# processing outputs **URL:** \ **Category:** SQ General Discussions\ **Created:** [8 June 2020 08:52 UTC](https://forums.allen-heath.com/t/processing-outputs/9831 "2020-06-08T08:52:13Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![danielr](https://avatars.discourse-cdn.com/v4/letter/d/f17d59/32.png) [@danielr](https://forums.allen-heath.com/u/danielr)\ **Post date:** [8 June 2020 08:52 UTC](https://forums.allen-heath.com/t/processing-outputs/9831/1 "2020-06-08T08:52:13Z")
The main goal for this is I want a “virtual crossover” to save some space taking rack gear places. I know that some people use aux fed subs, (eg assigning channels to Aux1, as well as main L/R outputs) then apply filters to Aux 1 to restrict the frequency. but this suffers from the issue that when you turn down (or up) the main mix, you need to adjust a separate fader for this sub control. By default the Main L and Main R are assigned to output 11/12, but they can be assigned to any/all outputs. The issue is that it appears to be the processing is on the channel, not the output. (so I want to assign Main L to out 1,2,3 and Main R to 4,5,6) then have different band-pass filters, time delays and output gain applied to each output, (not the Main LR.) But the only way I can see to accomplish this is to use a short XLR to loop L/R back into a pair of desk channels (not routed to LR!) and then feed these channels to auxs with appropriate filters/time delays etc. then assign the aux channels to outputs the drive amplifiers. Is there some other way that I haven’t thought of? - or do I need to just keep using an external crossover? ---
**Author:** ![markpaman](https://sea2.discourse-cdn.com/flex002/user_avatar/forums.allen-heath.com/markpaman/32/3163_2.png) [@markpaman](https://forums.allen-heath.com/u/markpaman)\ **Post date:** [8 June 2020 09:17 UTC](https://forums.allen-heath.com/t/processing-outputs/9831/2 "2020-06-08T09:17:45Z")
So, it looks as if you have a three way speaker system that you need a crossover for? The loopback you describe is going to introduce D/A & A/D delays, making time alignment difficult, if not impossible. It’s also going to eat up a lot of inputs & outputs. Look at feeding L&R to the 3 matrix outs (in stereo), and using the PEQ & delay they have to achieve a _sort of_ crossover. You can then patch these to 6 output sockets. It may work for what you need, thought I’d go for a proper crossover / speaker processor unit. ---
**Author:** ![mikec](https://avatars.discourse-cdn.com/v4/letter/m/977dab/32.png) [@mikec](https://forums.allen-heath.com/u/mikec)\ **Post date:** [8 June 2020 12:00 UTC](https://forums.allen-heath.com/t/processing-outputs/9831/3 "2020-06-08T12:00:57Z")
I am all for NOT having main system processing taking place with in a mixer…because - The system will only work with that mixer. - What if you need to do last minute mixer replacement. - Too easy to get into the settings and damage the system. - It uses a lot of the mixer’s outputs. There is a lot of good system DSP processors available today at all price points. You should carry a spare DSP in some form or another just in case. For what it’s worth I carry a spare DSP, spare power amp and a spare mixer that will let me get the show done if needed. ---
**Author:** ![steffenromeiss](https://sea2.discourse-cdn.com/flex002/user_avatar/forums.allen-heath.com/steffenromeiss/32/2684_2.png) [@steffenromeiss](https://forums.allen-heath.com/u/steffenromeiss)\ **Post date:** [8 June 2020 13:47 UTC](https://forums.allen-heath.com/t/processing-outputs/9831/4 "2020-06-08T13:47:03Z")
> but this suffers from the issue that when you turn down (or up) the main mix, you need to adjust a separate fader for this sub control. not if the mix is post fader > The issue is that it appears to be the processing is on the channel, not the output. that’s the way it works and that’s why it is a mixing desk not a PA processor there are very cheap processors available, some with very small footprint like MiniDSP, Xilica Solaro QR or WorkPro AoIP Line devices and there are more… ---
**Author:** ![mikec](https://avatars.discourse-cdn.com/v4/letter/m/977dab/32.png) [@mikec](https://forums.allen-heath.com/u/mikec)\ **Post date:** [8 June 2020 13:58 UTC](https://forums.allen-heath.com/t/processing-outputs/9831/5 "2020-06-08T13:58:16Z")
Choose a DSP that will take AES inputs to save a couple of conversion stages. I use DBX Venue360’s, they met the processing and price points needed for my systems and they will take AES inputs.