Managing delay induced by outboard effects

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Phyl

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I tried the search engine on this topic but obviously wasn't using the right search words since I found zero threads.

Suppose you've recorded some tracks using whatever - SONAR in my case - and have decided you want to add an effect to a single track, let's say reverb. You have also decided you want to use an external hardware unit to add the reverb which involves sending the signal out of the computer, incurring delays in the hardware device, and bringing it back in.

What can you do (in anything) about those delays? I understand that when using a software plug-in the delay is managed by the computer, it somehow knows how to re-syncronize the tracks after a processing delay has been induced. When using a hardware solution do you...

a) ignore the delay and assume it's inconsequential.
b) add delay to the non-processed tracks.
c) do nothing because the tracking software handles it.
d) insert your solution here.

Thanks for your help!
 
if plug-ins are processed, then there is no delay because the processing is not performed in real time.

if you print your reverb track in analog and you see a slip, slide it back. since you use sonar, it's easy to SLIDE the wave.
 
Cross, thanks for the reply.

I'm imagining a scenario where I send an analog track out to a reverb unit (lexicon, tc electronics, etc) and then bring it back in. If it's possible to slide the audio track backwards, I guess I'm all set.

How do you know how much to slide it?
 
I use my lexicons outboard in sonar and with verbs and delays I have not noticed any reason to re-align effects or their printed tracks. What the hell, half the time a "30ms" delay in a pcm-80 is no where near 30 ms anyway! Sorry- off topic. :o
If you were mixing and returning something like a compressor it might matter, in which case you would try to look for a spike and zoom in on it and slide one. Might want to record a spike to make it easier as even drum hits look pretty smooooth at full zoom.
Byby:)
 
The idea that, when using internal plug-ins, all tracks are automatically time- aligned is in most cases a misconception.
However, again in most cases, the latency (time delay) this introduces is very small.
To counteract this, you can time stamp the original and allign the processed version to the original time stamp.

Please note that if you introduce a reverb you are talking about a kind of delay anyway, therefore, again in most cases, worrying about latency is rather futile.
 
I have no experience with routing to outboard effects and latency but does it matter what soundcard you use?
 
The only time latency like that is a big issue is when you need to combine the original sound with the processed (latent) sound and you can end up with phase problems. This might happen if you were combining a heavily compressed sound with the original sound.

But if the processed sound is 100% wet or it completely replaces the original sound than the latency isn't an issue unless you can notice the delay. In that case you just need to move up the original track or delay all other tracks by the appropriate amount.

FYI- Anytime a track goes through a DAC there will be some amount of latency added. It's really only noticeable to me on fast percussion parts.
 
Thanks guys!

One last question. Would using an external unit with SPDIF in/outs decrease the latency significantly?
 
I haven't tested it so...blat! i'm guessing. it would be shorter w/o having to do the extra ad-da, da dee da, yhea?


hmm..am I having toomuch fun lately?
oops.
By by:)
 
if you use an SPDIF or AES linked I/O you obviously stay in the digital domain, avoid one D/A and an A/D conversion. Therefore your latency would be reduced as compared to using analogue outboard gear.

Some DAW software allows you to time-stamp the original, some does not.
If it does not, and you need to export an audio file for processing, make sure you notate an accurate position of the original and check the new file against this position when you import the processed file.

(and they say digital saves time ???????)
 
Pro Tools has lists of the amounts of delay that each plug-in would add to a track. Some of the mastering plug-ins can add significant delays, but since they are usually added equally to both sides of the whole stereo mix, it doesn't really matter.

In general, on stereo tracks you would definitely want to install plugins equally on both sides so that you don't introduce noticeable phasing.

But on individual mono tracks within a mix, there are some people who add up all the delays and then shift everything around so that they all still line up perfectly. Personally I'm way too lazy, but there are those who swear it is worth the effort because it makes a significant improvement in the sound, detail and imaging of the mix.
 
Correct me if I'm wrong here, but even with a S/PDIF'd outboard loop, the audio still has to make a trip across the PCI buss to get to the soundcard and back, so there is some latency. On the way out, it's equal to the latency of the monitor out, so it effectively equals 0, but then as you record it back it becomes outbound latency, plus inbound latency, and will usually be noticable.
Most reverb algies have a certain amount of pre-delay, which helps to keep the dry sound clear before it gets washed by the verb. If it's a long pre-delay, then adding the latency delay to it can go overboard. Shortening the pre-delay by the amount of latency will bring it back to where you want it.
Another approach, one that works regardless of the processing involved, is to create a stereo sub buss with a track delay equal to the outboard effects loop latency. Then take all your tracks and send them to this compensation sub buss, which is then sent to the main stereo buss. The aux buss for the outboard loop gets returned directly to the main stereo buss. Now everything reaches the main stereo buss at the same time!
Regards, RD
 
Robert D said:

Most reverb algies have a certain amount of pre-delay, which helps to keep the dry sound clear before it gets washed by the verb. If it's a long pre-delay, then adding the latency delay to it can go overboard. Shortening the pre-delay by the amount of latency will bring it back to where you want it.
Another approach, one that works regardless of the processing involved, is to create a stereo sub buss with a track delay equal to the outboard effects loop latency. Then take all your tracks and send them to this compensation sub buss, which is then sent to the main stereo buss. The aux buss for the outboard loop gets returned directly to the main stereo buss. Now everything reaches the main stereo buss at the same time!
Regards, RD
Click to expand...

Gees, Robert. And this is easier? :D
Even with a/d-d/a it's just a few ms isn't it? I admit I have not mearsured my round-trip delay. What if it's two different effects?
Mostly we turn the verb and delay knobs till they sound right, and print tha danged thing.
I can barely keep up with all the routing going on as is.
Wayne:)
 
when i use to use outboard effects, i would patch them to the fx channel, and use them 100% wet.

are you doing this? wherein you record the effected track (let's say reverb since that's what you mentioned) and then set its volume to taste in reference to the original vocal?

that way you don't have to worry so much about the time shift because the time shift should be way less than your pre-delay setting. even if it is significant latency, you can play around with the effected track without ruining the position of the original.

of course this doubles your track count, but gives you alot of flexibility because you can increase/decrease the volume of the effected track, and slide it around to increase/decrease the pre-delay.
 
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