Hi Nate,
> > re: An advocate for a little audio compression.
> Nate Duehr <n...@...> wrote:
> You're a brave man to say it, Skipp.
> Here's my problem with it. Let's just say there's a very
> large linked repeater system that decided MANY years ago
> that they could "fix" the incoming audio from their IRLP
> link from BADLY CONFIGURED IRLP NODES by adding a commercial
> compressor-limiter in-line.
Depends on what's coming out of the IRLP source... it's not
the job of a limiter/compressor to improve already over crunched
bad audio. My "advocate for a little audio compression"
statement is meant to deal with helping soft talking, non
booming (higher pitch) voice types. The specific case I
referenced was a simple repeater with one half-duplex link
radio.
If non professional hams with bad ears and opinions are going
to hose up their audio with excessive compression/limiting...
there's probably not a lot you can say or do about it if they're
not willing to listen, learn and apply the knowledge.
> I won't say who or where, since I like the folks running
> it and have ZERO beefs with them. I just need to use them
> as an example of where compression/limiting is BAD NEWS.
> However, let's also just say that I've called them from
> MULTIPLE IRLP nodes I've set up PERFECTLY with a service
> monitor and swept for audio response, and they ALWAYS
> complain about whatever it is they're hearing on their
> end -- after their compressor-limiter.
> Hey guess what folks. The audio left here JUST FINE...
> someone on that end decided to muck around with it. Not
> much I can do about that.
If you were close to them... you could offer to have a look
at the levels and crank the controls back down to a more
realistic value. But when things progress to this level... you
very often have to deal with some type of control freak who's
going to crank the knob back up after you and Elvis have left
the building.
> What does this phenomenon actually lead to? I don't know.
In many cases... people turning the radios volume knob off or
the frequency selector to another location. Possibly switching
from Pepsi to Coke or another bad thing?
> Maybe an idea below...
> I know my nodes are done right, and I know they have a LOT
> of other nodes connected to them that sound like ass so they
> tried to fix it.
("sound like a$$"... a Southpark reference...)
> But, instead of asking those folks to fix their nodes, they
> tried a fix on their end, and broke things for those of us
> sending proper levels and audio.
It's more likely a Repeater Owner Operator error...
> If they'd put in a way to TURN IT OFF, they'd hear what a
> properly set up IRLP node is supposed to sound like.
Only takes a decent tape or mp3 audio file recorder playback to
provide the proof. But it can take time to retell the story of
"The Emperor's New Clothes".
http://en.wikipedia.org/wiki/The_Emperor%27s_New_Clothes
> Do I care? Not really. But the experience of that problem
> over the years, has just entrenched me further in the "what
> comes in is what goes out" camp.
One or a few bad examples spoils your entire apple cart...
> Do I realize that the vast majority of folks setting up IRLP
> nodes don't bother setting levels CORRECTLY to a network
> standard? Oh heck, yes. I rant about that at least once
> a year on the IRLP list... to mostly deaf ears.
A lot of Amateurs lack the resources of a decent Communications
Service Monitor, some experience or a knowledgeable friend offering
to help. The human ear is not a linear device so most cases
of setting levels by perceived audio value are not good.
> So I say, sure... compress away on a local repeater only.
> But please keep the compressed audio the hell away from
> outbound links to others... and away from the incoming link
> audio too. And always provide a way for the USERS to turn
> it off, just to see if it's having a bad effect.
> Seems reasonable, doesn't it?
Yes and no... each case is different and how each system
operates is different. How many places your audio is going
with how many times it's man-handled by people with/or hardware
and equipment.
> I think that's a fair opinion to all.
> Compress the snot out of local traffic if you want... but
> please send the rest of us something that sounds like what
> your users put in out any links, especially IP-based ones.
Again, how I would and do set up IP-Based Systems vary in
each case and compressing the snot out of any audio is not
good news. When you have or use a Non-Dynamic AGC-Based Hard
Limiter it seems much easier to stay out of the over compressed
crappy audio zone.
> Otherwise you run the risk of really bugging those of us
> who DID set levels and test audio, by creating a new problem
> the users on the far end think is OUR problem.
> What do you think Skipp? Is that a fair point to make? Links
> to other people's systems shouldn't include compression.
I think you're focused on the wrong issue... I run Multi-Hub
and Chained Repeater Links with well thought out audio levels
and they do include a very modest amount of limiting type
compression... and they sound great. You probably need to vent
a stronger opinion against bad audio level choices made by the
over casual repeater system/equipment owner/operator(s).
> Now... the reality is... some repeaters do it anyway... hard
> to stop it from going out. I can almost always tell ya when
> someone's on a MODERN (not MICOR) Motorola repeater by listening
> to their audio coming out of my IRLP node(s). In fact, with
> the audio set up correctly on an IRLP node, it's downright
> easy to tell there's a Bat-Wing somewhere on the other end
> of the link.
There are other traits beside levels, which help many
experienced radio types tell the difference between a Motorola
type repeater/receiver audio versus other mfgrs. But keep
in mind it's fairly easy to make a non Motorhead Repeaters
and Receivers have similar to Motorola audio. It's a combination
of actual hardware/circuit traits effecting what the users hear.
> Nate Duehr, WY0X
> n...@...
I'd like to say I've done a lot of the proper homework... and
I suspect few users can tell the brand name of the majority
of our repeaters from the on-air audio. And there's a fairly
large mix of many different equipment brands...
cheers,
skipp
