analogue latancy

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i've been hearing what sounds like phase discrepancies or latancey when i route my aux channel fx return back into the desk - does this make sense, I can't think of anyway around it, all jacks are ts. seems to happen with all digital fx units - no sir, i don't like it!

[Kris]

"seems to happen with all digital fx units ".....

then you're not experiencing analogue latency.

Just out of curiosity, if it's effects you're routing back in how are you actually able to tell? And if it's on reverb, delay etc....is it really a problem?

[Linear]

i've been hearing what sounds like phase discrepancies or latancey when i route my aux channel fx return back into the desk - does this make sense, I can't think of anyway around it, all jacks are ts. seems to happen with all digital fx units - no sir, i don't like it!

I would check the phase of your input/output cables. Maybe even bypass the FX box, and mix the original signal with the send/return signal. It could be that something, somewhere along the line is inverting signal. When you add the effect, unless it is 100% wet, you'd be getting some kind of phase issue.

Maybe also try setting your effect to be 100% dry, and blend it with the original program. If it sounds funny, then you have an inverting problem.

Cheers

Chris

[Jeremy H]

I've had the same issue. I figured it was the latency of the digital fx - processing time.

You may wish to try this.

Record a 1k 0vu test tone to two tracks. Say 1&2. Play the tracks back through the board.- send one pre fader through the digital fx (find an effect where you dont actually change anything - like digital compression with a 1 to 1 ratio - but keep all your levels the same in and out - but don't switch to "bypass") - and back to another board input. Say channel 3

Playback the tracks with track 1 fader at unity, - bring up the fader on channel 3. The effect return. If the outboard signal has been inverted somewhere - the two signals should nearly cancel. If they partially or slightly cancel - it's latency. Don't rule out that it could be both!

Now - if you have the test tone recorded to two tracks and your recorder - assuming it's digital - has a "slip track" function, like the Alesis HD 24 - you can slip track two backwards in 10ths of 1 millisecond increments. (Or you could cut and paste it back a little in relation to track 1 - if you don't have a slip track function. But remember one digital "frame" is over three milliseconds - so we're talking sub frames here!)

Now it's trial and error in regard to time aligning the two test tone tracks. When you get it right the two signals at the desk, with both faders(1&3) at unity, will add to each other . By 6db I think in theory.-But they will not cancel each other because they are back in phase.

I measured the latency this way with my alesis, M3500 board and outboard digital fx. I found going through a digital processor - introduced between point two and point three of one millisecond latency. If I introduce another AD converter to use the digital IO of the outboard fx and then DA convert again to get back to the desk - I measure around point eight of a millisecond latency.

Like you, because of the phasing issue I can't live with it. And I can't figure out what the pros do either - because digital effects in an aux. send set up will always have some phasing issue, because all digital effects have some processing latency. So to me, a digita effect on an aux. send is worse than useless. And even if you use them as an insert effect on one or two tracks in a mix - well I now reckon I can hear point three of a millisecond spoiling the vibe!

I also sent a recorded tone track from the alesis, through the desk and back to the alesis. A track "bounce" not a track "copy". I couldn't measure any latency. So i assume the Alesis is internally "synced" to allow for it's own AD DA conversion time when doing overdubs etc.

So you could keep all your outboard gear analogue (and I

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thanks, will try those suggestions and let you know. kris, i called it "analogue" because the signal path is tape > mackie 8 buss trk "1" > aux send to fx > return to mackie trk "2". soloing out the fx return it sounds fine, channels mixed 1 & 2 i get the phasey sound - it sounds cheap and wrong.

[Linear]

thanks, will try those suggestions and let you know. kris, i called it "analogue" because the signal path is tape > mackie 8 buss trk "1" > aux send to fx > return to mackie trk "2". soloing out the fx return it sounds fine, channels mixed 1 & 2 i get the phasey sound - it sounds cheap and wrong.

I've heard that sound before.

re-check your cabling, that is the problem here. also see what the box expects, it's not always pin2 hot. i've had this exact problem with a BSS compressor, it's a bit weirdass.

Chris