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- March 8, 2011 at 6:06 am #7682
Increasing bass boost doesn’t boost the bass much, but sounds like you rolled off the treble?
Increasing treble boost doesn’t boost the treble much, but sounds like you reduced the bass boost?Increasing bass boost doesn’t boost the bass much, but sounds like you rolled off the treble?
Increasing treble boost doesn’t boost the treble much, but sounds like you reduced the bass boost?
Heavy audio limiting can cause strange side effects.If you don’t have the luxury of using a high-end multi-band equalizer/limiter, you may experience these strange effects. With heavy compression/limiting, you are always running at a constant peak volume level. So, if you fiddle with the equalizer to boost any particular frequency range, the other frequency ranges will diminish relative to the boosted range.
This is just food for thought.
March 8, 2011 at 6:47 am #21114Carl Blare
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Total posts : 45366Yes, PhilB, that experience comes as a surprise to the newbie first trying to achieve the magic sound, which for a lot of people is juke box thumpy bass.
You have reminded me of the days when hi-fi amps had a “loudness” control which somewhat lowered the mid-range while boosting the low bass and the upper highs, which I think was meant only for low level listening, but many people preferred that sound turned loud, and if it was put to a transmitter it was a lot like what you’ve described.
March 8, 2011 at 11:09 am #21116RFBurns
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Total posts : 45366Trying to cram too much frequency response through a RF carrier with limited frequency response capability…your gonna get not only odd side effects, but over-deviation on the FM and heavy clipping on AM.
Remember, even the type accepted FM exciters cant go beyond a 75 to 85 percent carrier deviation and then simply distorts. Receivers are built from the factory limited to about 80Khz and everything else beyond that point of deviation is simply cut off and not heard.
In AM your even more limited unless you open up an AM Stereo receiver’s wide bandwidth mode which kicks out that bandwidth response from the itty bitty 5-7Khz NRSC (YUCK!!) to the nice and wide full 10Khz (C-QUAM).
RFB
March 10, 2011 at 12:40 am #21166gmcjetpilot
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Total posts : 45366I would say getting EQ and limiter and compression is not exotic or expensive. A not very powerful PC or laptop with enough power to run win-amp and stereo tools (freeware), I found to be a life saver. Some transmitters seem to be way more robust in what you feed them. Other transmitters just sound awful with some audio sources. The Talking House AM transmitter has a “limiter” in the audio input signal path. I looked up the part number for that IC chip, regardless it does a pretty poor at limiting. Long story short it’s sensitive to the audio source. If you under-drive the modulation to assure no clipping you get clear but weak sound. Pushing up the modulation and audio bandwidth, with the computer and audio software I get a richer sound with out distortion.
I can do this with out “stereo tools”, just EQ and volume, but it takes some compromise. If the source (internet radio, MP3) changes from soft music to loud and dynamic, “stereo tools” keeps it in check and adds just a little more “loudness”, dynamics and fuller freq range. It was tedious to learn the settings and see what they did. However “stereo tools has some canned settings to choose. I would put my audio up with any of the local stations. There are other for free programs you can buy or even try as demos. I highly recommend messing with these.
If you want hardware limiter compressors they are out there for not that much money. There are some bare compression/limiter circuit boards on eBay you could hide inside the same box with the transmitter. There are schematics you can DIY, and last rack component type audio processors for not that much money used. Personally the software ones are pretty good, when the software is free.
March 10, 2011 at 12:44 am #21169RFBurns
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Total posts : 45366I would say getting EQ and limiter and compression is not exotic or expensive.
I agree. For a mere 20 to 30 dollars more over the price of a typical Part 15 compliant transmitter, you can have a really good comp/limit/gate unit that will do the job just fine. And then focus more investment on the transmitter antenna and ground systems, as well as expansion of that delivery system to cover more than the so called “200 feet” as a lot tend to throw around in all discussion boards. Though we know with MW, 200 feet does not apply in reality…for FM..75 to 150 is more like it.
My point is that going over some of the pictures of studio stuff thrown on the web in a Part 15 setup…I find it not only totally ridiculous..but totally useless when all that investment gets shoved into a single rack and there sits this tiny box with a stick on it outside barely pushing 1/4 mile or so…and that is it!
Sort of bringing on board a row boat everything including the kitchen sink and there is no where to sit and row row row the boat…sink it past the waterline…..
RFB
March 10, 2011 at 12:09 pm #21195RFBurns
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Total posts : 45366And hey, I’m not trying to disrespect you! I just disagree.
See, this is what I fully support..agree to disagree and we move on with the subject at hand. However I have had to deal with beating the dead horse to death on a couple of instances in other threads…here I have not so no worries. We’re good.
Valid points either way it’s looked at. One can have pure clean sound at low volume (weak signal) and one can have noisy distorted clipping junk at high volume (power house).
Why I say what I say about big piles in front of a tiny wheel barrel:
I just believe in putting the money where it really counts for the station in what makes it a reality…the transmitter/s and antenna systems first then throw in the works for audio..which is how I did my stations.
My setup has the following, starting with the transmission system:
As seen on The Low Power Hour site,,,the CC AM system and the Ramsey FMs consisting of:
1 LPB TX 2-20 CC transmitter (C-Cuff C-QUAM exciter)
1 LPB AM 25 CC transmitter (C-Cuff C-QUAM exciter)
1 ASMAX-1 C-QUAM exciter (backup to both LPB’s)
2 LPB TCU-30 transmitter couplers (1 as backup)
1 Ramsey FM 100
1 Ramsey FM 100B
7 8′ ground rods (4 on 219 stick, 3 on CC system)15.219 Antenna
1- 3 meter 1/2 inch diameter copper pipe bottom loaded, tapped and tuned w/540pF variable mounted on a 2 foot tall 3 inch pole with 4 8ft ground rods and ground radial system of 20 15 foot long ground radials extended in a complete 360* circle. (backup 219 to main 221). Auto peak tuning and sensing circuitry, side lighting day/night function and complete RF bypassing on all lines in/out. Wx proof box and integral de-icing/temperature compensation.Audio chain (not counting automation systems in front)
3 R.S. 6 channel mixers and 2 RS 5 channel mixers (rat shacks)
1 32×32 Computer Concepts router/switcher
2 DBX 1BX Dynamic Processors (1 feeds AM, 2nd feeds FM via router)
1 Sigma SVS-1 Volume Stabalizer (for external inputs/router selectable)
1 Phonic PCL 3200 comp/limit/gate (FM feed)
1 Sampson S-Com Plus comp/limit/gate (AM feed)
1 Sony ST-JX220A receiver (studio off air monitor AM stereo)
1 Sony STR-D315 receiver/amp (studio monitor amp/off air FM monitor)
2 Altec Lansing 1200 studio reference speakers (these are huge!)
1 EV 400 studio mic (my mic)
4 R.S. cheapo aux mics (interviews etc)RF/TX monitoring/measurement:
1 HP 8590A spectrum analzyer
1 Motorola R2012D communication analyzerAutomation systems/computers:
3 custom built 3.2Ghz 2Gb DDR 350Gb HD mainframes (2 WinVista-1Linux)
2 5Tb Raid arrays
2 SAM broadcaster automation (net and backup)
1 Maestro v2 automation package (terrestrial)Much of this gear is bought from auctions and online auction sites like ebay. Custom computers are industrial rack mounted units salvaged from old Maestro system replaced with newer versions at local station (got lucky with those).
Given the AM TX system’s cost comparison of yesteryear and cost on the audio stuff alone (recent stuff) at today’s pricing…the most investment was made on the TX systems and for the custom built 219 antenna system and associated extras in that plus design and test time involved.
Other than that…I dont have any elaborate EQ or multi-band processing or modulation punchers. Fidelity is more priority to me than blasting listeners ears with loudness excess.
That’s about it. Oh there are the spare parts and work bench full of stuff and of course..the “X” closet filled with…(COUGH) RF power stuff.
RFB
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The views and opinions expressed here in this reply do not necessarily represent the views and opinions of Part 15.us, its management, owners, staff, the birds and the bees, jelly beans and pumpkin seeds, apples and pineapples, oranges and lemons, or any other member of Part 15.us information-idea-opinion exchange forums and blogs. The reply represents ONLY the author’s and do not necessarily declare as the be all end all….read at your own discretion!!March 10, 2011 at 12:55 pm #21197RichPowers
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Total posts : 45366……………. …… …Other than that…I dont have any elaborate EQ or multi-band processing or modulation punchers….
Yeah, that set up you got ain’t elaborate at all! (sarcasm).
I already had seen your CC transmitter pictures as I listened to the show.
I got curious about the EV 400 mic you use, but couldn’t find it in a search. By the way, it wasn’t till you listed your gear that I recalled I had one of the same DBX units in my original Part15 set-up, there was a run of praise about those units on the old forums for awhile, and it had influenced me to get one.I just believe in putting the money where it really counts for the station in what makes it a reality…the transmitter/s and antenna systems first then throw in the works for audio..which is how I did my stations.
That’s a far cry from the way you put it in your previous statement.. but your phrasing this time makes perfect sense… And of course I’ve been doing it the very opposite way!
But fortunate for me, my senseless ways in projects often eventually result to effective results. So I guess It’ll be ok.March 11, 2011 at 3:52 pm #21233RFBurns
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Total posts : 45366Well keep in mind much of that gear is stuff I had on hand from years back! I do mean years back! Back to the era of first diving into CC broadcasting in 73. Still quite useful today, morphed from what once was used in the stereo rack to use in the studio. In 73, that dbx 1bx unit was the ONLY processing I had too.
The EV is a typo. Its an AKG 4000 studio mic from the same 70’s era. Phantom powered with the pattern switch. Dunno why I said EV…maybe because it reminds me of an EV mic I used to sit in front of during my actual paid radio DJ days. But it is an AKG 4000. Closest comparison is its newer cousin the AKG 4000 C, except the C has a round body. Mine has the narrow “wedge” type body, similar to the newer AKG C214.
I can tell you what items there are of recent purchase in the audio chain…recent meaning within the last 15 years. Both comp/limit/gate units and the Sony STR-D315 and the Sigma volume leveler. Other than that, the rest of the audio chain are items already on hand. So to specify the actual audio chain processing..it is:
2 DBX 1BX Dynamic Processors (1 feeds AM, 2nd feeds FM via router)
1 Sigma SVS-1 Volume Stabalizer (for external inputs/router selectable)
1 Phonic PCL 3200 comp/limit/gate (FM feed)
1 Sampson S-Com Plus comp/limit/gate (AM feed)I don’t count the computers and automation as they are programing sources, not audio chain equipment. But I threw those in there to give you the complete studio setup.
In all, the most investment went to rounding up the LPB stuff and building the 219 antenna system and its transmitter. In actual investment, that comes to around 2.5 grand, mostly in the LPB gear. If we went by today’s dollars, that would be about double on the LPB gear alone. Let’s not also forget about the spectrum analyzer and the communication monitor, vital engineering tools to RF transmission and thus should be counted as transmitter system investment. No different from investing in an AM modulation monitor or FM modulation monitor. You do not want to know the price of the analyzer and coms monitor. But to appease the curiosity, both combined hits the price tag of over 12 grand. And they were new when I bought them.
I am currently considering purchasing another LPB TX 2-20 and coupler from a camping park near Yellowstone that retired it and replaced with a newer Radio Systems unit. That will be used to expand the outer range to the south east so I can get coverage between Casper and Glennrock. A lot of scattered rual residential area there.
Will I add to the audio chain? I doubt it. At least in the way of spending dollars I wont. If something is handed to me sure why not. Right now I am quite satisfied with the audio chain, its sound quality is superb for the stations.
There is nothing wrong with putting the money in front first. I do not mean to or intended to make anyone feel like I was throwing them to the fire pit for doing that. I just find it odd to invest in the sound system first before spending the money on the vehicle that gets that sound trucking down the airwaves road.
RFB
March 12, 2011 at 1:16 pm #21240RichPowers
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Total posts : 45366I just find it odd to invest in the sound system first before spending the money on the vehicle that gets that sound trucking down the airwaves road.
Again, I do see where you’re coming from, and comprehend your point, however, it’s really a matter of perspective when you consider it.. the sound system/processing actually is also a major part of the vehicle that gets the signal out, particularly when it comes to Part 15 AM broadcasting..
When it comes to range, – is it not of major importance to modulate the signal to it’s highest capability in order to ensure that the signal penetration can achieve it’s maximum potential?
And isn’t the only way to accomplish that by incorporating an array of gear which is designed to achieve that?
Without it signal penetration suffers, and in-turn the usable range decreases. And the ultimate goal is the signal being received in the desired area.Sure, the xmtr and antenna system is the vehicle, but the petrol, transmission, wheels and tires are the processing equipment.
Or perhaps the other way around.. the transmitter is the transmission, and the processing equipment is the engine.. whatever, the point is that both are required, or you ain’t going anywhere.
You can work on an old car in the back yard till you get the engine running and tuned to perfection, but it’s not going to go down the road or even leave the property until the rest of the vehicle is road worthy.
The initial steps always refer to the final outcome. Why should it be considered so odd if you cater to one part of it before the other? It all goes together to form a single result in the end.
Just my view from a non-technical angle.
March 12, 2011 at 1:39 pm #21241RFBurns
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Total posts : 45366Sure with AM having peak modulation means peak amplitude of the carrier, in turn maximizing the signal thrown out the antenna. That can be accomplished by one single unit in the audio chain as far as processing, such as an Inovonics 222. Properly adjusted, you would not need anything else in front of it other than your program sources. Over processing is just that…over processing and actually tends to cause one piece of gear to fight another as the audio makes its way to the TX.
Walk into a commercial station and ask to look at their audio chain rack. I doubt you are going to find more than 1 or 2 pieces of processing in the chain…if more than 1 at all. Then there may be one more unit out at the transmitter site to process the incoming STL audio a bit further. Other than that…you are not going to find 30 band eq’s or audio exciters or dynamics processing. In a recording studio or production studio…yes..but in an on air broadcast studio….very very unlikely.
But go for it. As you said and I agree….its personal preferences. I see nothing actually wrong with it for others desires to put that much in front of the TX. For me…I find it pointless to have the audio bouncing back and forth with one processor processing a previous processor in turn processing a new output so it is again processed by another and yet again before that audio is so manipulated prior to hitting the TX.
There is really only one reason why commercial stations set their Optimod’s to produce loudness…that is to be competitive with their competitors. Loud is not always necessary. Loudness does not mean better content. You can have clean audio quality and good content, and you can have excessively loud junk content..but loud nonetheless. Which one would bring in the audience…the loudness or the quality of the program content?
If you could examine the audio on an audio spectrum analyzer before and after all that processing..you will see exactly what I mean about chopping off fidelity in exchange for loudness. Then there is the limitation of receivers ability in regards to bandwidth…especially on AM and the narrow NRSC curve. The only reason why that is in place..is to compensate for the manufacturers of radio receivers refusal to make AM radios with more than 5khz of audio bandwidth. So with that in mind….no matter how much punch or push or shove you put in there, in the end its all capped off and chopped up by the limited receiver’s mere 5khz narrow window. This is of course only applicable to radios with no bandwidth choice of narrow and wide like that found in C-QUAM equipped radios. But the majority out there….5khz…7 at most.
RFB
March 12, 2011 at 1:47 pm #21243RichPowers
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Total posts : 45366That can be accomplished by one single unit in the audio chain as far as processing, such as an Inovonics 222. Properly adjusted, you would not need anything else in front of it other than your program sources.
Yes, to me that’s always been the golden grail for Part15am, and I would have bought that one that sold for under $400 about a month ago had I not already exhausted my funds on the equipment I did buy.
Maybe it would have been better to wait till a 222 deal showed it’s head.. but those case seem to be far and few between..
But one day I will get a Inovonics 222.the audio bouncing back and forth with one processor processing a previous processor in turn processing a new output so it is again processed by another and yet again before that audio is so manipulated prior to hitting the TX
I can’t help but wonder on that statement.. The 222 is a all-in-one processor, so naturally I assume that inside that single box it must consist of several individual processing components working together to produce it’s final achievement.
I mean in reality it’s not just one piece of gear.. it’s just all in one box.
Or rather, that’s the way I perceive it to be.
No?March 12, 2011 at 2:17 pm #21244Carl Blare
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Total posts : 45366Creed
I believe in signal processing. In this discussion we have mainly been thinking about getting the tiny RF signal to sound as manly as possible. But even if we were talking full power radio there are reasons for tailoring the audio, and not simply to be louder than the other stations.
The world is noisy. All the noise people have around them is competing with your sound. Therefore you want soft passages to be boosted up to where they can be heard above the surrounding world noise. But you do not want to blast your audio so tightly to 100% modulation that you cause listener fatigue.
Listener fatigue occurs when a person begins to hear your sound as annoying rather than pleasant. To avoid this, some dynamic range between loud and less loud needs to be preserved.
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