look ahead?!?!

sandrob · Post by **sandrob** » Fri Nov 09, 2001 6:43 am

i can't understand how works "look ahead" function on pulsars realtime compressors?!
how compressor can "know what will come" if is attack time (for example) shorter than LA time?!!?
i understand LA function for native efects in wavelab, but in realtime recording?! pulsar-compressor use some telephaty maybe

sandro

<font size=-1>[ This Message was edited by: sandrob on 2001-11-09 07:17 ]</font>

sinix · Post by **sinix** » Fri Nov 09, 2001 6:56 am

The sound is probably pre-buffered before processing as to give the processor enough time to analyze data.

I guess it's more or less the same way a hardware brick-wall limiter with "look ahead" works.

I'd think this is how it works, but I'm just taking an guess.

- sinix

Funktastico · Post by **Funktastico** » Fri Nov 09, 2001 2:34 pm

Yes, when you set the look-ahead to let's say 1ms, the compressor delays the signal by 1ms, buffers it, and compresses it - it doesn't look into the future.

Toni L.
http://www.mp3.com/NativeAlien

sandrob · Post by **sandrob** » Sat Nov 10, 2001 12:57 am

yes. thanks, now i see. when i set la to higher value i hear delay in headphones.
that's mean that recording in cubase late for la time!
can anyone teach me which is compromise. which la time set for recording, how much is enough for buffering - specialy for vocal recording, because my compressor is sometimes suprissed with unexpected signal?!
thanks!

sandro

p.s. few days ago i sale my tl-audio compressor and now i feel little sceptic about pulsars comps.

:

Funktastico · Post by **Funktastico** » Mon Nov 12, 2001 12:10 am

Depends on what you want to use the compressor on.

If you use it on the entire mix then the delay doesn't matter, so it can be high if you need fast attack. If you use it one one channel only, 1-3ms shouldn't be very audible.

Sometimes it's good to use a higher attack time if you want some track to better stand out of the mix.

Experiment.

Toni L.
http://www.mp3.com/NativeAlien

Post by **garyb** » Mon Nov 12, 2001 9:37 pm

you've described a situation that hardware comps handle better,overloading.often the a/d converter is already clipped before the signal reaches the pulsar compressor.the hardware device being analog clips gradually and might still sound ok. it's better to mic properly and use good mic technique, than to depend on the limiter to handle anything more than smoothing minor peaks,but for hardcore limiting of live(not virtual) signals, an analog device is mandatory as anything even slightly over maximum in digital completely overdrives the entire signal.once recorded, digital's low noise floor negates it's input limitations.(analog can still give an acceptable reproduction even when overdriven beyond it's dynamic range,digital cannot)

Funktastico · Post by **Funktastico** » Thu Nov 15, 2001 6:25 am

Actually I find it pretty hard to clip Pulsar's A/D convertors in normal use. Even if the meters in Pulsar mixer are going way past clipping, it doesn't sound like that. They seem to have almost analog-like headroom.. anyone notice this too or am I imagining?

Toni L.
http://www.mp3.com/NativeAlien