Gain Structure/Stock compression question

[Neil Sherman]

Hi guys,

Hopefully a noob question that can be fixed with a quick noob solution, but i'm stuck.

I'm new to Pro Tools, a bit green but not a complete novice.

I've recorded a bunch of kids singing. They were quite loud, and I recorded parts quite hot, but not clipping. Adding pro tools stock compressor, set to brickwall limiter, seems to be adding a load of distortion on the loud passages.

Removing the compressor plugin, it doesn't sound distorted. I can't see anything in the red on either the clip, the channel strip or the plugin. I'm wondering if there's some trait of pro tools gain structure that I can't see. I don't know why i'm hearing distortion. Any ideas?

Many thanks,

Neil

[Barry Johns]

There's a few different ways to accomplish what you're trying to do. First thing though, if you have clipping in the original track without any plug-ins, you simply need to re-record the track.

Clip Gain is your best option. If you're not familiar with clip game, just do a search on that.

You can also place a plugin before the compressor to trim the gain down before it hits the compressor.

An eq1 is fine for this.

In the digital world, you simply do not need to drive signal like you do in the analog world. Try to keep all of your incoming levels, no more than hitting the first or second yellow LED on the meter for each track.

You want to allow yourself as much headroom for the whole process ias possible.

[Neil Sherman]

I'd been doing all that. Is it possible that there is some kind of barely audible distortion from the recording that the compressor is making more audible?

I was hoping that someone would post something like. 'What are your meter settings? it's still possible for there to be distortion in the chain between x and y that isn't displayed anywhere'

I know I must sound like I really haven't a clue. Im just really surprised to hear this when I used nice mics and nice pres. I think I know what i'm doing!

[joachim]

I find that setting the attack in the stock compressor to less than 1 ms, it surely will start to sound noticeably distorted, in general.
Maybe a genuine limiter like the Avid Pro Limiter will be more suitable.

[albee1952]

Do you have a master track in the session? If not, add one and watch it for clipping. A single(or handful) of hot tracks may be fine, but a bunch, all recorded hot, and all mixed at -0 or higher might be clipping the mix bus(showing a master track will expose this if its happening).

You might also try a 2-step approach by using 2 compressor plugins in a row. Almost all of my vocal tracks have BF76, followed by SMACK! but any 2 plugins could work(advantage of BF76 is you can adjust the output down below unity, which the stock compressor/limiter doesn't offer).

[waltz mastering]

Originally Posted by Neil Sherman

I've recorded a bunch of kids singing. They were quite loud, and I recorded parts quite hot, but not clipping. Adding pro tools stock compressor, set to brickwall limiter, seems to be adding a load of distortion on the loud passages.

You usually don't want to brickwall limit more than a couple/few dB on any bw limiter or the sound can go south quickly. As mentioned, it might be best to feather it in with a compressor or 2 before you hit the limiter. On the comps you could start with a medium attack and fast to med release with a 4:1 to 6:1 ratio. Adjust the threshold on the comps to maybe get a few dB of gain reduction on the loudest parts and keep an eye on your output going into the next input. gl

[Neil Sherman]

OK I figured it out.

When I played back the backing track for the kids to sing along to, it was at full level.

Although the mic channel's weren't clipping during recording, the overall mixer in my interface (Steinberg MR816) was touching the red as the backing track was too high. I didn't want to start messing with the levels mid recording, so I let it play out, then went back to check the bits I thought might have peaked.

I thought they sounded ok and not distorted, although the clipping mixer, seems to have added some very low level distortion, barely noticable without any plugins. The poorly set compressor plugin was exposing the distortion more. I changed it for a more sensible compressor. In the end there were only a couple of loud words I had to fix on one channel, and it all sounds clean now. I was just scrathing my head the other night trying to figure out how I was distorting the sound.

So lesson learned about my kit, and confidence restored that i'm not going to accidentally distort my mixes.

I won't make that mistake again. Thanks for the advice.

N