max pro I & audio level

Share your experience regarding radio transmitters and broadcasting with other users!

Moderators: Sir Nigel, Nina, pcs, 5r, phpBB2 - Administrators

Post Reply
Dan Anka
New registered user
New registered user
Posts: 3
Joined: Sun Mar 24, 2002 1:00 am

Post by Dan Anka »

Does anyone know if turning up the audio level trimmer has any advantage over just a higher level of audio into the transmitter in the first place? (as far as avoid high end distortion)
StormiNorm

Post by StormiNorm »

A more definitive answer could be provided,if you were to provide a few more details such as:

1)are you running a stereo generator and or a limiter?
2)the mode position of J1
3)by what means or what indication that has led you to descern a high frequency roll off?

Provide the answer to those questions,then it can then be determined the exact nature of the problem,and relevant suggestions made to find a correction.

And of course if you turn up the modulation level too high you will exceed the max deviation of +/- 75kHZ

<font size=-1>[ This Message was edited by: StormiNorm on 2002-06-10 19:22 ]</font>
StormiNorm

Post by StormiNorm »

Were you able to find the answers to the enquires that i made???
StormiNorm

Post by StormiNorm »

On 2002-03-24 10:25, Dan Anka wrote:
Does anyone know if turning up the audio level trimmer has any advantage over just a higher level of audio into the transmitter in the first place? (as far as avoid high end distortion)

There has been 227 views on this topic,so obviously there appears to be some interest for whatever reason...Is there a problem???if there is,or if there exists some "dark areas"(no pun intended)why not let us all engage in some productive and meaningfull discussion..i am not the only contributeing member in this forum,and i am not just gonna sit here and waste my time and participate in a "Frequently Answered Questions" forum..I do have a few comments and suggestions that i can offer that is very relevant to the above message in regards to the M1P Or any other PLL for that matter.I am not here to prove to anyone,or feel a need to prove to anyone the depth of my knowledge...i will let my words speak for itself...I am here to share knowledge,experience,make friends,have fun and enjoy life and LPFM to the maximium.So as far as i am concerned this topic is closed,as far as my submitting my views on this topic...Active and interractive participation is one way of knowing if,the knowledge base is helping to address any "gray areas" or provideing solutions that are well understood and practical..Please dont be afraid to ask questions..What i am aaginst is questions of a "staged scenario".I personally donot like staged events,epecially in this theatre of operation...As far as i am concerned,there is a valid reason for any questions asked....The ball is in your court.
Dan Anka
New registered user
New registered user
Posts: 3
Joined: Sun Mar 24, 2002 1:00 am

Post by Dan Anka »

I bought the Ultramizer Pro, DSP1400, by Behringer, and after some configuration, and also tweaking the level trimmer in the max pro xmtr, I finally was able to obtain a VERY loud and good quality sound. Sounds just as clear, high, and loud as everything else on the dial. Thanks for replying, sorry I didn't get back to you on the boards faster.
StormiNorm

Post by StormiNorm »

Alrighty then..Stay Kool
StormiNorm

Post by StormiNorm »






From: "jaycifer_1" <jay@f...>
Date: Mon Jun 24, 2002 8:18 pm
Subject: HELP! Ya know I need someone!






I'm having problems with my max-pro. It sounds like I'm lacking fidelity
in stereo mode. Maybe I'm trippin'. But with the mono there is definitely
a problem! I think it may lie in my RCA connection. When both sides are
connected there is a strong humming sound. When I disconnect one side
the humming is not there. What the hell is wrong? I hope I didn't ruin
it!

StormiNorm

Post by StormiNorm »

From : "EJ2K" > : "Pirate Radio List" To : "Pirate Radio t" Subject : Radio > More on compression? How about "perceived sound" and "Listener Fatigue"! Date : Tue, 19 Jun 2001 16:30:37 -0400
Sent: Tuesday, June 19, 2001 9:59 AM Subject: Radio > More on compression? > Pirate Radio List - > > I read Norm B's exelent posts on audio/compression (Thanks Norm!) > Is anyone familiar with a good source of additional info on propper > compression for FM (like the best gain settings without that "squashed" > sound?). Pardon my absence folks... I've been absolutely *buried* by multiple projects and my inbox it exploding! I know what sounds good (in MY opinion) for most "commercial" processing, however, it usually contradicts what a Program Director considers to sound "good" (105% modulation with 75 dB of processing). When you're talking about compressors or limiters which have no variable adjustments for time constants, ratios, etc. (what I call "fixed-state" vs "variable-state"), it's pretty much a "trial and error" thing. I'd just run them in a "conservative" manner by keeping the levels on the lower side. Especially true of "fixed state" limiters moreso than compressors as they can wreak more havoc on a waveform. Let the compressor do most of the gain riding, but try not to squash the signal. The limiter should just control the peaks and not be used to dramatically alter the signal. For variable-state processing, keep the attack and release times slower on the compressor and set the peak limiter fast, but only let it limit under 5-10 dB or so. Otherwise, the highs will punch holes and a lot of bass will cause pumping or a "ripsawing" effect on the waveform, which will sound "grinding" and cause increased listener fatigue. Always allow your audio to "relax" a bit instead of being "nailed to the zero" all the time. SOUND PERCEPTION AND LISTENER FATIGUE What is "listener fatigue"? I'll try to keep the explanation of human sensory system simply, if that's possible... The ears have "spacial" (or "directional") perception of "left to right" in the same way the eyes percieve "left and right". Both also has a "dynamic" perception - "soft to loud" and "dim to bright" respectively - something is perceived as "brighter" or "louder" as the amplitude of the stimuli (light source/speakers) is increased. The ears also have a somewhat limited "quad-directional" perception of "front to back" as well, just as the eyes have "peripheral vision" beyond that which is near to far. Your brain is used to, and expects, variations in the levels of stimuli it perceives (dynamic range). The brain uses this for the "startle reflex" and for "directional imaging" (ie, your brain can determine where a certain sound originates by it's position in the soundfield - even in complete darkness). If I hear a "CLUNK" behind me and to my left, my brain tries to determine what it was. The brain notes the area of the field that it occured in (left, rear) and that is instantly mixed with the visual perception of the "environment" and the brain deduces that the "KLUNK" was Karen adjusting the recliner. This is an example of a "normal" environmental perception. When the brain is confronted with a stimulus that is limited in dynamic and spatial range (like FM radio), it "seeks" for those normal variations in amplitude but doesn't find it. It then compensates by supressing the stimulus- the ear's equivalent of squinting in bright sun. When you are wearing headphones for an extended period, it seems as if the headphones are losing loudness and you have to keep inching the volume up. The ear/brain continues to rebel against this unvarying amplitude by constantly recompensating. After a while, this results in "ear strain" If allowed to continue for long periods, a "ringing headache" will eventually develop (ever had one of those after a concert??). Most people subconsciously react to this fatigue by eliminating the offensive soundfield (by turning off the radio). They don't know why, but they become "tired of listening" sometimes in as little as 15 minutes, depending on how loud the offensive soundfield is. If the TV is playing in the background, after a while the brain tends to ignore it as you do other things, such as typing an email. You still HEAR the TV, but the brain has "disconnected" it from your environment and stops "processing" the information from it. You're hearing it but not "listening" to it... Hmmm... I guess that's what was happening as a kid... it wasn't *my fault* that I wasn't listening, my brain simply "supressed" their input! :-) So, how a sound looks on a meter is much different than how the ear and brain perceive it It's expecting sounds to vary in amplitude and space. What you hear in your headphones is not only limited in dynamics, but in space as well. The brain fights to generate a proper "image" of the environment, but there's not enough "peripheral" "front to back" elements present and the brain begins straining to find it. I hope that made some kind of sense to somebody else... Ed
================================

I just thought i would share this bit of archived info with you all...this is experience talking...real world applied interpretation...Wickid i might add.

Norm B

"Man is most nearly himself when he achieves the seriousness of a child at play" by Heraclitus
StormiNorm

Post by StormiNorm »

Also after one has " Fireeeed" it up,or the fact that one has become "comfortably numb" enhances the relative state of one's perception of what sounds good...This is one area of broadcasting that in my view,where no test equipment,other than a modulation meter used to verify that one is not over-deviateing,is of any real use,The remainder is a sense of perception of the human brain,the flavour of the music being rendered,etc.etc.


One of the cardinal sins of the un-informed LPFM Operator is that of overdriveing the audio somewhere along the chain,i guess they believe that if they turn it up and they sound louder in the studio,then they will also sound louder over the air...nope not necessarily so..they might just be splaterring so badly and dont even know it.

Another common error that i have seen some folks execute is that of monitoreing the audio output,under near field radiation..Walk or drive a couple blocks(miles) down the road,and have your "cellulite" phone with you(hands free operation..dont let "Babylon" (police) give you a ticket.)and have someone at the studio do a bit of tweaking here and there,throughout the various critical audio areas,especially if you are useing a limiter and running some "Komppression"(no Sir Lancelot..not that form of "cummppression")

Find a local flame-thrower,that you know is abiding by the Books and the rules,and use that station as a comparision check,and re-adjust your sound accordingly.Let your ears be the meter.

Norm B
Post Reply