Topic: is this normal for the limiter? 722 waveform

[terrapinj]

mod460 >mk46/ck1x > 722 limiter engaged

the top of the wave form in the right channel seems to hold right around -6 but the bottom half peaks around -2.3, i have never had the limiter kick in of the 722 before, but i would expect the waveform to be more symetrical?

here is a 13MB / 3min FLAC file of the main section of the area where the limiter kicks in
http://www.sendspace.com/file/rpvvll

[BayTaynt3d]

What were you recording? Any brass in there? I'm not familiar with the 722 limiter, but does anyone know it's specs? This doesn't feel like a limiter thing to me, I'm not even sure the limiter was coming into play?

[terrapinj]

this was Skerik's Syncopated Taint Septet so there was a large horn/sax section.

the limiter is supposed to kick in right around -6 db which is where it appears to be kicking in on the upper half of the waveform. I know horns create odd waves but should the limiter still be engaging the lower half as well? The right channel still peaks around -2.5 which at that point the limiter should have been really kicking in.

i was running 1.74

[BayTaynt3d]

I know nothing about the 722/744, but don't limiter's typically have a higher threshold and a really large ratio? -6 seems a bit low for a limiter, sure that isn't the compressor? Like I said, you'd know more than me, but just asking... Also, was this going through the house PA or was it purely acoustic? Cause you could be picking up some crap from the PA too, I wouldn't rule that out either...

[kgreener]

i ran the limiter one time and ended up with waveforms exactly like this.  music was all distorted to hell and sounded like arse.  promised myself right then & there that i wouldn't run it again.  haven't had a problem since and i'm very pleased with the results without it.  YMMV

[it-goes-to-eleven]

The limiter has worked great when I've used it in the past. But I don't use it.

[terrapinj]

it came in through the house PA, i was bout 20' from stage or so. i couldn't set up a stand in the sweetspot so I just ran my actives in a hat, and engaged the limiter because I couldn't watch the levels very often, i cranked the gain way down after the 1st song. if you look in the left channel though it doesn't seem to have the issue and its below that 6db threshhold

[BayTaynt3d]

Manual states this: -4 thresh, 20:1 ratio, 5ms attack, 200ms release (should cap at -6)

Also, is the channels are "linked" then so is the limiter.

But, this doesn't explain your waveform, and now your results do look pretty weird. Except for very, very fast attack transients, you shouldn't ever see anything above -6. Weird. Is it possible the limiter was only engaged on chan 1? Is that even possible, that could explain it. The asymetical wave is from the horns, but only chan 1 was limited. Otherwise, that truely is weird?

[kgreener]

it came in through the house PA, i was bout 20' from stage or so. i couldn't set up a stand in the sweetspot so I just ran my actives in a hat, and engaged the limiter because I couldn't watch the levels very often, i cranked the gain way down after the 1st song. if you look in the left channel though it doesn't seem to have the issue and its below that 6db threshhold

Manual states this: -4 thresh, 20:1 ratio, 5ms attack, 200ms release (should cap at -6)

Also, is the channels are "linked" then so is the limiter.

But, this doesn't explain your waveform, and now your results do look pretty weird. Except for very, very fast attack transients, you shouldn't ever see anything above -6. Weird. Is it possible the limiter was only engaged on chan 1? Is that even possible, that could explain it. The asymetical wave is from the horns, but only chan 1 was limited. Otherwise, that truely is weird?

good points.  this happened to me too...i was recording 24-bit and had levels way down (~ -12) and still got distortion, mostly in one channel (linked gain)

[terrapinj]

i had the gain linked, but as you can see the left channel was much lower than the right (didn't fine tune the balance)

i'm gonna contact SD, just was curious if this was something normal

[CQBert]

When I ran the 722 the first few gigs I did with a the limiter and never had something that looked like that.  For the most part you could not tell that it was on, very smooth unless you were just banging +2 / +4 the whole time.

CQBert

[ghellquist]

What mics are you using? (Battery box or similar).

My guess is that it is the mics that are creating the problem, not the limiter.

Gunnar

[RebelRebel]

I regularly have waveforms resembling those on brass gigs. never mind the look, how does it SOUND?

[BayTaynt3d]

I regularly have waveforms resembling those on brass gigs. never mind the look, how does it SOUND?

We've already covered that Teddy. What's weird here given the limiter's specs, he should never go past 6. Don't you think his waveform is weird considering that? Especially with that attack, seems like nothing should slip by that far on either side of the polarity?

[it-goes-to-eleven]

I regularly have waveforms resembling those on brass gigs. never mind the look, how does it SOUND?

We've already covered that Teddy. What's weird here given the limiter's specs, he should never go past 6. Don't you think his waveform is weird considering that? Especially with that attack, seems like nothing should slip by that far on either side of the polarity?

As if Teddy doesn't know what horn waveforms look like!  You're wrong about the limiter.

The limiter STARTS at 6.  If you do any testing you'll see that you can still fully clip the 722 with the limiter.  And, of course, everyone should actually test the limiter before using it...

Now that we know horns are involved, I think the waves look pretty much as expected. At this point controlled testing is necessary.

[terrapinj]

The limiter STARTS at 6.  If you do any testing you'll see that you can still fully clip the 722 with the limiter.  And, of course, everyone should actually test the limiter before using it...

Now that we know horns are involved, I think the waves look pretty much as expected. At this point controlled testing is necessary.

to clarify there are horns in the band but there were none in this sample - drums/bass/organ - also, shouldn't the left channel look somewhat similar to the right if it was just the music creating the waveform?

good point about the limiter kicking in AT 6db not holding the music to 6db

[it-goes-to-eleven]

good point about the limiter kicking in AT 6db not holding the music to 6db

It isn't well documented in the manual.  I had a fair bit of discussion with Justin about it when I discovered the bass roll off clipping distortion problem.  Have you done any testing?

It would be cool to do a limiter vs. no limiter comp on a source that peaks below -6. Just to get an idea how much potential impact there is with the limiter enabled but not active. But I still wouldn't use it..

[terrapinj]

good point about the limiter kicking in AT 6db not holding the music to 6db

It isn't well documented in the manual.  I had a fair bit of discussion with Justin about it when I discovered the bass roll off clipping distortion problem.  Have you done any testing?

It would be cool to do a limiter vs. no limiter comp on a source that peaks below -6. Just to get an idea how much potential impact there is with the limiter enabled but not active. But I still wouldn't use it..

i didn't do any testing. i basically engaged the limiter for stealth situations in case i had my levels way too high to avoid clipping. i know there was nasty distortion with earlier versions of the firmware but that was supposed to be resolved now AFAIK. i have never had the limiter actually engage but this time i was apparently way too hot in the right channel.

im gonna try to do some more testing and see if i can replicate this

[BayTaynt3d]

Manual states this: -4 thresh, 20:1 ratio, 5ms attack, 200ms release (should cap at -6)

Also, is the channels are "linked" then so is the limiter.

But, this doesn't explain your waveform, and now your results do look pretty weird. Except for very, very fast attack transients, you shouldn't ever see anything above -6. Weird. Is it possible the limiter was only engaged on chan 1? Is that even possible, that could explain it. The asymetical wave is from the horns, but only chan 1 was limited. Otherwise, that truely is weird?

I wrote this earlier, but I think I got the 4 and 6 mixed up. But regardless, someone please tell me that with a -6 thresh and a 20:1 ratio with a 5 ms attack how anything gets much farther than -4? It'd have to be one hell of a loud and fast transient. So, for whoever said they still clipped with the limiter, I find that really surprising considering the specs of the limiter.

That said, now that I see I transposed the -4 and -6, that could potentially explain this. For the one channel nothing much makes it past -6, so not much limiting there. For the other channel, the one side of the polarity seems to be going past -6 but the other side isn't, which can be explained by horns, but he said there wasn't any horns in that clip. But regardless of that, it seems like there was an asymetrical waveform (could be coming out of the PA that way) that only got limited on the one side, because it was only that side that went beyond -6. And if you look at it, it seems like it got close to -4, but never beyond that. So that seems reasonable. It just looks a little weird because the other side of the polarity so perfectly holds its level that it looks like it was limited too -- but given the specs, it doesn't seem like it was in range to be limited yet.

[BayTaynt3d]

Also, is this thing limiting in the analog or digital realm? The R4 limits digitally, which seems pretty pointless to me, so I wonder about the 722?