Robert Bass said:
Radio Truth,
Let me ask you a serious question. Have you ever looked at a modulation monitor while tuned to any given station in this market? The FCC rules specifically state that modulation is to be between 80 to 100 percent, no more and no less. Looking at KEOM’s signal on a MM reveals that KEOM’s modulation is within the rules. I’ve seen the modulation signal on quite a number of other stations in this market, and most of them exceed 100% modulation by up to 3%. So technically, the louder stations are breaking FCC regulation.
Actually, no (depends on WHOSE monitor you are using). The newer faster mod monitors would show them to be legal..and if their equipment is Type Accpeted then an inspector would not cite them. There arer also reasons to exceed 100% (as noted below).
BTW, the rules actually state:
Sec. 73.1570 Modulation levels: AM, FM, TV and Class A TV aural.
(a) The percentage of modulation is to be maintained at as high a
level as is consistent with good quality of transmission and good
broadcast service, with maximum levels not to exceed the values
specified in paragraph (b). Generally, the modulation should not be
less than 85% on peaks of frequent recurrence, but where lower
modulation levels may be required to avoid objectionable loudness or
to maintain the dynamic range of the program material, the degree of
modulation may be reduced to whatever level is necessary for this
purpose, even though under such circumstances, the level may be substantially
less than that which produces peaks of frequent recurrence at a level of 85%.
(<--- not 80)
(b) Maximum modulation levels must meet the following limitations:
*****(I skipped the AM stuff) ******
(2) FM stations. The total modulation must not exceed 100 percent on
peaks of frequent reoccurrence referenced to 75 kHz deviation. However,
stations providing subsidiary communications services using subcarriers
under provisions of Sec. 73.319 concurrently with the broadcasting of
stereophonic or monophonic programs may increase the peak modulation
deviation as follows:
(i) The total peak modulation may be increased 0.5 percent for each
1.0 percent subcarrier injection modulation.
<--reason for running over 100% is here
(ii) In no event may the modulation of the carrier exceed 110
percent (82.5 kHz peak deviation).
<-- of course I have seen stations that run MORE (and get fined when caught)
(c) If a limiting or compression amplifier is employed to maintain
modulation levels, precaution must be taken so as not to substantially
alter the dynamic characteristics of programs.
<---(HA!)
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(Of course I find (c) above a joke.....how many FMs have we heard squashed or smashed by its processor???)
A good audio processor will produce consistent audio with music...but of course speech and phone calls will vary the audio but should NOT go over 100%......If you aren't running enough processing and the mod levels between voice and music are greater than 10db on average, you have too little in my opinion. People like to set the volume at one level and dont want to be fidgetting with it back and forth while listening (because they want to be doing something else with their hands).
As to modulation monitors, I find a difference in a number of them on the market today. The reliable 844s are legal but not fast enough to respond to peak readings with todays DSP processors. Some groups try to take advantage of this by squeezing every last % of mod out of the processor they can (heavy clipping, etc) and stay "legal"....but there is a way to stay balanced. Some PDs never get this idea and believe MORE is better or constantly fiddle with the processor...(or use a sister station's settings in another market...when they dont realize the STL, exciter, antenna, etc can change the audio response.....and settings alone are not the answer!)
Last time I listened to KEOM, there was a BIG difference between it and other stations....I had to run the volume quite a bit to get decent level over roadnoise, etc. and then switching back to other stations, DOWN the volume went or else I would loose a good BOSE speaker in the car! BTW my CDs (a lot of them Time Life 70s and 80s) are more consistent with audio, Robert...not to start an argument on audio processing on KEOM....but just a notable fact....I understand the reasoning but feel the audio could be more "leveled" than it is; people are used to it...Yes, even Bob Orban and Frank Foti will agree that women do not like agreesive processing (heck it gives me headaches!) BUT to maintain a decent S/N; and noise is the biggest issue in FM stereo w/mutlipath is a close compete in metro areas, you HAVE to process with maybe 10db or so or AGC (in my humble and professional opinion)...
KZPS (back in 96-01) with the old 8200 and CEC 802D1 playing the same songs sounded great, had plenty of dynamic range and was perfectly legal and was MUCH louder than KEOM was...I constantly had to fiddle with my volume control when changing from one to the other (just my honest and personal opinion).