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FM Processing Question

G

geekboy2000

Guest
Our Optimod is not in the studio audio chain. It's in a rack with our STL transmitter. At another station I was at, it was in studio in a rack with our compellor and Sat receiver. Is there any reason why we shouldn't bring the Optimod into the studio?
 
In my opinion it’s better to run the processor at the transmitter site. Putting it ahead of the STL often means you can’t run it quite as loud due to STL overshoot. For several years we had our Optimod located in the studio ahead of the STL. After it was moved to the transmitter site, I personally noticed some improvement in the audio.

R

> Our Optimod is not in the studio audio chain. It's in a
> rack with our STL transmitter. At another station I was at,
> it was in studio in a rack with our compellor and Sat
> receiver. Is there any reason why we shouldn't bring the
> Optimod into the studio?
>
 
> Our Optimod is not in the studio audio chain. It's in a
> rack with our STL transmitter. At another station I was at,
> it was in studio in a rack with our compellor and Sat
> receiver. Is there any reason why we shouldn't bring the
> Optimod into the studio?
>

Im no engineer and never played one on TV; but I suspect (from what I know of Audio processing) that the Optimod would be better processing the audio after the STL (meaning have it at the transmitter site) ... but I could be wrong.


<P ID="signature">______________
Program Director/Music Director
X Music Online
The X
Today's Best Music
http://www.xmusiconline.com/</P>
 
> In my opinion it’s better to run the processor at the
> transmitter site. Putting it ahead of the STL often means
> you can’t run it quite as loud due to STL overshoot. For
> several years we had our Optimod located in the studio ahead
> of the STL. After it was moved to the transmitter site, I
> personally noticed some improvement in the audio.
>
> R
>
> > Our Optimod is not in the studio audio chain. It's in a
> > rack with our STL transmitter. At another station I was
> at,
> > it was in studio in a rack with our compellor and Sat
> > receiver. Is there any reason why we shouldn't bring the
> > Optimod into the studio?
> >depends how the STL link is set up.if it is discrete left, right then it would be good to have the processor at the xmtr.but if using composite out it is ok to have it at the studio end...
> compellor can be used to prevent over shoot should that occur....
 
> Our Optimod is not in the studio audio chain. It's in a
> rack with our STL transmitter. At another station I was at,
> it was in studio in a rack with our compellor and Sat
> receiver. Is there any reason why we shouldn't bring the
> Optimod into the studio?
>

Two words, one reason: disc jockeys.
 
LMAO

> >Is there any reason why we shouldn't bring the
> > Optimod into the studio?
> >

> Two words, one reason: disc jockeys.



In days of yesteryear, the Optimods I worked with had a locking door to
all the controls, and even after you unlocked it you needed a greenie to actually adjust the output.

Use of this option will result in a high pitched whine usually originating
in the P.D.'s office.


<P ID="signature">______________
Electricity is really just organized lightning.
~George Carlin</P>
 
In our case it’s Compellor-AD Converter-Digital STL Transmitter from the studio. At the Transmitter site it’s STL Receiver-Digital Input into Optimod. Previously it was Studio-Optimod Analog In-Analog out from Optimod into Digital STL Transmitter.

R

> > >depends how the STL link is set up.if it is discrete
> left, right then it would be good to have the processor at
> the xmtr.but if using composite out it is ok to have it at
> the studio end...
> > compellor can be used to prevent over shoot should that
> occur....
>
 
From the Optimod 8200 and up, they are all password protected from DJ tampering. If a jock was able to get in, blame it on the CE for using an easy password!

R

> Two words, one reason: disc jockeys.
 
> Our Optimod is not in the studio audio chain. It's in a
> rack with our STL transmitter. At another station I was at,
> it was in studio in a rack with our compellor and Sat
> receiver. Is there any reason why we shouldn't bring the
> Optimod into the studio?

If you use one STL and transmit the composite signal to the
transmitter site, you can achieve pretty good results except
for the overshoot problem already mentioned. However, a little
bit of composite processing at the transmitter site can more than
make up for it.

If you use two STL's and transmit L and R to the transmitter site
separately, the Optimod might do more for you at the transmitter site.

In either event, the trick is knowing when there is too much processing.

In the first case, overshoot can manifest itself as ringing [hissing] (sibilance)
and the composite processor will make you louder (of course, at the risk
of listener fatigue).

In the second case, the processing can be split with some compression and
expansion at the studio, and then some limiting at the transmitter site.

This is all an oversimplification of a sticky process that rarely finds many
people in agreement, since "sound" quality is arbitrary. You can measure modulation and spectral content and db of compression, but if it sounds like
crap ...

The fact remains that when you broadcast music that has been recorded and mastered, whether to CD's, vinyl, or tape, there has already been a lot of the
same kinds of processing applied to it. Unfortunately not all music companies master their stuff the same way, so the active circuitry approach in modern processors like the Orban is very adaptive, but takes a lot of playing with to find a setting that treats your stations particular choices in music to the best possible outcome.

The biggest challenge for a music station is getting voice processing in the CR just right so it, too can pass through the chain without the final processing screwing it all up. Or if you do some talk radio, too, that's a royal pain ... or low level phone calls in combo with lazy board operators ... all in all, it's tough to make everything come out perfect.

At least in the analog domain. In the digital domain, I'll yield to some of the younger guys with more hands on experience with the newer Orbans and such.

Ciao!
<P ID="signature">______________
Electricity is really just organized lightning.
~George Carlin</P>
 
Composite Signal Run is the answer//

> Our Optimod is not in the studio audio chain. It's in a
> rack with our STL transmitter. At another station I was at,
> it was in studio in a rack with our compellor and Sat
> receiver. Is there any reason why we shouldn't bring the
> Optimod into the studio?
>
The cable between the Optimod and the STL transmitter needs to be
as short as possible. Composite signals don't work well over long
runs without additional external line drivers.

I believe the Optimod 8400 specs a maximum cable length of 100' of
RG-58 between the Optimod and the STL transmitter.

Its best where it is. If you want it in the studio, you'll need to
move the STL transmitter there too, along with the RF cable run for
that.

There really is little reason to have the Optimod in the studio
unless you love staring at it when you're doing your shift.
 
> From the Optimod 8200 and up, they are all password
> protected from DJ tampering. If a jock was able to get in,
> blame it on the CE for using an easy password!
>
> R
>
> > Two words, one reason: disc jockeys.
>

You are correct. Our entire processing chain is locked up tight and in the XMTR room. With a fiber-optic run and remote control of the Omnia over the network, there's really no reason to have the Omnia in the studio... given the aforementioned loss of composite signal over long distance cable runs. 11 floors, I imagine, counts for a long cable run...
 
> Im no engineer and never played one on TV; but I suspect
> (from what I know of Audio processing) that the Optimod
> would be better processing the audio after the STL (meaning
> have it at the transmitter site) ... but I could be wrong.
>
Depends a lot on where the transmitter is, how far away it is, etc.

I have a 25 mile path to one FM, hence I use a discrete (l and R) STL feed into the Optimod at the transmitting site. But I also have a booster (for a different station, of course) at that site, which I feed by composite STL from the second output of my Omnia. This keeps the booster signal sounding like the main channel signal.

I've been to a site in southern WV that is on a 3,000 foot mountain. Takes a 4WD drive up a narrow, switch-back road to get to it. With a site like that I would want the audio processor back at the studio.
 
I agree (and Bob Orban, et all) would agree....if you have overshoot issues with the STL, its better to place the processor at the tower site...ALSO if you have discrete STL (L/R) on the RF, that usually is a DSP6000 or a Harris Starlink unless you run different STL freqs for the L and R...in the single STL case, I never liked putting a processor ahead of the DSP6000; the Harris is ok but not all the time. I had several FM rimshots...I preferred the processor at the tower site so it would auto switch the audio path...if the T1 hiccupped which had AES audio, it went to the STL analog audio...and no loss of audio...
I loved it ;) and the station sounded better...the VP of Egr (who was an ASS) did not want to put it there...he didnt like switching supplies...(REALLY!)..but the change in the STL path required it to go there...and a reset lead from the Rmt Control takes care of any lockups...the current engineer there said he never has had that issue...just put a Compellor on the STL feeds and no problems

> In my opinion it’s better to run the processor at the
> transmitter site. Putting it ahead of the STL often means
> you can’t run it quite as loud due to STL overshoot. For
> several years we had our Optimod located in the studio ahead
> of the STL. After it was moved to the transmitter site, I
> personally noticed some improvement in the audio.
>
> R
>
> > Our Optimod is not in the studio audio chain. It's in a
> > rack with our STL transmitter. At another station I was
> at,
> > it was in studio in a rack with our compellor and Sat
> > receiver. Is there any reason why we shouldn't bring the
> > Optimod into the studio?
> >
>
 
> If you use two STL's and transmit L and R to the transmitter
> site
> separately, the Optimod might do more for you at the
> transmitter site.

Honest question: Why would you do this? Why not use a digital encoder/decoder combo and just use 1 STL. Do a little ALC at the studio side to prevent clipping and then have the Optimod sit at the transmitter site.<P ID="signature">______________
If you put your mind to it, you can accomplish anything...</P>
 
Re: Composite Signal Run is the answer//

> There really is little reason to have the Optimod in the
> studio
> unless you love staring at it when you're doing your shift.

Maybe he has a discrete STL and it is there for the reason
of generating stereo. If he has a composite then it could
be moved to the studio end BUT I have seen a 2db drop in
loudness on most composite STLs just due to the
fact that most STLs have some bounce or inherent loss or
noise which the processor can overcome if placed at the
transmitter.
 
Re: Composite Signal Run is the answer//

> Maybe he has a discrete STL and it is there for the reason
> of generating stereo. If he has a composite then it could
> be moved to the studio end BUT I have seen a 2db drop in
> loudness on most composite STLs just due to the
> fact that most STLs have some bounce or inherent loss or
> noise which the processor can overcome if placed at the
> transmitter.

Read the original post. It wasn't a question of it being at
the transmitter site, but the poster was asking why in the
rack room at the studio location - as opposed to being in the actual
broadcast studio itself.

By the description, its apparent he's using a composite STL..


>
 
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