I have set up a multiband compressor in a group track side chained to the vocal track with the idea to send instrument busses to it so that the frequencies that I have set in the dynamic compresser will be reduced in the instruments…thus making a bit of space for the vocal…
the problem I am encountering is that when I send an instrument buss to the dynamic compressor it’s raising the volume of the instrument slightly…
what am I doing wrong please?
cheers, Kevin 
Sounds like a damn complicated way to mix…
Sorry, flippant answer.
It’s an ingenious idea.
I’ve never tried it, am tempted to try.
Still thinking about this.
The multi band will only duck the frequencies you have set in it, as I understand it, not the actual frequency range of the vocal.
To be honest I can’t see a lot of point in this approach, but I’d be interested to hear if you get a result from it.
A compressor (not side chained) lowers the signal of the loudest sections making the overall signal have less volume and also sound less loud. After that happens there is usually a gain stage where you can boost the level of the overall signal. If you were to boost the signal back to the same volume it will sound louder than before. This is because those loudest sections have been boosted back to where they started while the previously softer sections have had their levels increased by the gain stage - so the overall signal now sounds louder.
Using side chaining to duck the signal you don’t want to increase increase the gain after the compression occurs. If that happens, even if only on a frequency range, it will sound louder. So make sure that isn’t happening. Some compressors have an auto “makeup” feature (actual names are all over the place) that you’d want off. Other compressors will always auto makeup the gain as part of their design & not give you a choice - don’t use those for this application. Some compressors also have an initial gain stage before the compression to raise the incoming signal which would also make it sound louder. This initial gain control is sometimes used to set the compression.
Try muting any signal into the side chain, which means no compression will occur. Then adjust the gain(s) in your compressor so the signal is the same when the compressor is bypassed or engaged. Now try setting your compression using the side chain.
You might find useful info here
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=audio%20ducking
Kevin, Try this too:
Sending the output of the group you want to attenuate to another group channel, (Second Group).
Second group: Phase invert the second group.
Second Group: Insert an eq and set a gentle high pass and low pass to pass the area you wish to attenuate. Like a telephone patch for instance.
Second group: Insert gate and engage side chain.
Vocal track: Activate a Send to Gate side chain.
Second group: Adjust gate attack and release to taste.
Ta DAH!!
That’s pretty cool. A very straightforward, clean approach. Thanks for pointing it out.
I have been using TrackSpacer a lot for about a year. It works great for the kick drum bass guitar issues. I haven’t tried it with vocals, but I don’t see why it wouldn’t work.
I also use Waves Vocal Rider with good results. I find that it gets me about 80% there. Once I have recorded automation with Vocal Rider I need to make minor adjustments throughout the whole track.
The difference between the two is TrackSpacer is dependent on frequencies while Vocal Rider is dependent on dB’s.
Ultimately I think a combination of the two would be optimum, but I haven’t had much time to do that.
Thanks for the replys…the vocal is the trigger track that hits the multiband compressor, I’m sending instrument group tracks to the multiband compressor via sends from said tracks, the multiband compressor is set to reduce frequencies in the mid range to make space for the vocal during singing,
this is instead of placing a multiband compressor on each instrument track sidechained to the vocal (trigger) track…
but cannot figure out why when I increase the send to the multiband compressor from an instrument track it increases the volume of the said instrument track.
this may have already been answered in one of the posts above but gotta get my head round what you guys are saying… 
I found the answers a little confusing so thought I’d re explain it in case I’d explained it wrong…
I’m easily comfused with routing so please forgive my backwardness on this subject…I apreciate your help guys…
Not trying to duck the frequency range of the vocal…using the vocal as a trigger to duck the frequency range of various instruments instead of having a multiband comp on every instrument track…
Got the quotes wrong in the above post…soz
so this will attenuate a frequency on an instrument track only when an input from a vocal track is present via sidechain??
I’m not sure I quite understand the question. If you are looking to duck the frequencies of the vocal track in the instrument tracks (thus making more room for the vocals) then yes.
Check out this review: https://youtu.be/fXDjtj6xC1Y
MBC works just fine for this, as someone said just make sure you have zero make up gain on your compressor. i normally use wide band comps to duck, quite often the steiny/yamaha 260 as it’s very fast and transparent, but i was mixing a track which was BVs heavy the other day where using the MBC to duck some conflicting frequencies in the BVs with the main vocal, i did eq them out first but it just killed them hence taking the approach i did in the end… worked brilliantly too!
yeah, thats what I’m trying to do, thanks…wil check out the vid…
yeah, thats what I’m trying to do, thanks…wil check out the vid…
ok, so it’s working just like a dynamic EQ… which is what I’m trying to do but I’m gettinga raise in volume when I send the instrument track to it…
S’pose the only problem with the spacemaker is I would have to put one on each track that needs ducking,
I was trying to send them all to one dynamic eq that was triggered by the vocal…so is this not poss then?
You keep talking about sending which I can’t tell is just you misdescribing what you’re doing or is the reason it’s not working!
If you want to reduce frequencies in the instruments you must route them to the group not send them…otherwise the original is untouched and whatever happens in your compressor can only add more to it rather than take anything out.
So route instruments to group, insert dynamics on group and sidechain from vocal.
Yep this is correct…
There’s a thousand ways to skin a cat!
Actually… kevin, it might be worth you just using the stock de esser to do this, just put it on the group/channel you wish to reduce frequencies in, identify which frequency range you wish to duck, activate the S/C button on it and then go to the channel you wish to use as your control channel and assign it to S/C the de esser from the sends panel from that channel… probably a little more straight forward for you.