FYI this is the most common route flown between EWR and MIA ...
ELVAE COL WHITE J209 SBY KEMPR DIW AR22 JORAY HILEY2
EWR departure ...
http://aeronav.faa.gov/d-tpp/1113/00285NEWARK.PDFMIA arrival ...
http://aeronav.faa.gov/d-tpp/1113/00257HILEY.PDFEnroute charts ...
http://skyvector.com/These are the standard frequencies (altitudes) used on this route ....
New York Departure 119.200 (to 6000)
New York Departure 124.750 (to 17000)
New York Center 118.975 (to FL240)
Washington Center 121.025 (to cruise altitude - even, ie: FL320/FL340/FL360/FL380/FL400)
Washington Center 121.375 (FL360 and above)
Washington Center 120.975 (FL340 and below)
Washington Center 120.750 (FL360 and above)
Washington Center 133.825 (FL340 and below)
Washington Center 118.825 (FL360 and above)
Washington Center 124.025 (FL340 and below)
Jacksonville Center 120.125 (FL380 and above) (sector used when required, otherwise merged into lower sectors)
Jacksonville Center 135.050 (FL360 and below - north)
Jacksonville Center 134.850 (FL360 and below - south)
Miami Center 128.650 (FL360 and above, to FL350) (sector used when required, otherwise merged into lower sector)
Miami Center 119.825 (FL340 and below, OSOGY at FL240)
Miami Center 132.150 (MILSY at 16000 - landing east, MILSY at 13000 - landing west)
Miami Approach 120.500 (landing east)
Miami Approach 124.850 (landing west)
AFAIK the only enroute Center frequencies covered here on LiveATC are Jacksonville 135.050 and Miami 132.150
.