Cross firming subs.
jthunderbass
Posts: 60
This weekend I am doing sound for a show and the stage is an L shape. The way that PAs have always been set up in this room is with the speakers cross firing. Basically it's set up so that the sound from each side of the stage meets in the middle and so obviously there is some kind of cancelation going on.
The speakers have never been facing the same direction in that room.
Pa is, Presons SL 24.4.2 Driverack 260 QSC amps, and JBL (yuck) speakers. On the up side the tops are those 212 SRX 3 way speakers, downside is JBL subs.
Is there a way to use this setup and maybe reverse the phase of one side of the stage or take it out of phase, or delay it in order to avoid the cancelation as much as possible? Maybe even run one side at a lower volume?
It will probably be a stereo setup and not using aux fed subs.
I love aux fed subs.
Would it be better to just stack the PA on one side so that all the speakers fire the same direction?
The speakers have never been facing the same direction in that room.
Pa is, Presons SL 24.4.2 Driverack 260 QSC amps, and JBL (yuck) speakers. On the up side the tops are those 212 SRX 3 way speakers, downside is JBL subs.
Is there a way to use this setup and maybe reverse the phase of one side of the stage or take it out of phase, or delay it in order to avoid the cancelation as much as possible? Maybe even run one side at a lower volume?
It will probably be a stereo setup and not using aux fed subs.
I love aux fed subs.
Would it be better to just stack the PA on one side so that all the speakers fire the same direction?
0
Comments
Subs are pretty much omnidirectional so it matters little what direction they are aimed and if there is distance between two subs, you will get the typical power alley with cancellations on either side of it. switching one sub out of polarity will make a real mess.
Of course, you can do this with DSP but it's best to do the development work in a program to get good starting points...
It's just gonna be 2 subs and 2 tops.
I do love using SMMART with the Presonus! It is truly amassing the improvement.
I have been experimenting with it, and I'm finding that if you EQ using the mixer, it sounds ok, but if you use the Driveracl, whichever model you have, it sounds so much cleaner.
I eqed using SMAART and the EQ on the Presonus and it was ok, but when I transferred the EQ curve to the Driverack it was amassing the difference.
Thinking it through, it really does make sense that the Driverack EQ sounds better, how many years has DBX been making eps? A lot longer then Presonus.
One thing I am wondering though is... I watched a video on using SMAART to EQ, and all they did was use the parametric EQ, not the graphic. Is it better to EQ using only the parametric EQ or the 31 band? I've been using the parametric and finding it to sound so much better then the graphic.
On your initial baseline tuning of a system, you would use individual output PEQ's and tune low, mid, and high separately and use delay to time align. all of this would be done with the measurement mic fairly close to the speakers. This setting would be saved as a starting point and each venue would require a little touch up which could be done with input PEQ or GEQ...your choice