Use LR Output as HiPass + 1 Mix out for Sub

Qu Qu General Discussions
1

First post here. I have just bought a QU-24, but have not yet taken delivery (next Monday - Yay). I currently use a Mackie CFX20 MkII + 2 outboard racks driving a QSC QSub and 2 x JBL powered speakers as main FOH. I use a Behringer CX3410 as an active crossover to keep the high energy bass frequencies away from my JBLs. I prefer this to using the Sub Out on the mixer since this does not remove the bass freqs from the LR Mains.

My question as a total newbie (I have studied the manual and viewed the YouTube vids) is can I set up the LR Mani outs to have little or no bass via the EQ. I would guess, yes here? I also want try and use one analog out to drive my sub. I don;t care if this is L+R full spectrum since the sub a). won’t respond to upper frequencies and b). there is not much relative energy there anyway.

The alternative would be to keep the CX3410 and use is as I do today but, I really don’t want to do that.

Thanks for helping me out. I am sure to be back.

2

You probably want to read these threads first:
use equaliser to put low pass filter in place
Feeding subs via Mix 5-6 using LPF, as a substitute crossover
The first thread also contains some frequency plots showing the difference between a faked (using EQ) and real crossover.
If you just want to protect your tops, this may work. If you bought a Qu in order to make great sound, stay with or maybe upgrade your crossover.

3

Thank you Andreas for pointing me in the right direction.

Frankly I was never happy with using EQs for crossovers and your posts and graphics really reinforced what I already knew. It is not the right way to do the job. One of my goal in buying a QU-24 was to reduce the amount of outboards, cables and interconnects.

For now I will keep the CX3410 because it works fine and has done for a few years. Yeah, I know, its Behringer. Later I may just buy some QSC tops which have internal crossovers designed to work together with the QSC sub.

It would be nice if future software releases for the QU could incorporate algorithms for at least Butterworth and Linkwitz-Riley crossover filters with various octave slopes and frequencies. Maybe I will stick this request in the features section once I have learned enough to ask questions.

Thank you again.

4

Feature request already active: Lo cut & Hi cut on Master & Matrix out :wink:
Personally I’d always prefer using an external crossover within the amp rack, not burning a mix on the Qu for such.

5

Thanks again. I need to learn this forum. I shall spend some time just browsing and searching.

I agree that an external dedicated crossover is a better solution if you have the space and the time. No question about it in my mind. My current goal is quite simply to reduce the amount of gear I have to carry to a gig. I am no longer 25 years old. Less gear means I have fewer interconnects, fewer cables and that means a faster setup and I also need less space. Heck If I use my Android tablet I could even go and sit at a table with my wife at some gigs.

6

Pop the crossover in with the amp rack…

7

All the speakers are powered. The only “rack” on stage will be/should be the AB168 dSnake box. Nice idea though.

8

Best solution would be if a Matrix out could be switched into some X-Over mode along with a Mix or LR sum. Someone could add that idea to the above referred feature request.

9

I agree. I reread the manual and realized that this is probably the best starting point. I shall now have to wait until Monday evening when I bring the QU-24 home. Then the fun will start. My last digital mixer was in about 2005 and nwas a Soundcraft 328. A much earlier generation.

Thanks for all your help. I am sure that I shall need more.

10

I got my new QU-24 home last night. Wow, what a great mixer. I am loving it. I shall now spend the next couple of weeks learning it before I take it its first gig next month. Then the fun starts.