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Hi All,
I’m currently using Breakaway Live and wondering what kind of benefits there are for using the High Pass Filter…and what setting would be best…I know the default is 30Hz…I think.
Thanks for your time!
FrankHi Frank!
The benefit is that it filters out thumps, rumble and other sounds that are too low frequency to hear. Very few sound systems play 30hz, and very little music has (intentional) frequency content below 40hz.
To put it simply, the more you can filter out while keeping the audio sounding the same, the cleaner your output audio will be, since anything inaudible is wasting headroom.
Best,
///LeifThanks Leif!
Makes total sense!!
Thanks for a great product…been waiting for a processor like this for a long time!
Frank
[quote author=”Leif”]The benefit is that it filters out thumps, rumble and other sounds that are too low frequency to hear.[/quote]
I would only comment that some of those sub-audible sounds may not be recognized by most ears but decent speakers will still vibrate at those lower frequencies, increasing the impact of some of that low bass. The "invisible bass" that you feel!
Indeed. Broadcasters tend to focus on the things that are audible (as anything else means less loudness), but this is why the high pass filter is defeatable.
Best,
///Leif[quote author=”Leif”]Indeed. Broadcasters tend to focus on the things that are audible (as anything else means less loudness), but this is why the high pass filter is defeatable.
Best,
///Leif[/quote]
Filtering the lower band give benefits also in the AFC loop in the Pll Exciter, giving more stable stero image and reduced channel occupation when observed with a spetrum analizer in "max Hold" , but Why not lower the High-pass to 20 Hz ? , i have measured lots of fm exciter , and they don’t show frquency drift until you don’t go lower to 10 Hz.. so 20 Hz can be a good compromise??Adriano.
Phase linear high pass filters cause LOTS of delay. A 30hz brick-wall high pass filter such as in BBP uses 16384 taps (!!). This means a delay of 16384 samples. (Yes, theoretically only half, but you have to buffer at both the input and output.)
A 20hz brick-wall high pass would probably need to step up the number of taps.. That is, 32768 samples, or a full 743 milliseconds (yes that’s seven hundred and forty-three), JUST for the filter. It doesn’t seem worth it.
If I made the filter non-phase-linear, it wouldn’t add any delay at all (at midrange frequencies), but then we’d lose phase linearity — not an option for me. However, you can always add your own filter as an effect plug-in!
Best,
///Leif30Hz is also the lower technical limit as it applies to most, if not all, government licensing standards ratified for FM broadcasting.
Not to mention that most FM stations on a system that can accurately play back 20hz… is not very fun to listen to (compared to CDs, mp3s, etc).
I wonder if some people realize how dang LOW 30 Hz is ??
An open Low B string on a 5-string bass… is 32.7 Hz. And that is REALLY low as far as most music goes. Not to mention even there, any producer with half a brain knows that you really have to enhance the crap out of the harmonics if you have a prayer of making it halfway audible on most people’s playback systems.
I don’t believe most do, Jesse.
In fact, if I ran an FM station, and cared at all about loudness and cleanliness, I’d use the 45 Hz high pass filter.
As an example, the Bose Wave Radio impresses a lot of people (myself included) by how low the bass goes. Then, I ran a sweep. It stops around 65 Hz.
///Leif
quote :…the Bose Wave Radio impresses a lot of people (myself included) by how low the bass goes. Then, I ran a sweep. It stops around 65 Hz.Interesting. Is this 65Hz cutoff based on speaker cone physical displacement, or does it include enclosure resonance?
Probably a combination of both (the box is limited in size, even though it’s a folded horn internally, and the drivers are just 3 inches, if that.) Probably has an electronic crossover too, to save power.
My point is, though, that 30hz is indeed much lower than people think. Music *very rarely* goes below 40.
///Leif
[quote author=”Leif”]In fact, if I ran an FM station, and cared at all about loudness and cleanliness, I’d use the 45 Hz high pass filter.///Leif[/quote]
Leif, is this valid for Web Streaming, also?Bye. 🙂
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