claessonedwards.com

Hey Leif,
It's been awhile since my last period of monitoring the forum. I just recently logged back in and lo 'n behold it's Christmas in October! Breakaway FM... how cool is that
Of course I downloaded the trial version right away. At first sample it sounds pretty nice, but it's going to take a some extensive listening to tweak all the settings in to my sonic tastes. I'm not big on heavily processed audio but spectrally balanced, with some tasteful "sweetening" from multiband compression can make the FM medium sound great.
However I have a few questions.

1. The CPU demands have certainly increased (understandably) and have shown that my poor computer is pushed pretty hard to keep the audio stream glitch free. Any HD access in combination with OtsAV Pro causes noticeable dropouts, albeit small. So perhaps it's time to upgrade the o'l music 'puter to something a bit more suited to the task. Would BAFM take advantage of a dual core system?

2. I'm sending the processed audio to an Inovonics David II stereo gen with internal wideband AGC, 75uS pre-emphasis, 15kHz LPF, and peak limiting. Is it preferred to use 75uS pre-emphasis selection to shape the audio processing correctly in BAFM (compressors, limiters, overshoot control) and then enable the de-emphasized selection for the output to the David II?

3. Ok I'm ready to fork over the cash because I can't stand the trial commercials. Perhaps as a service to licensed users of the standard BA you can input your license info to silence the trial commercials but retain the popup's and still limit the FM trial to 30 days.

4. Curious to know... what are the compressor frequency bands you use for the Plutonium preset (if you care to share this info)?

Nice job once again... at this rate Bob Orban or Frank Foti might be asking you for a job soon

Cheers

Joe D

Hi Joe!

Glad you could stop by, call me santa any day .

1) Yes they have. The reason for this is the extremely advanced clipper back-end in Breakaway FM.
On the FM medium, we have pre-emphasis to deal with -- audio must be broadcast with a very sharp treble boost (subsequently EQ'ed out inside every tuner), and all this treble causes peaks. These peaks would cause overmodulation and would mean we'd have to turn down the volume by at least 10dB, leading to a very quiet and/or dull sounding station. So, BaFM does not hold back -- it does the best darn job possible, but it does need some CPU. Not that much by todays standards though -- it runs fine even on the cheapest dual core cpu (Celeron E1200, $49) and uses only 10% on the cheapest core 2 quad (Q6600, $189).

BaFM absolutely takes advantage of dual core systems.

2) The cleaner the chain is after BaFM, the better. You'll get the very best sound from completely removing the David II from the chain and using BaFM's MPX output directly into your exciter (with a 192k sound card). You'll need to use an oscilloscope to adjust TILT and MPX PEQ to compensate for your sound card, but once you've done that, you will probably have the cleanest and loudest station in town (at the same time).

If you must use the David II stereo gen, turn off its processing as much as possible. Any crossovers, filters, clippers or compressors must be completely disabled, as they will cause overshoots for no gain. BaFM's output signal is already STRICTLY low pass filtered to 16 KHz, leaving 3 kHz of pilot protection. The David II would have to run as a straight stereo-gen with no other processing at all.

3) Got paypal? . It's not officially for sale yet but I can sell you a copy now, and you will of course be able to use your license key with the full version when released.

4) The crossover cutoff points for the 6-band presets are: 36, 49-145, 171-507, 599-1775, 2097-6212, 8235. Note that the first one is low-pass, the last one is high-pass, and the remaining ones are band-pass.

I've already worked for Bob a long time ago, before Octiv got started (1999) -- not happening again, but there's always Frank .

///Leif

Awesome... this is good to know!


My sound card is not capable of generating the composite signal (Echo Mia) so I need to stick with the David II. Plus I'm running SCA subcarriers and need the David II to add these into the composite.


This I will play with. My initial tests with minimal David II processing seemed ok and no overshoots were obvious on the mod-monitor. More experimenting is needed to find the right combo.


I do. What is the user name to send xmas cash?


I was referring they come work for you because your going to put them out of biz...
... Or perhaps they'll offer you a big bag "o" cash for your company and IP.

BTW I updated my normal BA to the latest version and my license key does not work. The data entry box has a new field "company" for which my license key has no information for. All I've got is name and key number. Leaving this field blank causes BA to reject my key. How to fix?

thx.

Alright. As long as you can disable filtering and crossovers as much as possible, it might be okay. Make sure, though! Look at the MPX output of the David II with an oscilloscope, and use the 60hz Square Wave and Quick Sweep tones from inside Breakaway FM. Make sure they're both flat -- not tilting / tapered. All it takes is a little bit of tilt and you've lost a full dB of loudness (and thus signal to noise ratio) for nothing. Peak control is *extremely* critical on FM, as you know .

Hey, depending on the frequency of those SCA's, you MIGHT be able to pass them through Breakaway FM.

The RDS input is low-passed at 80 KHz. Thus, a 92 KHz SCA will not pass, but a 67 KHz will, and so will RDS / RDBS signals (57 KHz). If you used this, you'd also see them on the BaFM oscilloscope, when set to composite. 192 KHz capable cards are not expensive today, so it may be worthwhile.

If you feed Pilot to the RDS input as well, BaFM will lock onto it for its own stereo generator. Thus, if you feed phase-locked Pilot + RDS, it will stay phase locked through the whole chain.


You may also be interested in another project of mine -- MpxTool.

http://mpxtool.com

It's a modulation monitor + oscilloscope + spectrum analyzer + stereo encoder/decoder + RF spectrum analyzer + mpx recorder/player + a/b comparison tool, all in a single piece of software!


I'll PM you the paypal account. Trying to avoid spambots .
You probably know the price from hearing that commercial one too many times.


The new version of BAP does need a new license key -- we're completely changing the authorization system, getting rid of the Hardware IDs. Email support - Keith will give you a new key.

Best,
///Leif

I can directly disable the "processing" portion of the David II, however the LP filter and overshoot correction are still active. BUT... by setting BAFM to 14kHz the measurable overshoots on the monitor are drastically reduced with no noticeable loss in "brightness".
I must say the difference in sonic clarity going from the David II's processing to BAFM is nothing short of amazing. And this was using BAP as the "front end" processor first. I had BAP set up such that the David II AGC and limiters were barely functioning. Eliminating the David II's processing and switching to BAFM made the vocal presence really stand out. I may not be the loudest sounding signal on the dial (don't want to be), but it's sure the cleanest. Comparing it to a local station whom I know is using the 8400 Orban box, their audio signature is very "stuffy" and flat... evidence of excessive limiting. It's hard listening to that signal even for a short period. A 100kW FM audio trash compactor. bleh...

I'll try sweeping and scoping the airchain output to see if there is any tilt. I'll let you know what I find should any others have an interest.


Might be an interesting experiment. I would be interested to see how spectrally clean the whole composite signal is when doing this test. SCA's have a nasty habit of mixing with the pilot generating "birdies" if there are any non-linearities present within the signal path.


You are one busy guy...
... one very neat product too

Do you ever get time to enjoy Thailand much, or are you perpetually glued in front of your work stations?

As a hint be sure to use part of my payment for BAFM and get yourself a few of those famous Thai massages... you certainly have earned it.


Thanks will do.

Cheers