EQ Prior to Broadcast

[kfbkfb]

In the early 1970s, one of the monthly audio magazines had an article about FM music broadcasting, (IIRC) "K101" in SF, CA was said to equalize (tone control type adjustments) the audio (I don't know the specifics) prior to sending the audio to the audio processors/limiters and on to the transmitter.

Once a radio station meets the proof of performance FCC requirement, I guess they are free to use bass and/or treble boost (and maybe cut >~13kHz [an vinyl LP mastering guideline]).

Other than this article, I don't recall reading anything about radio stations using (home audio equipment type bass and treble tone controls) on their music, was/(is?) this a common practice?


Kirk Bayne

 

[kevtronics]

It was -- and still is -- very common. This station even prominently showed an equalizer in their TV commercial:

 

[L Chanon Gade]

It was common on AM & FM –but for different reasons.

On AM it was mostly done to keep certain recordings ‘out of the mud”. Records with too much bass were especially a problem in the wideband (Max Brothers) days. Tracks with heavy sustained bass would really lock up the old chains and most listeners would just hear lower volume and a bit more distortion. Here in NYC WABC IIRRC used a Pultec parametric EQ (3 band) and an LA3 to further control dynamics during the dubbing to cart. Album cuts required some modding as they were not really mixed for a mono and narrow band medium. WABC also used a slight (approx 1%) pitchup.

For FM WOR-FM did some additional comping and EQ to heighten the quality difference between FM and the AM competition especially on certain records. When they became Clifton’s 99X in early 1974 it was balls-to-the-walls DAP-squishers. They still had their 1966 General Electric (tubes) board and some of the old cart machines. The noise level was awful, but the kiddies liked it. They pulled it back a bit and added a noise gate in the latter half of 1975.

WPIX Had an early graphic eq (maybe Altec) which I believe they ran in the chain overall. They really boosted the presence band with the inevitable “cart hiss as loud as the music” result. Their tables were real rumblers as well.

Then we had the famous “hamburger grinder” WPLJ with two DAP’s and no stereo link along with sped up records. They went through several processor versions but kept the same sound till mid-’84.

In mid 1979 WYNY (WNBC-FM) made full use of their new last-generation RCA FM transmitter and came up with a highly processed, but very clean and phase-coherent signal. It was almost as compressed as WPLJ but not as brutal. They used a new Optimod and IIRC a couple of Innovonics comps.

FWIW: Although it was much-praised, I never cared for the sound of WHTZ (Z-100) in the 1980’s. It always sounded distorted with intermod distortion from heavy bass. Mr. Shannon brought the same sound (Shannon mush) with him to WPLJ when he came back to New York after his triumphant year in L.A.

All of them went to some form of noise reduction for the carted music by the late 70’s It was usually DBX or Eventide Monstermat/DBX.

This was against the backdrop of nearly none of the NYC FM’s being co-located so there was already some additional EQ-amping added to offset the losses in the telco link to the transmitter.

Personally, I found that –some-- of the out of town FM’s sounded better. Less complex chains and fewer toys to play with.

Today’s all-digital chains have the potential to sound much better, but the old “loudness envy” puts a stop to that every time.



LCG

 

[davideduardo]

In the early 1970s, one of the monthly audio magazines had an article about FM music broadcasting, (IIRC) "K101" in SF, CA was said to equalize (tone control type adjustments) the audio (I don't know the specifics) prior to sending the audio to the audio processors/limiters and on to the transmitter.

Once a radio station meets the proof of performance FCC requirement, I guess they are free to use bass and/or treble boost (and maybe cut >~13kHz [an vinyl LP mastering guideline]).

Other than this article, I don't recall reading anything about radio stations using (home audio equipment type bass and treble tone controls) on their music, was/(is?) this a common practice?

Stations do all kinds of EQ or equivalent. While a graphic equalizer was often used in the past, most EQ today is done via settings in audio processing.

The idea is that a station wants to sound appropriately for its audience, for its music formast and for the transmission system it uses. That may be doing dynamic audio processing to make everything sound in a sonic similar way. So songs or commercials that are not as "bright" may have the higher end dynamically adjusted. Stations with formats that have listeners that like heavy bass may cause the lowest frequencies to be enhanced.

All stations use gear like the Optimod or Omnia to not just level the audio to stay legal, but to enhance the sound spectrum to get the overall sound they want based on the format and desire to sound loud.

Further, in the case of AM, stations may do fixed equalization to make up for the specific frequency response of the transmitter. This was more common in old high level plate modulated rigs or with antennas with narrow High Q bandwidth.

 

[davideduardo]

It was common on AM & FM –but for different reasons.

On AM it was mostly done to keep certain recordings ‘out of the mud”. Records with too much bass were especially a problem in the wideband (Max Brothers) days. Tracks with heavy sustained bass would really lock up the old chains and most listeners would just hear lower volume and a bit more distortion.

Back in the mid to late 60's I used CBS Audimax and Volumax for leveling and compression on my AM stations. When it came out, I added the CBS Dynamic Presence Equalizer to the chain. That unit looked to analyze audio content and, via a very short delay, control it to make sure that what caused the perception of "presence" or clarity was maximized and standardized on everything.

 

[Greg Strickland]

Kirk-

Short answer is yes, broadcasters do change tone of source material prior to broadcast.

As I recall:

Along the way, audio proof of performance rules were removed by the FCC. From the start broadcasters have done whatever they could to make their sound more attractive to an audience. Home audio gear could have been used if professional gear was not available or if the broadcaster was satisfied with home audio gear.

Technically, broadcasters needed to avoid an audio peak level known as 100 percent modulation (broadly speaking) Originally this was done manually with a hand on the audio volume control and an eye on a modulation meter. Soon devices were made that controlled audio volume automatically, now called audio processors. The audio processors evolved, responding to need to improve coverage and ratings, and sometimes in response to human nature.

Eventually the devices could change the tone of the sound, and later they could change what some hear as the amount of stereo.

Practical limits of analog audio implementation resulted in compromises. When it became possible to process in the digital audio domain, broadcasters could change audio sound profoundly. A wide palette of sound signatures is now available to broadcasters by using a modern audio processor.

As context, people who create recorded music also change the sound of audio. It's human nature, we want to make the best impression. Audio sound is a wonderful expression of human creativity, in all music genres.

We live to entertain and attract an audience, and be part of a profitable business.

 

[frankberry]

FM audio processors (peak limiters) have frequency-selective circuits to apply more limiting to high audio frequencies. This is done to avoid excessive high frequency peaks due to the FM pre-emphasis curve.

 

[kfbkfb]

From the early to late 1970s, both CBS (SQ matrix) and Sansui (QS matrix) were promoting their matrix quadraphonic systems as an easy way for FM stereo stations to "go Quad", either by announcing they were playing SQ or QS encoded records and/or by installing SQ or QS encoders and encoding discrete quad content.

I don't recall reading any advice from CBS or Sansui about cutting back on audio processing in order to not damage the matrix quad encoding (which mostly relies on accurately maintaining the phase difference between L and R).

Anyone work at an FM station that was involved with broadcasting matrix quad (did the audio processing mess up the encoding)?

KQ4 - KQIV - Rockin' in Quad: DORREN QUADRAPLEX: THE LONG WAIT

kq4.blogspot.com

Kirk Bayne

 

[davideduardo]

Technically, broadcasters needed to avoid an audio peak level known as 100 percent modulation (broadly speaking) Originally this was done manually with a hand on the audio volume control and an eye on a modulation meter. Soon devices were made that controlled audio volume automatically, now called audio processors. The audio processors evolved, responding to need to improve coverage and ratings, and sometimes in response to human nature.

It's now been about 70 years since all audio control to maintain levels and to prevent over-modulation has been supplemented or replaced by electronic gear.

At first, there were peak limiters intended mostly to prevent extreme loudness and distortion. Programming was distributed by the networks by phone lines and most stations connected studios to transmitter sites with phone lines. Those wire systems did not like excessive levels, and if a level was too low, the noise floor made things unpleasant.

During the 50's we got things like the Level Devil from Harris, and other companies had their competitive products. The "quantum leap" was, of course, the CBS pair of the Audimax and Volumax with the first ones being tube based at the very end of the decade.

By the mid-70's we had multi-band processing which attempted to create loudness while at the same time preventing the "sound" being different from song to song. Of course all prevented over-modulation. And we got a variety of clippers which tried to make stations even louder but sacrificed quality that many of us found objectionable.

Here is what Bob Orban says about audio processing.

History of audio processing

For those unaware, Orban created the Optimod which consolidated multi-band FM processing with a stereo generator and was another "quantum leap" in achieving loudness, consistent levels and a cleaner sound than the prior generation of processors.

 

[Rock 100.7]

I'll throw my .02 in here. Depending on the source I perform a 45-65hz (sometimes more) cut to each and every song that I put in our automation system. I then use a limiter on each track. Everything sounds great. New music is so OVER processed that I find myself having to find a workaround to make it sound better. In my opinion, if you don't have an Omnia 11 or similar $12,000 processor you have to do these things to remain competitive.

 

[Greg Strickland]

Rock 100.7 do you do this in a production room?

 

[Kelly A]

Other than this article, I don't recall reading anything about radio stations using (home audio equipment type bass and treble tone controls) on their music, was/(is?) this a common practice?

In the business, we call it audio processing.

 

[Greg Strickland]

Indeed , just about everyone who has a knob turns it.

I was listening to a YouTube playback of a song and noting the EQ was amateurish. This didn't make sense because the music artist is known to be a perfectionist. Then I remembered the YouTube version was uploaded by some unknown person out there. Who knows, maybe that person is the one who decided to change the EQ, and the original work of the artist sounded fine.

 

[davideduardo]

Indeed , just about everyone who has a knob turns it.

At Hot AC WQII "11-Q" in San Juan many years ago I had a rack panel that had multiple meters, on on the program bus and two attached to pots that regulated the voltage to them. There were also a number of pots labeled "presence" and "density" and terms like that.

Except for the input to the VU meter from the program bus, the rest of the stuff was just connected to a big bundle of wires that disappeared into a cabinet... where they were attached to nothing.

Once I put that in, messing with the actual audio gear stopped. Back channel reports told me that several of the air personalities had found "perfect" settings that made them sound their best.

File under: If it ain't broke, don't fix it.

 

[Mikey Radio]

Here is what Bob Orban says about audio processing.

History of audio processing

For those unaware, Orban created the Optimod which consolidated multi-band FM processing with a stereo generator and was another "quantum leap" in achieving loudness, consistent levels and a cleaner sound than the prior generation of processors.

I didn't realize until reading this that the Optimod-FM had been around since 1975. My first station installed one in the late 80s and the way the Chief Engineer sung its praises, one would've thought it was a relatively new offering. In fact, when they took a lightning hit and had their original Optimod-FM replaced by insurance a few years later, he took the failed unit, replaced the power supply, got it running again and installed it at a club he sometimes DJ'd at on weekends as he liked the processing that much.

At Hot AC WQII "11-Q" in San Juan many years ago I had a rack panel that had multiple meters, on on the program bus and two attached to pots that regulated the voltage to them. There were also a number of pots labeled "presence" and "density" and terms like that.

Except for the input to the VU meter from the program bus, the rest of the stuff was just connected to a big bundle of wires that disappeared into a cabinet... where they were attached to nothing.

Once I put that in, messing with the actual audio gear stopped. Back channel reports told me that several of the air personalities had found "perfect" settings that made them sound their best.

File under: If it ain't broke, don't fix it.

I have a feeling a lot of stations did this. One facility I worked at called theirs a "johnny tweeker" panel, or sometimes a bit more to the point: "@#$% around knobs". As you say, it was effective as the jocks were adjusting them often, explaining how much they appreciated being able to fine tune "their sound" prior to their airshift, etc.

 

[kevtronics]

For those unaware, Orban created the Optimod which consolidated multi-band FM processing with a stereo generator and was another "quantum leap" in achieving loudness, consistent levels and a cleaner sound than the prior generation of processors.

Note that the original Optimod-FM 8000 wasn't actually multiband. It did have a sidechain to handle the FM pre-emphasis curve, but certain kinds of music could still make it punch holes in the audio. It was the pounding bass and sizzling highs of Disco music that made Bob realize that future Optimods needed to be multiband.