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Hi, I am currently evaluating the Broadcast processor and I am very impressed so far, I would however like to suggest a couple of simple extra features which would make this more suitable to my needs.
Firstly, I would like to be able to bypass the audio processing section altogether and feed stereo audio straight into the stereo encoder/mpx clippers and I would like to be able to select the input device for this as with all others, i.e an analog soundcard input OR a digital "virtual" input, such as a breakaway pipeline.
Secondly, I would like to be able to set an optional variable delay from the audio processing section into the encoder/clipper section.
The reason for this is that I would like to use breakaway at my main transmitter site, straight to the TX but I would then like to send the processed audio (from the L/R out) via IP to another site. This part I can see is possible and I have tested this succesfully but when it arrives at the other end, I would then like to be able to feed this straight into the encoder/clipper section of another instance of breakaway running at the remote site. My only other option would be to purchase a seperate hardware encoder and composite processor for this site which would be very expensive and would not give me good parity of processing between the sites.
Furthermore, I would like to apply a delay into the encoder at the main site to synchronise (as closely as possible) the audio from both sites to compensate for the IP link delay.Do you think that either of these features could be included into a future version?
The delay feature would not be very important but the first option would be very important to me.
Kind Regards,
Warren.
Hi Warren!
Breakaway Broadcast does not contain an MPX clipper. It does all its work in the L/R domain only, before stereo encoding is done. In this particular aspect, the layout of the processing is similar to an Optimod 8200, except that BBP’s stereo encoder is Digital while the 8200 had an Analog stereo encoder (after Digital Processing).
If the processed audio you’re feeding is not pre-emphasized, you could use the Protection Clip preset which already exists in BBP — I believe it will do exactly what you want.
If you are planning to feed pre-processed, pre-clipped audio from another processor, please don’t — I guarantee you that BBP’s clipper will do an audibly and measurably better job than anything currently out there. 🙂
If I (for example) had an 8200 in the studio, and wanted to run BBP as a clipper at the transmitter site, here’s how I’d set it up:
I would set the 8200 to 50us regardless of what country I was in, and I would turn Final Clip Drive all the way down, and I would also turn HF protection limiting down as far as I could (but I don’t remember off hand how flexible the 8200 is in allowing adjustment of these settings). Basically, I’d want the 8200 to do agc and compression but not clipping or HF limiting. Then, I’d use the Protection Clip preset in BBP, and adjust the Final Drive slider in BBP for the appropriate amount of clipping. That way, the final result will sound like an 8200, except it’ll magically be missing most of the distortion. 🙂
Delay and second input — it may possibly happen at some point. I’ve wished for it myself a couple of times actually. No promises though — the gotcha is that I’m trying to keep the BBP layout as simple as possible, being an entry-level FM processor. If I can figure out a sensible way to do it, I’ll consider it.
///Leif
Hi leif,
Thanks for your reply…
So tell me if i’m right here, if I stream the L/R out from the main BBP box, it should be "encoder ready" at the other end. Would this be suitable for any coder or would it still need to go thru another BBP (in bypass mode)?
I also gather from other threads that this audio will not be encoder ready if I use an encoder such as AAC+ or MP3pro as these employ spectral replication and as such will not properly re-create the tightness in the HF frequencies? If I use MP3 or WMA though, should this still arrive intact?BTW… Not planning to use any pre-processing, I want to let BBP do all the hard work for me. I was just wanting to use one BBP to do all the work at one site, then pass the processed audio to a second site with all the hard work done and put it thru BBP the other end but just the encoder part. From what you have said tho, I assume this effect can be gained by using bypass mode, thus the audio coming in, will not be touched by BBP again, just encoded and passed out to the transmitter, or if what I think you’re saying is right, it could go into any coder.
Oh, one other thing, I like to be able to control the AGC and multiband ride speeds seperately, is this possible in BBP as the speed control seems to affect both. Maybe I’m wrong here?
Many thanks,
Warren.
Hi Warren!
BBP’s L/R output audio is encoder ready. No further processing, clipping or filtering is necessary (or desirable).
However, the only lossy codec I know of that passes peak-controlled audio acceptably is MP2 (NOT MP3), and then only at very high bitrates (320 or 384).
MP3, WMA and all the others create way too much overshoot. You’d need a clipper at the other end. If you need to use one of those codecs, you should run BBP at the other end of the codec instead, at the transmitter site.
The speed control in BBP indeed affects AGC and Multiband together. There’s no way to separate them — my only suggestion is to choose the preset that is closest to where you want to me.
Best,
///LeifHi,
I’m nearly there I think… correct me if i’m wrong…
What i’m trying to achieve is to use ONE BBP at the main TX site to process the audio and for the audio from the L/R to be streamed to another site (this would be captured digitally and streamed out from the same box). The audio from the second site should sound (as close as possible), identical to the main site with perceivably the same level and also be within spec (no overshoots).
Main site takes care of itself.
Second site receives incoming processed audio (de-emphasised as this will also most likely be used as source for webstream). I wont be able to use High BR MP2 so let’s assume i’m using AAC+ 80Kbps with SR and all it’s inherent audio errors and overshoots.
I would NOT bypass the BBP running at the second site, I would select the "Protection Clip 6db" preset (which if I understand correctly does not add any processing to the audio but just passes it to the final clippers which will re-adjust for any overshoots added by the streaming process) and then adjust the final drive to get similar looking display on the output clippers as the main site (I will be able to monitor the main site from the second site). This audio would then just pass thru the BBP encoder in the normal way (RDS injected as usual) and to the second TX.
Is this what you would describe as the optimal way to achieve my goal?
In essence, this corrects for errors in the audio (overshoots etc) from the stream, gives me near-identical sounding audio and gives back the peak control lost over the stream.
Hopefully I’ve got this nailed now..
Many Thanks,
Warren.
Hi Warren!
What you’re describing is ALMOST optimal. 🙂 It would work, and it would be great.
However, if you have two BBPs anyway, it might actually be slightly better to feed them both unprocessed audio.
The advantages you gain then is:
1. No peak control is ever lost, so no peaks ever have to be reclipped. Less distortion.
2. Clipping before running through a codec adds complexity to the signal. In the case of BBP, it’s not much, but it’s bound to steal at least a couple of bits. Running the audio through the codec unprocessed should sound better.
(Then again, I could be wrong here. Maybe running the processed audio through the codec sounds cleaner, since it’s closer to what the listener will actually hear, and enables the codec to do a better job.)Using Protection Clip to compensate for the overshoots would definitely work too, though, and it would probably be plenty good enough.
Best,
///LeifHi Leif,
When will you make a stereo enhancer like spartacus ?
Spartacus doesn’t seems to work perfectly…
Someone said that spartacus works like Orban 222A but I don’t think because spartacus is very dependant of the input level… Maybe am I stupid and can’t make it work… humm 🙂 …PS : Here is an example of a full wide Stereo stream that I really love !
http://213.251.163.123:8050/
This stream sounds very good for me and I wonder if BBP car sound like this ? what kind of settings to use ? for the preset and the stereo closed to this ?Thanks leif, This will help me very much although there will be a lot of experimenting to do in the meantime but now I will also use MPXtool to help with my measurements and I’ll really be able to see how much deviation i’m pushing and if there are any overshoots.
Just need to find a tuner with MPX output…I can’t help thinking this will not be easy.Warren.
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