WHAT'S GOING ON WHEN IT COMES TO HIFI CB?

[543_Dallas]

I offer plenty and have given plenty on this and on other threads, you just don't read and comprehend. These are my opinions expressed here based on just that, opinions and some facts too. That's what a forum is all about, Discussions, opinions, and facts.

You make ignorant statements backed up by name calling.

What's your point here???

I may have done some name calling but this the pot calling the kettle black. You call people morons because you don't like how they sound. There are certain genres that I can't stand the sound of but that doesn't make the artist or anyone that listens to the music a moron.

You know do know some things and I won't deny that. I don't know and understand everything, I never will.

The point I'm trying to make is that some of us like to experiment. Why would you discourage someone from doing so? No one says you have to participate, you don't even have to listen to it. Some wideband guys sound awful and are annoying, but if done right it can sound very good. With the right EQ settings or filters it doesn't have to take up excessive bandwidth.

The best part is it forces people to play by the rules. If they have a crappy antenna system, trashy radio or amplifier they will have a hell of a time keeping RF out of the audio gear. The guy with the clipped limiter driving the hell out of an amplifier will constantly be getting bad audio reports. I know a guy down the street that got into wideband, bought an oscilloscope and his neighbors love it. He had alot of issues in the beginning, but It made him learn the rules and clean up his act.

We discussed it, have exchanged opinions and there were some facts involved. You and I will never see eye to eye on some things but that's OK.

 

[543_Dallas]

100% correct. I worked in the engineering dept. of a commercial radio broadcasting station for 22 years and I have seen some ham/CB stations use a rack FULL of gear, much more than commercial stations, in that quest for "broadcast quality audio" which they THINK they achieved but never really did. There is more to that than frequency response. There is a thing called "presence" which is apparent on properly run broadcast stations (ie those NOT all processed to hell and back) that just cannot be obtained on ham or CB gear. They were never designed for that.

I agree with you. Ameaturs and CBers using the equipment we have can't compare to a broadcast station. We aren't engineers, we are hobbyists. Finals modulated with some basic rack gear can produce a nice sound. I have 2 pieces of rack gear. One is a mic preamp, compressor and a very basic EQ. The other piece is a peak limiter to prevent over modulation. Some guys do go overboard...I'm sure some people think I've gone overboard with the junk I have.

 

[Mustang 131]

Doesn't it force you to get your learn on? Your not going to get hifi with square wave audio into a saturated class c amp.
Most people Ive talked to run scopes or REA to monitor positive and negitive peaks. Hell thats the easy part..follow the rules of AM radio. AM is AM..doesn't matter if it's 770khz or 27.285mhz.
Sorry...Ive heard MUCH better sounding CB stations then Broadcast or ham. That pesky 125% positive peak and bandwidth rule. A flat 15k wide audio with a good multiband processor kicks ass. I've got CD quality gates of people on dx. And with a tad of DSP, they sound like you recorded them in a studio. Ain't that the point.

 

[543_Dallas]

100% correct. I worked in the engineering dept. of a commercial radio broadcasting station for 22 years and I have seen some ham/CB stations use a rack FULL of gear, much more than commercial stations, in that quest for "broadcast quality audio" which they THINK they achieved but never really did. There is more to that than frequency response. There is a thing called "presence" which is apparent on properly run broadcast stations (ie those NOT all processed to hell and back) that just cannot be obtained on ham or CB gear. They were never designed for that.

I know nothing about commercial broadcast so help me understand presence and why an amateur station can't have it. Is this what you are referring to? https://en.m.wikipedia.org/wiki/Presence_(amplification)

If I understand that correctly presence controls are useful when you have multiple mics set up for a couple of news anchors, special guests on the morning radio show, vocals and instrumentals. How does this apply to one person speaking into one microphone?

 

[RatsoW8]

CK nailed it of course and I think W8JI hit the nail on the head (link below) as well when it comes to trying to jam big wide audio into communications gear, i.e., Amateur and CB radios.

http://www.w8ji.com/transmitter_splatter.htm

 

[Captain Kilowatt]

I know nothing about commercial broadcast so help me understand presence and why an amateur station can't have it. Is this what you are referring to? https://en.m.wikipedia.org/wiki/Presence_(amplification)

If I understand that correctly presence controls are useful when you have multiple mics set up for a couple of news anchors, special guests on the morning radio show, vocals and instrumentals. How does this apply to one person speaking into one microphone?

You do have it pretty much. It is hard to describe other that saying that it sounds more as if you listening to a live performance in a proper setting with minimal or no sound reflections echos etc. It is as if you were present during the performance. Yes a single voice into a mike can have presence but it is not as notable as wide bandwidth audio over a greater range. My big chuckle with a lot of HiFi guys claiming they are flat to 15 KHz out is WHY? The human voice contains no, zero, nothing at 15 KHz so why do they feel the need to be that wide if all they are going to do is talk? The human voice contains nothing at 10 KHz and even much lower than that if you really want to get into useful frequencies of the human voice. Typically a womans high pitched scream is about 3 KHz. That's all believe it or not and most of her normal voice peaks out not much more than about 1.2 KHz. If you listen to a single 1.2 KHz tone it is easy to see that it is actually quite high as compared to voice. There are harmonics of course that add to tonal quality and timbre which is part of that "presence" thing however even those do not extend anywhere near as high as most "HiFi" operators claim they can transmit. A properly adjusted transmitter that allows faithful reproduction of 3 KHz will sound just as good as one that allows 15 KHz if all you are doing is transmitting human voice. Complex audio such as music with a wider freq. range and greater dynamic range is a different matter but we are talking voice are we not?

 

[Road Squawker]

W8JI hit the nail on the head (link below) as well when it comes to trying to jam big wide audio into communications gear

http://www.w8ji.com/transmitter_splatter.htm

But, But, But,............ the problem is YOUR receiver,....... just ask the ESSB lids

 

[543_Dallas]

I'm talking about voice and AM. I think a lot of the frustration is because a few people here throw everyone using external gear in the same category.

Most people realize that they can't rival a broadcast station by piping music from YouTube into their CB. They cant even transmit in stereo. They can make it sound good for what it is. When you compare it to the drunk with his mic held up to a crappy stereo, or the noise toy in a hacked up CB it can sound very impressive.

The annoying guys that use external gear will find another way to be annoying if you took it all away from them.

 

[BBB]

Good transmit audio starts with proper microphone selection and has been covered many times over.

Although mic selection is important, obviously, something as simple as where the mic is placed and your relationship to it matters as well. Performing Arts techniques and equipment crossover to Radio often when trying to achieve HiFi audio On-Air.

The following video describes proper mic handling techniques, but there are times when I prefer an isolated mic stand so as to not telegraph floor or desk vibration. A separate remote PTT switch will alleviate mic switching noise.

 

[undertaker]

Man it just cb radio.....

 

[unit_399]

A properly adjusted transmitter that allows faithful reproduction of (up to) 3 KHz will sound just as good as one that allows (up to)15 KHz if all you are doing is transmitting human voice.

This is absolutely, completely, totally, 100% correct. If you're transmitting music, or some other garbage other than voice, than you are in the same barrel as the drunks who key up their mikes in front of their car radio speaker. It makes no difference if it's hi-fi or not. Believe me, you're just as annoying.

- 399

 

[Mustang 131]

Proof is in the gates.

 

[unit_399]

Proof is in the gates.

Prove it. post them.

 

[Captain Kilowatt]

Simply because a transmitter is capable of passing up to 15 KHz (or whatever) does in no way mean it actually IS passing up to 15 KHz when being modulated with spoken voice. THAT is what I have been trying to say all along here. Spoken voice does not contain any frequencies that high that contribute to it being heard. The most faithful reproduction of a human voice would be to have it sound exactly like it does if that person were present talking to you. Look at the frequencies that their voice is comprised of and a lot of HiFi guys will be surprised to see where the roll-off is. They may not admit that their TX does not need to be nearly as wide as they think it needs to be however the proof lies in the frequency components of the human voice and not with how wide the transmitter can handle. My old Heath DX-60B transmitter is wide as a barn door since it has no real roll-off in the mic amp section. I use a Sennheiser MD-421 mic with it and it sounds surperb with no extra audio gear other than a mike preamp. I did use it with a Urie EQ and a audio compressor however it sounds better with just a good mic (the mic has a 5 position bass roll-off filter built in BTW) and no extra processing.

 

[BigKahuna]

I think people forget that our hobby is based on conversation, it's not a hour long radio broadcast. I'd much rather listen to someone who sounds natural than talk to a robot on the air.