Small Aircraft; High Wing; 1 Eng; Fixed Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 10
Distraction; Confusion
ATC Issue All Types; Conflict NMAC
Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Aircraft
I assigned Aircraft X a discreet squawk code and identified aircraft northwest of OMN.  Pilot request for a full stop at DAB.  Issued traffic to Aircraft X which pilot reported in sight.  I issued pattern entry instructions to 7L at DAB and advised Aircraft X to maintain VFR at 1;600.   Arrival was at an adjacent scope and I was handing off my VFR arrivals at 1;600 feet.  I had two other VFR arrivals ahead of Aircraft X; two VFR aircraft holding over the OMN VOR @ 020 and 025.  I had a VFR point-out from M-ar scope over XFL leaving my airspace and a VFR arrival to OMN crossing west of DAB at 021.  Aircraft X reported that previous issued traffic had turned back toward him and that he had made an 'evasive' maneuver.  I was giving instructions for the OMN arrival when Aircraft X advised that he had a 'close call' with Aircraft Y.  When I returned my attention to Aircraft X and saw VFR target indicating 016 (unverified; limited data block) west of Aircraft X moving west.  As the pilot had reported the traffic and target was moving away; I only acknowledged with; 'Roger'.   Moments later Aircraft X advised he 'had a near miss.'  I advised the FLM.At the time the report was made I was unsure if Aircraft Y was the previous issued traffic or a new target.  After being advised that air traffic was looking into the NMAC; I reviewed the radar playback and saw that Aircraft Y had departed OMN and started a climb once he was clear of the DAB Class Charlie.  The playback revealed that a conflict alert had gone off (very common in DAB airspace with the concentration of aircraft); but I did not recall hearing it; and subsequently had not issued a traffic alert. After reviewing my pref sets for the radar position; I determined that my audible alarm was at a lower setting (2); and my LDB's (Limited Data Blocks) intensities were set much lower than my full data blocks.  While I had not previously had a problem with these lower settings; I intend to adjust to higher levels on both and be sure to check them each time I sign onto position.
DAB Approach/Departure Controller reports of a near miss with a VFR aircraft that he was not talking to or was under his control.