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Unofficial Mackie User Forums => DL1608/DL806/DL32R/ProDX Mixers => Topic started by: Robj on December 02, 2013, 07:36:01 PM

Title: Pre DSP
Post by: Robj on December 02, 2013, 07:36:01 PM
Sorry if this is a stupid question.  On the Dl1608, is there a way to have reverb or delay on a channel in an aux mix without having compression, but have compression on a channel in the main mix?  I know compression on a monitor feed for a vocalist can be detrimental.  But most vocalists I've worked with all want some sort of reverb or delay, even on their monitor mix.
Title: Re: Pre DSP
Post by: RoadRanger on December 02, 2013, 08:35:52 PM
Interesting point, you can have the "dry" voice pre-DSP in an aux but the reverb itself is generated from the post DSP voice. OTOH it's always been done this way AFAIK unless there is a separate monitor mixer - even on analog mixers. I wouldn't worry about it.
Title: Re: Pre DSP
Post by: WK154 on December 02, 2013, 11:06:31 PM
There seems to be some confusion on the use of channel eq's etc. I cannot see a value of two separate processes for an artists input unless you want to complicate your life. If the artist is happy with the single channel process and you can send that to the IEM or monitor for his/her feedback leave it be. I don't know of a successful artist that doesn't want to know what his customers (you know the ones that pay the tab) are hearing. The room acoustics are handled after the mix and compression and GEQ are available. Delay unfortunately is not available for speaker control.
Title: Re: Pre DSP
Post by: sam.spoons on December 02, 2013, 11:26:19 PM
As far as I can tell no, it's not possible as the DSP works as a block.

I would like the option to have channel eq, reverb and gate on the aux but no compression for example. The logical conclusion of this would be aux taps between each element of the DSP and the ability to choose the order of the DSP elements (i.e. eq first or last, compression before or after reverb or aux send etc). This should be possible entirely in software.
Title: Re: Pre DSP
Post by: WK154 on December 03, 2013, 12:07:57 AM
Then you would love the features of the Acapela16 or the IS16 (mix and match orders of effects). Subgroups etc..
Title: Re: Pre DSP
Post by: walterw on December 03, 2013, 05:33:29 AM
Sorry if this is a stupid question.  On the Dl1608, is there a way to have reverb or delay on a channel in an aux mix without having compression, but have compression on a channel in the main mix?
is this a trick question? set auxes "pre-DSP" as you should, then turn up the delay and/or reverb faders in each aux's mixer view as needed.

(i don't know why they call it pre-DSP; isn't the entire mixer "DSP"?  ???)
Title: Re: Pre DSP
Post by: Harpman on December 04, 2013, 04:50:14 PM
Sorry if this is a stupid question.  On the Dl1608, is there a way to have reverb or delay on a channel in an aux mix without having compression, but have compression on a channel in the main mix?  I know compression on a monitor feed for a vocalist can be detrimental.  But most vocalists I've worked with all want some sort of reverb or delay, even on their monitor mix.

I never run compression on vocals main mix or monitors.  You lose the dynamics of the vocalist when you compress.  I do compress instrumentation, buy very sparingly.  If you are using compression to avoid FB issues, then you issues lie elsewhere (EQ, etc).  I've actually experienced compression on vocals causing FB due to incorrect compensation of makeup gain.  I've attached a couple of images that hopefully have come across.

Sent from my iPad using Tapatalk HD
Title: Re: Pre DSP
Post by: Wynnd on December 04, 2013, 05:04:17 PM
I can't see how compression would help with feedback.  You raise the floor while limiting the ceiling.  That's an easy way to increase feedback or reduce GBF.  (Gain Before Feedback) I've wondered if using gates might help reduce feedback by shutting off mics that aren't being sung into at the time.  In my band, we have 7 vocal mics and 2 horn mics.  Generally most harmonies parts are about 3 voices.  That's shutting down about 5 mics most of the night while not preventing anyone from using their mics.  (Might reduce drum bleed thru too.)  Any thoughts about this? 
Title: Re: Pre DSP
Post by: Greg C. on December 04, 2013, 06:02:38 PM
I never run compression on vocals main mix or monitors.  You lose the dynamics of the vocalist when you compress.  I do compress instrumentation, buy very sparingly.

I can't imagine not using compression on vocals in the main mix, especially with a powerful PA system. Or even a weaker one for that matter. The human voice can be one of the most dynamic instruments you put through a PA. With a powerful system without compression, one moment a vocalist can be barely audible and then the next moment be blowing people out of the room. Compression helps with both situations. For weaker PA systems that might be lacking in headroom, compression can prevent the system from clipping but still maintain relative vocal "loudness" in the mix. When I'm using a full blown system with a lot of processing at my disposal, I use a combination of channel and bus compression. Channel compression is minimal, usually between 1.5:1 and 2:1 ratio with fast attack and release with the threshold set to kick in when things start getting to a "medium loud" level. Then the vocal bus compressor is set at ~6:1 with fast attack/release with the threshold set to kick in when vocals start to become a bit too loud. The 2 stage compression keeps things smooth since compression is minimal for relatively nominal vocal levels and only comes in hard when it needs to. The bus compression is also great for a lot of vocals simultaneously for harmonies and choruses where a lot of voices can get things really loud suddenly.

I make pretty liberal use of compression on instruments as well, but I'll leave that for another discussion.
Title: Re: Pre DSP
Post by: WK154 on December 04, 2013, 06:40:50 PM
I can't see how compression would help with feedback.  You raise the floor while limiting the ceiling.  That's an easy way to increase feedback or reduce GBF.  (Gain Before Feedback) I've wondered if using gates might help reduce feedback by shutting off mics that aren't being sung into at the time.  In my band, we have 7 vocal mics and 2 horn mics.  Generally most harmonies parts are about 3 voices.  That's shutting down about 5 mics most of the night while not preventing anyone from using their mics.  (Might reduce drum bleed thru too.)  Any thoughts about this?
One of the principal function of set it and forget it mixers such as the XAP800 and others is to reduce amplification by 3dB for each doubling of mic count. Accomplishing this without mixer automation is exhausting. Yes it allows for more gain before feedback and it works but setup is critical. DL gating isn't up to the job it needs more intelligence on the part of the mixer. Mute groups may help with this manual effort if four groups will cover your situation. Mic placement can sometimes get you much more than after the fact band aids. I would experiment with that first.
Title: Re: Pre DSP
Post by: Wynnd on December 04, 2013, 07:05:54 PM
If I weren't playing at the same time, it might be an answer.  On the other hand, if I had bandmates that truly understood that you can get a good mix without blowing the speakers up, we wouldn't be having this conversation.  I figure that the frustration I have with that band will chase me away.  I'd doubt that I'll be working with them come February.

Already setting up a low volume group with all the PA in the backline and no monitors.  I can walk in right front of the speakers with my headset mic on and have no feedback issues.  It's such a pleasure to hear everything.  I've never even bothered to set the anti-feedback with these guys.
Title: Re: Pre DSP
Post by: WK154 on December 04, 2013, 07:16:47 PM
I never run compression on vocals main mix or monitors.  You lose the dynamics of the vocalist when you compress.  I do compress instrumentation, buy very sparingly.

I can't imagine not using compression on vocals in the main mix, especially with a powerful PA system. Or even a weaker one for that matter. The human voice can be one of the most dynamic instruments you put through a PA. With a powerful system without compression, one moment a vocalist can be barely audible and then the next moment be blowing people out of the room. Compression helps with both situations. For weaker PA systems that might be lacking in headroom, compression can prevent the system from clipping but still maintain relative vocal "loudness" in the mix. When I'm using a full blown system with a lot of processing at my disposal, I use a combination of channel and bus compression. Channel compression is minimal, usually between 1.5:1 and 2:1 ratio with fast attack and release with the threshold set to kick in when things start getting to a "medium loud" level. Then the vocal bus compressor is set at ~6:1 with fast attack/release with the threshold set to kick in when vocals start to become a bit too loud. The 2 stage compression keeps things smooth since compression is minimal for relatively nominal vocal levels and only comes in hard when it needs to. The bus compression is also great for a lot of vocals simultaneously for harmonies and choruses where a lot of voices can get things really loud suddenly.

I make pretty liberal use of compression on instruments as well, but I'll leave that for another discussion.
I would have to agree and disagree with you on this. Try that on an opera trained artist and you'll have a noose waiting for you at the end of the gig and that's before the DIVA factor of how dare you change my artistic expression. On the other hand most rocker's are half deaf and wouldn't even notice. Cool man yeah! It's not a subject for a broad brush answer it depends on the artists. I just did that with the rocker comment. My bad.
Title: Re: Pre DSP
Post by: Wynnd on December 04, 2013, 09:04:34 PM
Didn't think that opera singers bothered with a PA.  (Really!)
Title: Re: Pre DSP
Post by: WK154 on December 04, 2013, 09:32:20 PM
Old school kicking and screaming new generation not so much. Times change and theater productions mostly insist on head mics.
Title: Re: Pre DSP
Post by: Greg C. on December 04, 2013, 09:35:24 PM
I would have to agree and disagree with you on this. Try that on an opera trained artist and you'll have a noose waiting for you at the end of the gig and that's before the DIVA factor of how dare you change my artistic expression. On the other hand most rocker's are half deaf and wouldn't even notice. Cool man yeah! It's not a subject for a broad brush answer it depends on the artists. I just did that with the rocker comment. My bad.

Occasionally I will run across a vocalist with impeccable mic technique that can work the mic like a self vocal compressor (watch Christina Aguilera live sometime). But they're rare. And I still like to to have at least the limiting comp inline just in case ;)
Title: Re: Pre DSP
Post by: Wynnd on December 04, 2013, 09:39:19 PM
Politicians and Preachers are the worst.  It's the rare politician who really knows how to use a mic without hiding his face.  It was Preachers who got me to even try compression with speeches.  I usually run about an 8:1 ratio with them. 
Title: Re: Pre DSP
Post by: walterw on December 05, 2013, 02:51:54 AM
yeah, the importance of compressing vocals out front was the impetus for one of the biggest fixes of the 2.0 upgrade! if you want a pro-sounding pop-rock mix you gotta compress the vox at least a little, so quiet singing doesn't disappear while loud singing blows up the room (or your speakers).

its probably the number one use if you only have a single channel of compression.

(4:1 with fast attack and release, set so normal singing gets you just a few dB of reduction, sounds natural to me while keeping the vox just on top of the mix where it belongs.)

the issue with feedback is from compressing monitors, which you don't wanna do.
Title: Re: Pre DSP
Post by: Wynnd on December 05, 2013, 03:22:43 AM
This assumes that your FOH isn't louder onstage than the monitors.  My bandmates have gone insane on volume.  I'm just waiting to blow the horn drivers again. 
Title: Re: Pre DSP
Post by: Fluddman on December 06, 2013, 10:18:41 PM
This assumes that your FOH isn't louder onstage than the monitors.  My bandmates have gone insane on volume.  I'm just waiting to blow the horn drivers again.

I feel for you Wyn. I am in a slightly similar situation but at least mine is improving slowly. Our noisiest band mate has started using in ears - that way he can have it as loud as he wants without ruining it for the rest of us. One problem is he really can't tell how loud he is relative to the rest of us and sometimes his stage levels are way to high - but at least now he is happy to turn the stage volume down and his in ears up.

I do play in another band which is focused on keeping the volume down and the sound balanced with vocals soaring over the top. It is bliss!

Cheers