Subject:Delay Distortion added to commercials?

Posted by: musicvid10

Date:1/20/2010 9:32:25 AM

I did a lot of analog audio and some rf work back in the seventies.

It's pretty common knowledge that tv advertisers add unnatural amounts of compression, add sound effects and boost frequencies in the "danger" range (1-4KHz) in order to make us look up involuntarily when one of their monstrosities comes on. No one denies this.

Here's my theory: I swear when most commercials come on I hear phase delay distortion at >=1Khz. It is pronounced in comparison to "normal" program audio. It is truly annoying and when used with percussion or noise effects and high-pitched voiceovers has me reaching for the mute button like a fire alarm had gone off.

Here's my question: Do any of you pros know of a utility to detect and quantify group audio delay without a dry reference? I found reference to a lab measurement program, but want to know if there is anything free that I could run some tests and perhaps post them on the net.

MTIA

Subject:RE: Delay Distortion added to commercials?

Reply by: jbolley

Date:1/20/2010 1:57:25 PM

I don't know of such a product. You could try to make a spot then affect it like you are hearing, then compare with TV ads.
I've made spots and shows that have aired and know nothing about what you're suggesting. Is there any chance you're trying to decode the TV signal with dolby or dts? Perhaps the program is encoded and the commercials are not...
Jesse

Subject:RE: Delay Distortion added to commercials?

Reply by: plasmavideo

Date:1/22/2010 1:39:10 PM

Interesting what you are hearing.

As mentioned it may have something to do with the fact that the commercials are in stereo and programming in 5.1?

We have heard some strange problems like that from some network feeds when the center channel stream and the stereo stream were slightly out of time with each other, and the dolby encoder tries to make 5.1 out of stereo. The generated center channel is just a bit out of time with the L/R and can cause a phase issue,

We use some pretty sophisticated loudness controllers in attempting to dampen the annoyance factor. I wonder if you are hearing an artifact of a device such as this?

Are you hearing it on one particular station, or everyone?

Subject:RE: Delay Distortion added to commercials?

Reply by: musicvid10

Date:1/22/2010 10:16:10 PM

It's the same off of two tuners (a Samsung and a ChannelMaster). Both using the stereo outs, not the optical or spdif. OTA broadcasts, on all networks. The programming sounds fine. The group delay on most commercials is rather pronounced, to my ears anyway. I took acoustics courses in college. The advertisers don't make any attempt to conceal the enharmonics from their crackling, slurping, swishing, gargling, snoring, beatboxing, whooshing, sniffling and simpering. Drives me up a wall.

Subject:RE: Delay Distortion added to commercials?

Reply by: musicvid10

Date:1/24/2010 7:03:19 PM

Update:

There is at least one network program using this same dubious practice. It is "Cold Case" on CBS.

Intolerable.

Subject:RE: Delay Distortion added to commercials?

Reply by: plasmavideo

Date:1/25/2010 8:55:18 AM

"The advertisers don't make any attempt to conceal the enharmonics from their crackling, slurping, swishing, gargling, snoring, beatboxing, whooshing, sniffling and simpering. Drives me up a wall."

What a description! I love it.

Interestingly, when I worked in radio, first as a DJ, the more wheezing, pumping, snorting, etc we could get out of the on air processing, the better! As I moved into a combo of on air and enginering, I tempered my tastes quite a bit and tried all the tricks for getting loud but proud - it was always hard to find the best blend of loudness without artifacts . However, the program directors still wanted it louder - artifacts be dammed, so on to the latest and greatest compressors, limiters, composite brick wall clippers, etc.

When I moved over to TV the opposite was true at first. The dynamic range of programs far exceded those of the commercials, and we had to start decreasing the dynamic range of programs so they would not get swallowed alive by the commercials. Not a day would go by without a dozen phone calls about "your loud commercials". Advertisers never seemed to get the idea that people would get so turned off by the practice that they would avoid that advertiser's products (instead of calling attention to themselves in a positive manner, they created the opposite effect).

So next we tried lowering the levels on the commercial playout tape decks about 6 db below the ones used for programming. That still wasn't enough, and commercials that did not have brick wall audio came out effectively lower perceived level than the ones adjacent to them, and the advertisers complained that THEIR spots were being lost in the shuffle. So next, I started processing the playout from the commercial machines in a seperate audio chain from programming.

Then came digital, where everything was being played out locally from the same servers. Then I installed seperate processors on the inputs to the servers, so the digitized audio on spots from tape was processed seperately on the commercial and programming ingest channels. But then spots began coming in as files, and other than doing some work in post production on each one, we were at the mercy of the agencies again.

Then with DTV everything went from 1 BNC and 2 XLRs to AES and other audio streams - some inbedded audio, some not - some stereo, some 5.1 etc, etc, etc. with even more dynamic range. Then there was dialnorm, then there was this, that, and the other - ARGGHHHH! Then some TVs and DTV converter boxes behaved differently. Some cable companies reprocessed the audio and some decoded and recoded it differently. Then the loudness wars started on TV. "How come they are louder on cable than us" etc . . .

Finally we've found some very intelligent digital processing that works well on both stereo and Dolby 5.1 for the main on-air signal chain, but we still have to do preprocessing on ingested commercials and local news to try to keep everyone happy. Trying to keep 5,1 and stereo coexisting for equal loudness across multiple sources and destinations is a real treat.

Oh, did I mention trying to equalize audio for the consumer for both their 54 inch plasmas in the den with 5.1 and thunderous subwoofers, and their little 15 inch LCD in the kitchen with 2 3 inch stereo speakers? (" how come your audio sounds louder than WWXX in the den, but I can barely hear you in the kitchen?")

On a side note, rip the audio off of a contemporary music CD, take it into SF and look at the waveform! It's virtually a flatline at 100%. In the car I have some of my old timer's CDs I listen to (Bad Company, Blue Oyster Cult, Boston, Kansas, etc and yes, even some dance and disco stuff - "Burn Baby Burn" ), and if I pop Hannah Montana or the Jonas Brother's stuff into the car player for my daughter, it blows me out of the seat. What does amaze me is that on some of the tracks, the mastering is done so well that even with the crushed audio, there is little apparent perceived distortion and even some perceived dynamic range.


EDIT: Oh yeah, one of the other ad tricks is to equalize the audio with a huge midrange screech boost so it stands out. Those are hard to deal with without our intervention before they hit the servers. Trouble with all this is that a lot of commercial arrive automatically via satellite or internet delivery and are transferred into the servers automatically. We do have in place now software that can automatically analyze the peak, average and RMS levels and process the audio within these files before it is converted to our server playout format and transferred to the servers.

Sorry to be so longwinded. . . .