How to Prevent Power Alleys From Ruining Your Low End

[@tolome7456]

This is some of the best quality content out there. Thank you man.

[@L0r1T0]

Such a great video for people like me, who have a small gig, most videos talk about big arrays with several subs, i had a lot of problems in my club because i placed my subs left and right and my audience asked for more volumen, but my neighbors were enjoying (not so much) the music. Brought me a lot of problems with the goverment.

[@MichaelCurtisAudio]

Glad the video was helpful for you!

[@iandwyer7050]

Really awesome explanation man. I’m still very new to audio and subwoofer deployments and made the mistake just last night of creating a huge power alley at a (luckily free) gig. Excited to apply these ideas to future configurations and see what happens!

[@MichaelCurtisAudio]

Give it a shot and let me know how it goes.

[@ambroselockerman1115]

Forgive me or point me to it, if you have already covered this, but in a venue where you are pretty much forced to do l/r sub arrays, do you have any idea how it would work to use two cardiod arrays, left 100-50hz and right 50-20hz and adjust the crossover accordingly? Would that sound too weird? Seems like it would have a better chance at more even coverage.

[@DjKarstenReisser]

Great usefull video, thanks! I really enjoy the good and visible explanation! I am a dj and mostly have gigs inside. So my subs happen to crossover at 100Hz. Is it correct to assume that, when I am in a small+long room, 7.53 feet from center woofer to center woofer is a good distance to position the subs? 🙃👍

[@Labaris]

Great video, very clear explanation, thanks! The thing I find the hardest in practical terms (for fixed installations in churches, specifically) is that sub arrays need to be placed right in the middle of the venue, between the stage and the first rows of the audience. That's probably of the second most important area in churches, at least on more traditional ones. So, the second-best options seems to fly the subs or just forget about them. Another one that theoretically works is to delay one of the subs in the LR layout, by the time it gets for the sound to travel from one sub to the other. That creates less pronounced SPL differences and, as long as the delay is not longer than about 30 ms, it shouldn't be noticable. What is your approach when you can't place the subs in the middle?

[@drummerdude4696]

Hello Michael. Thank you for sharing this information on using subs. I run mine in stereo and it seems to work well. But I'd like to get your thoughts on the pros and cons of using subs in stereo.

[@DJLEOdamadprofessor]

I’m just a DJ but I found this incredibly interesting and it’s opening so many questions I have about how I set things up and how much I’m missing in my sound

[@MichaelCurtisAudio]

Thanks a ton, man! Glad it was helpful to you. I've got another video that talks about Mains speaker placement as well: kzbin.info/www/bejne/hZbEfqeIq66sqa8

[@DJLEOdamadprofessor]

@@MichaelCurtisAudio just watched that video too great work thank you!

[@MichaelCurtisAudio]

@@DJLEOdamadprofessor You're very welcome!

[@MatbiangShadap]

Michael, will Mapp 3d Allow simulations for other speaker types like yamaha, nexo, etc.?

[@MichaelCurtisAudio]

Great question. MAPP 3D only has Meyer products. EASE Focus 3 by AFMG has .gll files from many different manufacturers. I have a tutorial on EASE Focus 3 here - kzbin.info/www/bejne/gpLCaKCkqph7qJI

[@SuAmigoElilegal]

Question here. I have my PA set. 2 12s subs and 2 loud 15inch power speakers. Now the subwoffer has a frequency selector on the back from 70-150 heartz. I'm guessing that is to cut off the frequency of the above 15 inch loud speakers. My question is what happends if I select the above 100 heartz frequency on the subwoffer. Do my loud speakers begin to loose their volume of sound 🤔

[@MichaelCurtisAudio]

That knob is selecting the crossover frequency in which your subs will start to hand off to your mains. You don't want too much overlap or you'll get a low end bump where you don't want, or you don't want a gap if you set the crossover too low. I'd check and see the recommended crossover from the manufacturer of your 15" mains speakers, then set your sub to hand off there. If you're unable to find that, 100Hz is a good place start, then work lower to 80Hz or so if that doesn't work. The best way to know is to put to do a test and verify with a measurement mic and software like SMAART/OSM.

[@huey8431]

Very interesting and informative! I’m trying to dial in two 18” subs for my home party. They’re one QSC active 18” and an SRX dual active 18”. My space is 18’ x 30’ . I’m trying to achieve chest hitting as well as deep bass for a party. What configuration would you recommend? I tried cornet loading the dual facing forward and back firing the single 18” along the center wall. Any suggestions is greatly appreciated!

[@MichaelCurtisAudio]

I'd go with an Occam's Razor approach here, keep it simple! 1. I'm not positive the QSC and JBL subs are phase compatible with each other. So, I'd choose one ore the other. If maximum SPL is your goal, go with the dual 18". 2. Put it against your center wall facing the wall. That will take advantage of the quarter space loading and the woofer close to the wall will eliminate any SBIR.

[@huey8431]

@@MichaelCurtisAudio thank you so much for the advice! I will try it ! I would not have thought of facing the speaker toward the wall to get chest thumping bass.

[@gabeangelomusic]

Love these videos! So recently I had a gig where the subs were already installed left and right of the stage. In that case is there anything that I could do to mitigate that effect?

[@MichaelCurtisAudio]

Thanks, Gabe! Unfortunately you're not able to apply any processing to mitigate the effects, but simply being aware that it's happening will help you make better decisions about handling your LF in the mix. Basically, always walk around a little bit and get a feel for multiple points in the room before shoving up your bass guitar +6dB ; )

[@gabeangelomusic]

@@MichaelCurtisAudio Makes sense thank you!!!

[@stevenbanquer8552]

Could we have the subs separated at a specific distance to have a good low end for the kick and then a ctr sub for just bass guitar to have our bass low end be more even and since the kick is pretty much mixed to exaggerate only it’s fundamental? Just a thought

[@MichaelCurtisAudio]

That'd be an interesting setup! The imaging might be weird, but give it a try.

[@canopygardensgreenhouse9907]

Great video, I knew speakers could cancel each other out when at an opposite polarity, never thought of the time of travel with the lower frequencies. If you don't mind, What would you recommend in a church stage setting where I have no choice, but to place the subs at the far left and right sides?

[@MichaelCurtisAudio]

For a church with a left/right sub setup? - pray : ) All jokes aside, there's not much you can "do" other than be aware of the problems it causes, then always take your low end mixing decisions with a grain of salt. Make sure and take a tablet with you and mix in the room, not just camp out in the booth.

[@canopygardensgreenhouse9907]

@@MichaelCurtisAudio 😆Thanks I'll pass it on. And Thank you for your quick reply. I'm in the process of watching all of you videos related to speaker placement. Now is my chance to get it right since it's still a construction project. if you don't mind one more, it's a vaulted ceiling I have room to hang speakers and it's looking like my best option, would you fly a sub in this situation? sorry if it's a bad question, going to watch your "they thought I was crazy video" next. Thank you!

[@MichaelCurtisAudio]

@@canopygardensgreenhouse9907 You got it! And yes, in most cases I recommend flying subs. And in vaulted ceilings I end up doing single center main speakers as well, then adding delays if necessary.

[@canopygardensgreenhouse9907]

@@MichaelCurtisAudio great! Thanks so much Michael.

[@canopygardensgreenhouse9907]

Micheal, would you be willing to do a little consulting for us? I would rather pay a professional than change my mind and rework and waste money. Thanks, Andrew

[@germanboza]

This video was extremely helpful and eye opening for me! Thanks a lot! I’ll keep watching all your videos, there’s a lot to learn from you. I have one question though, does all this hold true if this is inside a room with walls, floor and ceiling? I would expect the reflections to have some influence there.

[@MichaelCurtisAudio]

So glad the video was helpful to you! Yes, room and wall reflections definitely have an influence here. In short, it makes the deep valleys you see here less pronounced. It "fills in" some of the gaps in energy with some late reflections. The low end feels looser, but it's better than a 36dB discrepancy! I am more apt to push for a center sub setup when doing shows outside since I do not have the luxury of walls helping fill in the gaps.

[@germanboza]

Is there any simulation SW than can be used to predict how the subs would perform in a given room? Or can they only do open field?

[@MichaelCurtisAudio]

@@germanboza MAPP 3D can show you how reflections off walls incorporate into the prediction, but you would need the full version of EASE to calculate room modes, decay times, etc.

[@jthunderbass1]

Hmmm. So what if I do a spaced pair of subs in the middle of the stage, get a space to the correct wave length, and then a run one kick mic to one of them and the other kick mic to the other. One bass guitar channel to one sub and the other bass channel the other sub?

[@MichaelCurtisAudio]

Dave Rat uses this approach (sometimes). I'm not sure what you mean by "correct wave length", but yes, in theory this could all work to a certain extent. Two kick mics means that yes you'll have two representations of the same kick drum, but they'll still be correlated to some degree since it is indeed the same source. I would test how much actual decorrelation you would get between two different microphones. There will of course be timing differences do to the mics not being able to be in the exact same point in space, but if there's not much difference from a phase or magnitude perspective from the mic capsules and circuitry themselves, then it will be the same as having a mostly correlated duplicate offset in time by a millisecond. Same thing with the bass guitar. A DI line and an amp line will have much different phase and magnitude responses since the bass cab will have a ton of LF delay due to speaker design, so better chances there.

[@jthunderbass1]

@@MichaelCurtisAudio When mixing, I use the In-Phase plugin from Waves on 2 kick mics, or a Bass DI and bass amp. It is a time alignment tool that uses delay and all pass filters to align sources. I have considered using 2 of the same kick mic on kick drums instead of the normal 2 that I use.

[@MichaelCurtisAudio]

I haven’t used that one from Waves! I’ll give it a whirl next time I’m in a Soundgrid situation. Yea, most engineers underestimate the phase smearing a cab will do vs the DI for bass!

[@marcobarri1874]

Hi Michael, thanks for all of your videos! I may ask you one question: If you are running a simple setup like 4 subs and 2 tops in an open space, which placement would you suggest for subwoofers if you can't apply any delay? (i.e. you are running a PA without any processing). Thanks

[@MichaelCurtisAudio]

Hey, Marco! Glad you've enjoyed the videos. I'm assuming if you're in an open space it's a wide audience, so I would do a center "cube". Two subs right next each other in the center, then two more stacked directly on top. I talk about the array specifically in a section of this video: kzbin.info/www/bejne/h2XRqmpmaNpgodU

[@marcobarri1874]

@@MichaelCurtisAudio Thanks! That video was exactly what I was looking for, you got a new subscriber!

[@SimonSerbern]

Hey Michael Maybe i missed something, but rewinded a couple of times. Can you ellaborate on how you calculate the distance between the centered (put apart) subs :)? Loved your video! Will dive further in to your channel next :)

[@MichaelCurtisAudio]

Glad you enjoyed the video and thanks for the question. I've actually changed my stance on spacing subs a little bit since filming this video. I think I mention that you calculate a 2/3 wavelength at your crossover frequency to pull apart subs and narrow coverage. I would now advise to do no more than a 1/2 wavelength. As an example, if my crossover was 100Hz, its wavelength is 11.3ft. Divide that by two and that's 5.65ft.

[@SimonSerbern]

@@MichaelCurtisAudio gotcha! Thanks :)

[@singtall]

why the change of stance on this? measurements in the field?@@MichaelCurtisAudio

[@bkozyra31]

what happens if you put the endfire array built into a stage? will it still work?

[@MichaelCurtisAudio]

It will not, unfortunately. All cardioid sub arrays work best with no near boundaries or reflections.

[@akindipeoluwadamilare591]

Thank you so much for this

[@MichaelCurtisAudio]

You're welcome!

[@broadcastedtube]

Great Intel to avoid power alleys

[@MichaelCurtisAudio]

Thank you!