.00 % Batch: 3.25 gal      Boil: 4.90 gal BT: 60 Mins

—WATER CHEMISTRY ADDITIONS----------------

Total Grain Weight: 7 lbs 3.7 oz Total Hops: 2.14 oz oz.
—MASH/STEEP PROCESS------MASH PH:5.50 ------

-ADD WATER CHEMICALS BEFORE GRAINS!!<<<<<<<
Amt                  Name                                    Type          #        %/IBU       
4 lbs 9.8 oz          Pale Malt - 2 Row (Cargill) (2.0 SRM)    Grain        1        63.8 %       
1 lbs 2.5 oz          Aromatic Malt (26.0 SRM)                Grain        2        16.0 %       
7.0 oz                Crystal, Medium (Simpsons) (55.0 SRM)    Grain        3        6.1 %       
7.0 oz                Oats, Golden Naked (Simpsons) (10.0 SRM) Grain        4        6.1 %       
7.0 oz                Special B Malt (115.0 SRM)              Grain        5        6.1 %       
2.3 oz                Chocolate (Briess) (342.0 SRM)          Grain        6        2.0 %

Name              Description                            Step Temperat Step Time   
Mash In          Add 3.16 gal of water at 168.1 F        153.0 F      60 min

—SPARGE PROCESS—

-RECYCLE FIRST RUNNINGS & VERIFY GRAIN/MLT TEMPS: 65.0 F/68.0 F
-ADD BOIL CHEMICALS BEFORE FWH
Fly sparge with 2.60 gal water at 168.0 F
Amt                  Name                                    Type          #        %/IBU       
0.29 oz              Willamette [6.50 %] - First Wort 60.0 mi Hop          7        11.0 IBUs

—BOIL PROCESS-----------------------------
Est Pre_Boil Gravity: 1.045 SG Est OG: 1.058 SG
Amt                  Name                                    Type          #        %/IBU       
0.30 oz              Columbus (Tomahawk) [15.20 %] - Boil 60. Hop          8        24.2 IBUs

Amt                  Name                                    Type          #        %/IBU       
1.55 oz              Willamette [6.50 %] - Steep/Whirlpool  1 Hop          9        9.7 IBUs

How do you check your pH, out of curiosity ?  Paper strips are worthless IMO - the colorphast strips are better, but read low.

A Milwaukee 101 meter at room temp 77F, calibrated every other batch with a 2 point solution. My solution is a year old and i have been wondering if i should replace it.  I use brunwater and am most of the time within a tenth of a point of what it predicts. i will re post with tasting results

i will hope that with only 2% truly roasty/Cholo malt that it will not be as acrid

How about your water?  I use RO water from a grocery store machine and build, but I only recently bought a TDS meter (~ $20) off Amazon. Stores can be pretty unreliable about the integrity of the membrane in their machine and “RO” water can sometimes be not so much so. I bring the (small) meter to the store and check the water before I buy any each time. It’s a cheap easy way to GUARANTEE the quality of your water. Definitely worth $$.

I do the same. Great idea on the TDS meter never even thought of that. Being my HC03 is always so high i always cut my water with RO. I normally dont for my darker beers and have always been in the range/5.5ish however i have never made this recipe with this grain bill. just started my boil with a 5.4 PH and am using WLP007 and i know this yeast does not buffer that well so i am predicting that i will have a low finial PH also, i hope not but it may push low 4’s