I had a left and right set up about 50 feet apart in the church. I use map to predict and saw all the cancellations and the flower petals. So we relocate them underneath the stage a half wave length apart My crossover frequency is 125 Hz I have two subs in the middle touching each other then I’ll spread the others to wavelength apart when I did the prediction again, it look like a gigantic pear. And the energy that the audience get now is amazing so I agree with all this that you’re trying to teach and I appreciate you thank you so much.😊
I've been using half the subs I used to use and getting the same or even more power thanks to these useful tips. Thanks for the great work and for the metric spreadsheet, very needed for my portuguese workflow. (feet here are only for wearing shoes :D)
This was so helpful, I am just setting up dual subs and ive realised that the cardioid option is the , one I should adopt , as I'm in a brewery and there is a row of tanks behind the stage area, I have built the subs inside two large rum barrels and was going to put them both on the same cradle after watching this they need to be on separate cradles to really increase my options, thank you for explaining things so clearly
There is literally nothing too nerdy or in the weeds for me. Please always elaborate! This has been an excellent intro to setting up smaller systems man!
Had a gig with the same subs I have now in the "traditional" LR setup and kept hearing/feeling the alleys/valleys and this video completely visualized what was happening. Going to be using a center cluster with them this next time around and I'm very much looking forward to my walk around, with and without people.
love the content. The spreadsheet shilling does get a little tiresome, but these videos are pure gold. I've probably learned more watching the videos you've made in the past week than I have about sound in months. I'm a 18 year old currently attending college while trying to get more into the event production game. Currently doing events with fraternities and the local area. I'm in charge of sound for our business, so learning more and more about the physics of sound and knowing more about speakers is super helpful.
Glad you're enjoying the videos! I'll have some more varied free resources coming soon. The spreadsheet is helpful to folks, but you're right that I mention it in a large percentage of my videos.
Great video. An additional option I use is to stack the two subs on the left side at our church where the drums and bass are located. Adds a bit of stage location to the sound in the room and when people think the the low end is too loud they can move to the right side 🙂 I happen to be using D & B Audiotechnik cardioid subs which greatly simplifies things greatly
@@MichaelCurtisAudio … so would I do this same center coupling with my two passive Yorkville LS1208 scoops because normally I would do the left & right set up with a qsc 15” on each one inside big ballrooms and it would sound pretty good to me I’ve never center coupled my big scoop’s before but I always couple my powered EV Etx’s and they always hit so much harder!
Thanks mate, a few videos ago (the one about column speakers one) I asked you which one would you prefer: one double driver sub or two single driver sub, as I was building a small PA. I followed you advise and ended up with two single driver subs. This video is gold for me, I will definitely experiment with the different configurations. Also thanks for the metric version of the spreadsheet!
Hi Michael, great video! Can you please consider doing one talking about portable column array speakers for portable dj's as well? Myself and many people I've seen online have doubts in relation to many aspects: they advertise a very good horizontal range like 120º, they almost always pack a small sub like 10, 12 inch (do those pump out enough spl?) and some systems like the maui 28 have built in processors for cardiod setups (would that help dj's), would they be good in a outside scenario. But also they advertise that they can be combined in pairs, so what distance from one another should they be? can we use a different sub with them? Hope you find the time!
Great video, thanks! Probably, aligning the rear sub more precisely in the inverted gradient array would yield to better results. Also, lowering its level a little bit might help
@@MichaelCurtisAudio thanks. I'm currently working on a design for a church where the subs can't be in front of the stage, so I'm considering putting them under it and use a cardioid array in conjunction with bass absorption and detailed dimension of this cavity they would be in. It's a hard one
@@Labaris Cardioid arrays unfortunately fall apart when under a stage. There's too many reflections for the careful conditions of cancellation to occur : /.
@@MichaelCurtisAudio I figured that was probably the case, that's why I was thinking about designing finely-tuned bass absorbers inside the cavity (the space under the stage). But really, it doesn't seem to be a good idea actually. Thank you for your insights!
i have 2 12s in my volvo station wagon. with the back seats down its like a tiny empty room. the bass was best with them both next to each other in the back left corner, instead of one in each corner. only a two foot movement made a big difference.
I enjoyed this video, however, 1. I Wish you would have briefly shown the different frequencies with the last setup. 2. Whenever I've attempted to explain these concepts to any Mobile DJ or sound engineer at that level, I've received nothing but ridicule, ego, and insults on my intellect, and "it doesn't matter."
Hi Michael, I tried different inverted gradient stack configs in Ease Focus 3 and they all seemed to disagree with your delay calculations: They all ended up looking like a super cardiod pattern (in your video 16:43 as well there was a little blob projecting backwards). To mathematically investigate the issue I plotted the sinwewaves radiating from the subs in a math software. My result is that we have two options, a) to go for max summation in the front, or b) to go for max cancelation in tha back. a) is achieved by calculating the delay as described in your video (adding the horizontal driver displacement as a delay the bottom sub) b) is achieved by subtracting the horizontal driver's displacement from the half-cycle of the crossover frequency. In case of 100 Hz that would be 5ms minus the driver displacement in ms). Mathematically we can solve this set of equations for a and b to be true, so we have both max summaton in the front and max cancelation in the back. For this to work, both the horizontal driver displacement and the delay added to the bottom inverted sub have to be equivalent to a quater cycle (of the crossover frequency). For 100Hz that is 2.5ms (or about 86cm) displacement and delay. Thanks for your video!
So glad i just found you and subscribed, i've been running audio for many years but just with a simple point source system and some home made sub cabinets with a dbx driverack and passive amps (ALL CROWN MACRO K2 and XTI, but i have never really learned the intricate math behind why some shows work and some suck. i dunno if i can do much with just a basic driverack or learn more on how to position my stuff.
You can do plenty with the just the driverack! That unit is more gear towards aligning and tuning crossovers within a single enclosure, not necessarily a full rig, but it can work for that minus any serious output delay times.
Thank your for your amazing explanations !!! I have a little question : is it possible to used 2* 15" Sub combined with 1 or 2* 18" Sub ?? I would love a video explaining the advantages and disadvantages =)
I've been doing end fire cardioid almost always if I have two subs available... it gives even sound across audience and cleans up the stage and has very low setup and processing requirements. To do something more fancy one'd need thee or more subs and more processing :) I hate spaced pair subs that are very common...
Michael. So, as a low end sound guy, could you show what these positions would look like if I had 2 of the QSC cardioid subs… what do the power alleys etc look like if each sub is a self contained cardioid sub? I’ve always seen the dual 12” cardioid sub set L/R with the poles screwed into the sub and the top perched up there… it seems that this use might keep bass off the stage, but create the same alleys for the audience. So good for noise control on stage, but similar issues as single subs spaced L/R for the audience…is this correct. THANK YOU for this content, very educational!
Hey Michael, I think you were speaking to this at the end of the video referencing a 7th setup. But when you delay and flip polarity on the rear speaker in the cardioid setup, doesn't that mean your kick signal will be out of phase? Sure the peaks and troughs will line up, but you'll have a delay between transients on your rear and front sub. Isn't that a concern? or is it less of a concern than not getting the broadband rear cancellation as you mentioned when comparing to delaying the front sub with no polarity flip. Thanks for all your content! Super helpful.
so I have 2 Qsc k12.2 tops and 2 Qsc KS212C subs and i always place them left and right of my dj set up (1 top & 1 bottom) so is it better to put both of my tops on my left & right and both subs facing forward together/side by side in front of me?
For now I'm focusing on live setups, but a lot of these principles still transfer. I'd check out Jesco Lohan at Acoustics Insider for small room acoustics and speaker setups.
One thing I've done in the past where L/R subs are inevitable is place them so that the main nulls are in the aisles. Still not ideal but better than nothing
What is the best space to a hard wall for a 2 Subwoofer Cardiod - inverted gradient stack? If they are both away from the wall, the best space is as close as possible. But How is the best space, if one is facing to the wall?
Do you have any similar tutorials showing these graphs in a smaller indoor venue with wall/ceiling reflections being accounted for? Are the sound peaks/valleys in a left/right sub config really all that noticeable? For the vast majority of venues we play, it’s the most practical physical setup. Will a cardioid setup against a wall on one side sound all that much better?
the thing I wonder the most about sub setups is how much max spl for most of audience is lost for each setup compared to just putting the 2 together to get that full 6db increase because a lot of times I need to get The most max spl out of my RCF Dual 18”’s because I don’t have enough
Why you don’t consider an ‘end fire’ setup in a situation like that? That’s by far the best config in terms of efficiency, phase response and alignment in the front while allows you to have some rejection in the rear.
End fire is definitely a great option to have in the toolbag. I actually deployed an endfire array just yesterday. The reason why I didn't include it here is that I rarely have the real estate necessary to do ground stacked end-fire arrays, so have to default to more compact solutions like gradient stack. Gradient configurations also have a more stable coverage pattern over frequency when compared to end fire.
Half wavelength crossover center with JBL SRX828SP (dual 18). Assuming an 80hz crossover, lets call a half wavelength 7ft... where physically would I be measuring from on dual 18s, the center of the box? The boxes are 47.5" wide, so if placing 2 subs center-stage with 7-foot spacing from their centers, that would mean roughly 3-foot gaps between the left and right sub stacks is the max before the pattern starts to break apart, with an 80hz crossover. Am I on? Biggest thing I get hung up on with these spacing talks, is there's never mention on where to place the tape measure, especially with wide dual-18" subs.
Next time you should mirror your little webcam bubble so that you're facing the graph on the screen, the way it is now when you're looking at your monitor screen it makes it look like you're looking off to the side of the screen
If the stage isn't too wide I'd say it's just fine. If you have a wide stage the low end can feel "lopsided" from an imaging standpoint. I'd test it out - try a LR vs a side stack and see which of the tradeoffs you would rather live with.
Hey Michael great video! One question though, at 13:54 you talk about delaying the rear speaker. My brain says delay the front speaker so the sound waves travel together. Could you explain this! Cheers from the UK!
Really helpful video, has given me pleanty of ideas for next gig. Just a quick question if I’m trying to utilise a inline gradient cardioid setup. How do I add delay to one of the subs. I’m pretty new to this so might seem like an obvious question 😂. But I’m using 2x Mackie 18s subs and 2 x thump 15a loudspeakers. Would it involve adding delay through a mixer ???
You would need some sort of DSP to do that. You could use the internal prossesing power of an digital mixing console (if that's what you're using) or an external DSP/Speaker management system (like the Behringer Ultradrive or a DBX DriveRack). If you habe any further questions, don't hesitate to ask, I or the rest of the comunity will try our best to answer... I hope this helps :)
If working with rear ported bass reflex, how would you calculate using an inline gradient or a stacked gradient deployment? Generally, how would rear ported subs react as a whole in any configuration?
Michael @15:15 you said it was 2.17ft multiply by .88 gives you 1.909ms of delay but then your spreadheet you showed 2.17ms of delay...uh ? am i missing something ?
Hi Michael! So...if the subs are placed up to one half the wavelength of the crossover point (I'm using 80 Hz), you're still able to avoid power alleys and valleys? I'm I getting that correct?
Hey Michael, thanks as always! For the halfwave spaced setup: When you say "up to" the crossover frequency, do you mean by distance or frequency? For example, if my crossover is 80hz, is my spaced limit 7ft? Or can i space them more @ 11ft to boost 50hz?
If I set my subs center either side by side or stacked and the stage is tall (about 5’) and has a brick wall holding up the stage, how does the hard surface behind the subs affect the sound?
Thanks, Evan! I'd say it would probably be the center side-by-side setup. With just two subs having them as closely coupled as possible gets the maximum possible SPL out of the rig. It also gives the widest coverage pattern, which is often needed in outdoor setups. If the stage doesn't have a hard front and the subs I have are efficient (not needing to drive them hard to get the desired SPL), then I'll do an inline gradient seutp.
Impressive! Question: if you only have 2 sub in a home theater 20’x30x20 (WLH) what would be the response if you put the subs diagonally? That is front right, back left.
just put 10 boxes 1000W subs per front center, front left, front right, left side, right side, back center, back left and back right. in short, all around. then🤘
Cardioid Subs Explained For Normal Audio People - ruclips.net/video/EgHK1s7SzIE/видео.html Cardioid Sub Workshop | Inline Gradient - ruclips.net/video/e90v1NVT7bQ/видео.html
OK thanks, I'll take the time to watch that with thought. I guess I have had few misconceptions; firstly I thought that back-facing a sub reverses the phase, but it's not dipole speaker... Then I thought delay+distance are mandated by summation frequency wanted, but actually delay compensates the distance. I guess that distance is mandated by summation frequency then?
I'm not able to center cluster my two QSC KS118's (cardioid) because I have a video DJ booth. Is it OK if I put them on one side? My entire setup is no wider than 12 feet. Also, is it OK to cover the subs with a cloth covering to help conceal them?
You are amazing I really appreciate all that you put out there. I'm trying to set up a inverted gradient stack. If your soundboard/subs don't have a built in delay, what kind of hardware would you use if software isn't an option?
Let's say there is no stage and the band is playing on a concrete pad. Is it still best to do a center sub array if they don't mind seeing a sub or two in the center or is LR the best way to go to avoid looking awkward?
I'm a bit of a dinosaur and have not mixed sound since the Mackie analog boards were popular. Our pastor found out I used to do this and asked if I could help figure out how to add more bottom end to their system. They have a JBL powered subwoofer, i believe its the PRX series either a 15 or 18. The sound booth is situated on the side of the auditorium which I know is far from optimal and the sub sits next to it. After watching your video my question is can one sub work ? I now know we need to move it to the front center but I don"t know if we can rig this to the ceiling. Our only other option would be on the stage center but from what I'm understanding this is not good? The room is not huge and its wider than it is long.
If you're not able to put it center, put it in front of your stage off to one side. Like you said, optimal would be to fly it center. Even better would be to fly two of them in the center and space them 5ft apart of so so you can narrow the coverage.
i recently did an outdoor show. Audience area is size of a football field. I have two dual 18. I put them together touching. had a terrible valley. it was like you turned them off. it was narrow. i started to move them apart and kept checking it. the valley just got wider and wider. it was just dead. we usually do the left right sitch, and have that valley, but not as bad as with them pushed together. my setup did not match these diagrams at all. PS I was right in front of a concrete stage. what gives?
It sounds like to me one of your subs had a polarity inversion somewhere in the chain. They were "fighting" eachother when they were close together because you essentially had a copy of the sound wave coming from the same point in space, but inverted, therefore the sound from your subs was in a silent stalemate.
I was thinking that. They were purchased used. Who knows if some knuckle head "fixed"them at some point in time and reversed the wires. I know this because i had another set and that was an issue. Ill check all my wiring. Doing the same place this weekend again. Thanks for the reply. I really enjoy your videos. I run passive gear. So i don't have fancy built in polarity switches. Lol i guess the polarity built in to x32 would work. When measuring side to side placement...where do you measure from? Ctr to ctr? Outer edge? Where do you get the 5.6 feet? Can you build a dual 18 with a third facing rear?
Could you do an analysis over what the coverage be if subwoofers were up against a brick wall? Also, what would the response be if the subs were about 15 or 20 feet out in front of a brick wall?
Great questions, John. You can think of any hard reflective surface like a brick wall like an audio mirror. Any sound going into it will be reflected back at the same angle of incidence. Given that, it's usually best to have your subs as close as possible to boundaries or at least 10ft/3m away so you can avoid speaker boundary interference (cancellations that happen at the speaker due to the reflections).
In the inline gradient cardioid setup, why is the speaker closer to the stage being delayed, and not the one closer to the audience? Is this because the intention is to have the wavefronts sum (and cancel, being out of phase) at the stage position?
Great question! This video goes in more depth on that - ruclips.net/video/e90v1NVT7bQ/видео.html You got the first half of the question right. This recipe creates cancellation in the back, but we do also get summation in the front. The rear sub arrives a half wavelength late at the sub's center frequency (this is dependent on your spacing), but is now polarity inverted, so it flips the comb filter upside-down and has summation throughout the sub range. You just have to be careful and not space them too far apart or the comb filter will bandpass your subs too much. Farther spacing is for systems with lower crossover frequencies.
Can someone help...can I setup the cardioid with both subs on the ground next to each other but pointing in opposite direction or do they need to be stacked vertically?
Super helpful video Michael! But I had a question. I'm working with four subwoofers now, a dual 18 and two 18 inch single subs. I've been placing them in the middle at my events, will it have a similar effect to the two subs being coupled in the middle? I would love some advice about how to place these things for maximum output to the crowd! :)
Two questions: - If you stack subs, is there any positive or negative impact (like more pressure in the chest, ... of the audience)? You did do a 2x2 monostack in your other video. - What if you do angle sub arrays/stacks towards a center point in the audience? :) I often see that in small clubs with L/R stacks. Thank you! :)
If you stack the subs you will slightly narrow the vertical coverage pattern, which could focus the low frequencies a bit more towards your audience. This affect is much greater with a larger stack of flown subs. Angling the subs if you're not doing a cardioid setup or working with a sub with built in cardioid directionality will not change the energy in the center. Low frequencies radiate out omnidirectionally from subs.
I have watched this video a bunch of times. it is gold , thank you! I had a question. for the dual center, side by side Omni pattern and the half wavelength setups, do the same principles apply at a higher Crossover frequency. for example would this still apply for a 180hz cross over with FOH tops on each side of the room/stage and the subs in the middle? and would that cross over point (180hz) be too harsh? the cross over point is common on a popular Column array vendor kit. the cross over point is set at factory and can't be adjusted, but wonder if separating the tops from the subs and setting them up side by side would help focus the low end on the dance floor. thanks in advance. I've been going through your other videos, very cool stuff
Yes, same principles would apply! But do keep in mind that we want the same tonality everywhere. So, you could focus the sub on the dance floor, but you don't want folks standing away from the dance floor to only hear top end, then hear a big tonality change when they walk on the floor.
Hi Michael, great video, just one quick question. I am a mobile DJ, do a lot of school dances, large gyms, I bring 2 Alto 18" subs, I used to put them LR but now I put them together on one side and I have 2 Alto 15" main speakers on top of them. Sound difference from when they were LR of my DJ table is way better. My question is since the students are usually right on top of my table asking for requests, i really cannot set them up cardioid so is this the best set up using the 2 18" subs and 2 15" mains, or should I consider some other arrangement for large gyms? Thanks for the info, I am a lifetime subscriber...
Again, great video. Love using the cardioid setup especially indoor. But. Does this consider ground coupling effect or is it for a system that’s flown?
In this model I didn't have the floor "turned on" as a boundary to have in the predictions. However, you'll still see similar results both with a flown and groundstacked inline cardioid setup.
Thank you so much for your videos! Is there a way in this software that you use, or can you recommend other software, for plotting subwoofer effectiveness in the way that you do here but for inside environments? I.e. the addition of walls and how the reflection from them might cause another dimension of phase cancellation. Thanks again!!
Love the content. The visuals are helpful and I probably need to brush up on my math. I'm in a room similar to your drawings. Our church meets in a 60'X90' room. We have two Subs and four k12.2. How would you place these for best coverage? Any thoughts on drive-racks?
I'd check out these videos for insight on best speaker coverage placement. Long story short, divide the audience in half and have each K12.2 fire down the middle of its own zone. Fly the speakers if you can. If not, get their trim height as high as possible. I'd do two flown center subs, inline gradient cardioid if possible: ruclips.net/video/OeaMtRvIysM/видео.html ruclips.net/video/pNkhxnFNUNU/видео.html And here's some affordable drive systems/DSPS to look at: www.thomannmusic.com/the_tracks_compressors_gates_de-esser.html
Great tutorial thank you, i would like to ask, lately djs and performers prefer to have subs on stage for monitoring purposes, how does having subs on stage affect the cardiod behaviour setup of the FOH subs?
Hi Michael! How do I align phase of side tops with center sub cluster? Should I just put measuring mic in the center of venue and align tops one by one?
Your last two examples, where you are reversing the polarity on one of the subs, show the same level of -27 dB @ 130 as your second example with two subs side by side. I was under the impression that, when you make a cardioid setup by reversing the polarity on one of the subs, you lose about 3dB of output. Can you comment on that please? By the way, thanks for this demo. I'm currently trying to use MAPP XT/3D to duplicate Dave Rat's sub setups and you just taught me to use layers for the different options rather than saving them as separate projects. Also about using the processor to provide the delay and polarity changes. Finally, this video is more realistic for me because I have just two powered subs. Dave's videos are very informative, but he's focused on big boy subwoofer setups so, while I really enjoy Dave's content, it just doesn't apply all that much to my scale of events.
Hey, John. Great question here! Yes, I've "heard" about the -3dB loss in efficiency when running a cardioid setup as well. I've also proliferated this, but honestly haven't not taken a deep dive into figuring out exactly why. So, your question has given me a project to figure out : ) The question in my head is, "This cardioid sub array is -3dB down from what reference?"
@@MichaelCurtisAudio Right. And maybe 3dB isn't that big of a deal? I'm definitely getting better at using MAPP XT, so thanks for the motivation. Happy New Year 🥳
@@johnschalk1271 As long as I'm on a gig with enough subs spec'd to handle what the client asking for I default to cardioid (with the appropriate conditions in place). Max SPL at all costs, as I'm sure you know, isn't the holiest of grails!
You can do it side by side, but it'll change the directionality of the array. If you draw a straight line from the center of the woofer of the rear sub to the center of the woofer of the front sub that's the direction the sound will move.
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I had a left and right set up about 50 feet apart in the church. I use map to predict and saw all the cancellations and the flower petals. So we relocate them underneath the stage a half wave length apart My crossover frequency is 125 Hz I have two subs in the middle touching each other then I’ll spread the others to wavelength apart when I did the prediction again, it look like a gigantic pear. And the energy that the audience get now is amazing so I agree with all this that you’re trying to teach and I appreciate you thank you so much.😊
You're very welcome!
@@MichaelCurtisAudio I wish I can show you pictures of the way it came out.
@@noelbulls8628 My email address is on my website. Feel free to drop me a line there.
@@MichaelCurtisAudio ok thanks
New lessons... Subs in the middle and raise my tops higher. Thank you for this.
You are officially my sound tutor.
I've been using half the subs I used to use and getting the same or even more power thanks to these useful tips. Thanks for the great work and for the metric spreadsheet, very needed for my portuguese workflow. (feet here are only for wearing shoes :D)
You are very welcome. And about time I got around to creating a metric version ; ) I'm glad that's been helpful to you.
This was so helpful, I am just setting up dual subs and ive realised that the cardioid option is the , one I should adopt , as I'm in a brewery and there is a row of tanks behind the stage area, I have built the subs inside two large rum barrels and was going to put them both on the same cradle after watching this they need to be on separate cradles to really increase my options, thank you for explaining things so clearly
There is literally nothing too nerdy or in the weeds for me. Please always elaborate! This has been an excellent intro to setting up smaller systems man!
You're very welcome!
Had a gig with the same subs I have now in the "traditional" LR setup and kept hearing/feeling the alleys/valleys and this video completely visualized what was happening. Going to be using a center cluster with them this next time around and I'm very much looking forward to my walk around, with and without people.
Let me know what you find!
love the content. The spreadsheet shilling does get a little tiresome, but these videos are pure gold. I've probably learned more watching the videos you've made in the past week than I have about sound in months. I'm a 18 year old currently attending college while trying to get more into the event production game. Currently doing events with fraternities and the local area. I'm in charge of sound for our business, so learning more and more about the physics of sound and knowing more about speakers is super helpful.
Glad you're enjoying the videos! I'll have some more varied free resources coming soon. The spreadsheet is helpful to folks, but you're right that I mention it in a large percentage of my videos.
@@MichaelCurtisAudio the spreadsheet is helpful, font listen to this fool
Great video. An additional option I use is to stack the two subs on the left side at our church where the drums and bass are located. Adds a bit of stage location to the sound in the room and when people think the the low end is too loud they can move to the right side 🙂 I happen to be using D & B Audiotechnik cardioid subs which greatly simplifies things greatly
Great idea. And yes, natively cardioid enclosures definitely help simplify things.
Thanks - It shows that you can make big low-end improvements with the most basic setup, without buying more stuff.
Exactly! Even with just two subs you have a lot more control than you would think.
@@MichaelCurtisAudio … so would I do this same center coupling with my two passive Yorkville LS1208 scoops because normally I would do the left & right set up with a qsc 15” on each one inside big ballrooms and it would sound pretty good to me I’ve never center coupled my big scoop’s before but I always couple my powered EV Etx’s and they always hit so much harder!
Somebody please get this guy a bottle of water. lol
Thanks mate, a few videos ago (the one about column speakers one) I asked you which one would you prefer: one double driver sub or two single driver sub, as I was building a small PA. I followed you advise and ended up with two single driver subs. This video is gold for me, I will definitely experiment with the different configurations. Also thanks for the metric version of the spreadsheet!
You're very welcome!
I can't get enough of these videos
Thanks a ton, Nick!
Thank you so much for this tutorial. Wonderfully explained! It helps out greatly for the live shows!
Hi Michael, great video! Can you please consider doing one talking about portable column array speakers for portable dj's as well? Myself and many people I've seen online have doubts in relation to many aspects: they advertise a very good horizontal range like 120º, they almost always pack a small sub like 10, 12 inch (do those pump out enough spl?) and some systems like the maui 28 have built in processors for cardiod setups (would that help dj's), would they be good in a outside scenario. But also they advertise that they can be combined in pairs, so what distance from one another should they be? can we use a different sub with them?
Hope you find the time!
Love your content and the passion towards making your video 😊
Thank you so much!
mobile DJ here. This is amazing. Super helpful.
You're welcome!
Great video, thanks! Probably, aligning the rear sub more precisely in the inverted gradient array would yield to better results. Also, lowering its level a little bit might help
Yes, always verify in the field since the wraparound path from the front sub to the rear will change depending on cabinet depth, etc.
@@MichaelCurtisAudio thanks. I'm currently working on a design for a church where the subs can't be in front of the stage, so I'm considering putting them under it and use a cardioid array in conjunction with bass absorption and detailed dimension of this cavity they would be in. It's a hard one
@@Labaris Cardioid arrays unfortunately fall apart when under a stage. There's too many reflections for the careful conditions of cancellation to occur : /.
@@MichaelCurtisAudio I figured that was probably the case, that's why I was thinking about designing finely-tuned bass absorbers inside the cavity (the space under the stage). But really, it doesn't seem to be a good idea actually. Thank you for your insights!
i have 2 12s in my volvo station wagon. with the back seats down its like a tiny empty room. the bass was best with them both next to each other in the back left corner, instead of one in each corner. only a two foot movement made a big difference.
I enjoyed this video, however, 1. I Wish you would have briefly shown the different frequencies with the last setup. 2. Whenever I've attempted to explain these concepts to any Mobile DJ or sound engineer at that level, I've received nothing but ridicule, ego, and insults on my intellect, and "it doesn't matter."
Hi Michael, I tried different inverted gradient stack configs in Ease Focus 3 and they all seemed to disagree with your delay calculations: They all ended up looking like a super cardiod pattern (in your video 16:43 as well there was a little blob projecting backwards). To mathematically investigate the issue I plotted the sinwewaves radiating from the subs in a math software. My result is that we have two options, a) to go for max summation in the front, or b) to go for max cancelation in tha back. a) is achieved by calculating the delay as described in your video (adding the horizontal driver displacement as a delay the bottom sub) b) is achieved by subtracting the horizontal driver's displacement from the half-cycle of the crossover frequency. In case of 100 Hz that would be 5ms minus the driver displacement in ms). Mathematically we can solve this set of equations for a and b to be true, so we have both max summaton in the front and max cancelation in the back. For this to work, both the horizontal driver displacement and the delay added to the bottom inverted sub have to be equivalent to a quater cycle (of the crossover frequency). For 100Hz that is 2.5ms (or about 86cm) displacement and delay.
Thanks for your video!
Great video sound advice no pun intended. Lol congratulations on the new borne
I'll take it : ) Thank you so much, he's about to turn 1 this weekend.
Bro , i felt like i learn so much waw thank man keep up the great work killer video
dude these are phenomenal tutorials thank you for making em!
So glad i just found you and subscribed, i've been running audio for many years but just with a simple point source system and some home made sub cabinets with a dbx driverack and passive amps (ALL CROWN MACRO K2 and XTI, but i have never really learned the intricate math behind why some shows work and some suck. i dunno if i can do much with just a basic driverack or learn more on how to position my stuff.
You can do plenty with the just the driverack! That unit is more gear towards aligning and tuning crossovers within a single enclosure, not necessarily a full rig, but it can work for that minus any serious output delay times.
Good stuff and well explained.
Thank your for your amazing explanations !!! I have a little question : is it possible to used 2* 15" Sub combined with 1 or 2* 18" Sub ?? I would love a video explaining the advantages and disadvantages =)
I would like this answer too!! I’m in the exact same situation
Thank you Brother, very helpful and great information, keep it up
Great love it, have you done any test comparisons with folded horn configurations?
I've been doing end fire cardioid almost always if I have two subs available... it gives even sound across audience and cleans up the stage and has very low setup and processing requirements.
To do something more fancy one'd need thee or more subs and more processing :)
I hate spaced pair subs that are very common...
Michael. So, as a low end sound guy, could you show what these positions would look like if I had 2 of the QSC cardioid subs… what do the power alleys etc look like if each sub is a self contained cardioid sub? I’ve always seen the dual 12” cardioid sub set L/R with the poles screwed into the sub and the top perched up there… it seems that this use might keep bass off the stage, but create the same alleys for the audience. So good for noise control on stage, but similar issues as single subs spaced L/R for the audience…is this correct. THANK YOU for this content, very educational!
Hey Michael, I think you were speaking to this at the end of the video referencing a 7th setup. But when you delay and flip polarity on the rear speaker in the cardioid setup, doesn't that mean your kick signal will be out of phase? Sure the peaks and troughs will line up, but you'll have a delay between transients on your rear and front sub. Isn't that a concern? or is it less of a concern than not getting the broadband rear cancellation as you mentioned when comparing to delaying the front sub with no polarity flip. Thanks for all your content! Super helpful.
thx for this very nice explanation!
That's a Sensitive mike 5:40 🤫
Need to talk about L+R cardiroid subs more..Your right but 99% that i have to do LR and no other option..
so I have 2 Qsc k12.2 tops and 2 Qsc KS212C subs and i always place them left and right of my dj set up (1 top & 1 bottom) so is it better to put both of my tops on my left & right and both subs facing forward together/side by side in front of me?
How about indoor backed up against the wall 2 sub left right 20 feet apart? Most DJs like me have to put the speakers near the wall...
love the videos
I wish you could do some for domestic home Cinema subwoofer positions and EQ
For now I'm focusing on live setups, but a lot of these principles still transfer. I'd check out Jesco Lohan at Acoustics Insider for small room acoustics and speaker setups.
@@MichaelCurtisAudio I had hoped that was the case so its good to know the videos will translate to a domestic setup 😀
One thing I've done in the past where L/R subs are inevitable is place them so that the main nulls are in the aisles. Still not ideal but better than nothing
Yup, great point! Put the rough stuff where no one's sitting.
What is the best space to a hard wall for a 2 Subwoofer Cardiod - inverted gradient stack? If they are both away from the wall, the best space is as close as possible. But How is the best space, if one is facing to the wall?
Do you have any similar tutorials showing these graphs in a smaller indoor venue with wall/ceiling reflections being accounted for? Are the sound peaks/valleys in a left/right sub config really all that noticeable? For the vast majority of venues we play, it’s the most practical physical setup. Will a cardioid setup against a wall on one side sound all that much better?
the thing I wonder the most about sub setups is how much max spl for most of audience is lost for each setup compared to just putting the 2 together to get that full 6db increase because a lot of times I need to get The most max spl out of my RCF Dual 18”’s because I don’t have enough
Why you don’t consider an ‘end fire’ setup in a situation like that? That’s by far the best config in terms of efficiency, phase response and alignment in the front while allows you to have some rejection in the rear.
End fire is definitely a great option to have in the toolbag. I actually deployed an endfire array just yesterday.
The reason why I didn't include it here is that I rarely have the real estate necessary to do ground stacked end-fire arrays, so have to default to more compact solutions like gradient stack. Gradient configurations also have a more stable coverage pattern over frequency when compared to end fire.
Half wavelength crossover center with JBL SRX828SP (dual 18). Assuming an 80hz crossover, lets call a half wavelength 7ft... where physically would I be measuring from on dual 18s, the center of the box?
The boxes are 47.5" wide, so if placing 2 subs center-stage with 7-foot spacing from their centers, that would mean roughly 3-foot gaps between the left and right sub stacks is the max before the pattern starts to break apart, with an 80hz crossover. Am I on?
Biggest thing I get hung up on with these spacing talks, is there's never mention on where to place the tape measure, especially with wide dual-18" subs.
Thank you very much!
You got it!
cool channel bro :)) keep it coming!! thanks for everything :))
You got it!
great info here.....valuable...👍👍
Thank you!
It will be amazing if u can have guide for small room listening room for multisubs
Next time you should mirror your little webcam bubble so that you're facing the graph on the screen, the way it is now when you're looking at your monitor screen it makes it look like you're looking off to the side of the screen
Great suggestion.
Michael is it ok to run a cluster for FOH in a small venue from one side of the stage
If the stage isn't too wide I'd say it's just fine. If you have a wide stage the low end can feel "lopsided" from an imaging standpoint. I'd test it out - try a LR vs a side stack and see which of the tradeoffs you would rather live with.
Ok will do
Michael is ok to run sub on one side on a stage in a real small church
Great Sub stuff!
Thank you!
Wow great, thanks!
Thank you so much!
How would it work with different sub boxes, two inverted 18" and two front loading 18"?
Hey Michael great video! One question though, at 13:54 you talk about delaying the rear speaker. My brain says delay the front speaker so the sound waves travel together.
Could you explain this!
Cheers from the UK!
Really helpful video, has given me pleanty of ideas for next gig. Just a quick question if I’m trying to utilise a inline gradient cardioid setup. How do I add delay to one of the subs. I’m pretty new to this so might seem like an obvious question 😂. But I’m using 2x Mackie 18s subs and 2 x thump 15a loudspeakers. Would it involve adding delay through a mixer ???
You would need some sort of DSP to do that. You could use the internal prossesing power of an digital mixing console (if that's what you're using) or an external DSP/Speaker management system (like the Behringer Ultradrive or a DBX DriveRack).
If you habe any further questions, don't hesitate to ask, I or the rest of the comunity will try our best to answer...
I hope this helps :)
If working with rear ported bass reflex, how would you calculate using an inline gradient or a stacked gradient deployment? Generally, how would rear ported subs react as a whole in any configuration?
nice clip man! Tx! Looking to aply this info in my mobile Dj setup. tx!
Michael @15:15 you said it was 2.17ft multiply by .88 gives you 1.909ms of delay but then your spreadheet you showed 2.17ms of delay...uh ? am i missing something ?
Hi Michael! So...if the subs are placed up to one half the wavelength of the crossover point (I'm using 80 Hz), you're still able to avoid power alleys and valleys? I'm I getting that correct?
Hey Michael, thanks as always! For the halfwave spaced setup: When you say "up to" the crossover frequency, do you mean by distance or frequency? For example, if my crossover is 80hz, is my spaced limit 7ft? Or can i space them more @ 11ft to boost 50hz?
If I set my subs center either side by side or stacked and the stage is tall (about 5’) and has a brick wall holding up the stage, how does the hard surface behind the subs affect the sound?
This is fantastic! For your personal preference doing smaller shows (400-600 people outdoors) what is normally your go-to setup out of these 6?
Thanks, Evan! I'd say it would probably be the center side-by-side setup. With just two subs having them as closely coupled as possible gets the maximum possible SPL out of the rig. It also gives the widest coverage pattern, which is often needed in outdoor setups.
If the stage doesn't have a hard front and the subs I have are efficient (not needing to drive them hard to get the desired SPL), then I'll do an inline gradient seutp.
Impressive! Question: if you only have 2 sub in a home theater 20’x30x20 (WLH) what would be the response if you put the subs diagonally? That is front right, back left.
You would get some serious power alleys and valleys with them being spread so far apart.
just put 10 boxes 1000W subs per front center, front left, front right, left side, right side, back center, back left and back right. in short, all around. then🤘
What about 12 subs? 2 stacks 6 subs each (left/right)? Treat each stack as a single sub?
Is there more detailed demonstration anywhere explaining cancellation in this setup?
Cardioid Subs Explained For Normal Audio People - ruclips.net/video/EgHK1s7SzIE/видео.html
Cardioid Sub Workshop | Inline Gradient - ruclips.net/video/e90v1NVT7bQ/видео.html
OK thanks, I'll take the time to watch that with thought.
I guess I have had few misconceptions; firstly I thought that back-facing a sub reverses the phase, but it's not dipole speaker... Then I thought delay+distance are mandated by summation frequency wanted, but actually delay compensates the distance. I guess that distance is mandated by summation frequency then?
I'm not able to center cluster my two QSC KS118's (cardioid) because I have a video DJ booth. Is it OK if I put them on one side? My entire setup is no wider than 12 feet. Also, is it OK to cover the subs with a cloth covering to help conceal them?
You are amazing I really appreciate all that you put out there. I'm trying to set up a inverted gradient stack. If your soundboard/subs don't have a built in delay, what kind of hardware would you use if software isn't an option?
Thank you for the kind words, Jefferey!
I'd check out the AHM-16 from Allen & Heath.
Thanks a lot Michael.
I wanna know if its possible to have two different xover points for the rear sub and the front facing sub
Man I Love your content. Just wondering do you have a video for B22 subwoofer Cardiod setup? Thank you God bless
Thank you! Is the B22 a specific model or type of cardioid setup?
@@MichaelCurtisAudio we have a D&B B22 Bandpass subs at church and I'm planning setup like a cardiod setup. Is it possible?
Let's say there is no stage and the band is playing on a concrete pad. Is it still best to do a center sub array if they don't mind seeing a sub or two in the center or is LR the best way to go to avoid looking awkward?
I'm a bit of a dinosaur and have not mixed sound since the Mackie analog boards were popular. Our pastor found out I used to do this and asked if I could help figure out how to add more bottom end to their system. They have a JBL powered subwoofer, i believe its the PRX series either a 15 or 18. The sound booth is situated on the side of the auditorium which I know is far from optimal and the sub sits next to it. After watching your video my question is can one sub work ? I now know we need to move it to the front center but I don"t know if we can rig this to the ceiling. Our only other option would be on the stage center but from what I'm understanding this is not good? The room is not huge and its wider than it is long.
If you're not able to put it center, put it in front of your stage off to one side. Like you said, optimal would be to fly it center. Even better would be to fly two of them in the center and space them 5ft apart of so so you can narrow the coverage.
@@MichaelCurtisAudio Thanks Michael!
Where would be the best placement for one sub inside a bar with cement walls ? Having trouble getting my sound to rumble
I'd try directly in front of center stage on the ground, or even better flown directly in front of center stage.
i recently did an outdoor show. Audience area is size of a football field. I have two dual 18. I put them together touching. had a terrible valley. it was like you turned them off. it was narrow. i started to move them apart and kept checking it. the valley just got wider and wider. it was just dead. we usually do the left right sitch, and have that valley, but not as bad as with them pushed together. my setup did not match these diagrams at all. PS I was right in front of a concrete stage. what gives?
It sounds like to me one of your subs had a polarity inversion somewhere in the chain. They were "fighting" eachother when they were close together because you essentially had a copy of the sound wave coming from the same point in space, but inverted, therefore the sound from your subs was in a silent stalemate.
I was thinking that. They were purchased used. Who knows if some knuckle head "fixed"them at some point in time and reversed the wires. I know this because i had another set and that was an issue. Ill check all my wiring. Doing the same place this weekend again. Thanks for the reply. I really enjoy your videos. I run passive gear. So i don't have fancy built in polarity switches. Lol i guess the polarity built in to x32 would work. When measuring side to side placement...where do you measure from? Ctr to ctr? Outer edge? Where do you get the 5.6 feet?
Can you build a dual 18 with a third facing rear?
I have 2 JBL VRX918SP, can I achieve this inline gradient with a DBX driverack PA+ ?
Could you do an analysis over what the coverage be if subwoofers were up against a brick wall? Also, what would the response be if the subs were about 15 or 20 feet out in front of a brick wall?
Great questions, John. You can think of any hard reflective surface like a brick wall like an audio mirror. Any sound going into it will be reflected back at the same angle of incidence.
Given that, it's usually best to have your subs as close as possible to boundaries or at least 10ft/3m away so you can avoid speaker boundary interference (cancellations that happen at the speaker due to the reflections).
You needed 1.9ms delay on the stacked iso 2.17ms. Outcome sim looked good so it is not that critical?
I'm a little confused by your question?
In the inline gradient cardioid setup, why is the speaker closer to the stage being delayed, and not the one closer to the audience? Is this because the intention is to have the wavefronts sum (and cancel, being out of phase) at the stage position?
Great question! This video goes in more depth on that - ruclips.net/video/e90v1NVT7bQ/видео.html
You got the first half of the question right. This recipe creates cancellation in the back, but we do also get summation in the front. The rear sub arrives a half wavelength late at the sub's center frequency (this is dependent on your spacing), but is now polarity inverted, so it flips the comb filter upside-down and has summation throughout the sub range. You just have to be careful and not space them too far apart or the comb filter will bandpass your subs too much. Farther spacing is for systems with lower crossover frequencies.
Don’t mean to spam but is there any reason to do this for home theater if you want to excite less room modes at say 52hz?
When using "half wavelength crossover center", do you measure from the center of the speaker or is it the length between the cabinets
Center of the woofer from one sub to another
Hey Michael, do you know a brand called wharfedale pro? Any chance you could do a video or review on thier delta range of pro speakers?
Can someone help...can I setup the cardioid with both subs on the ground next to each other but pointing in opposite direction or do they need to be stacked vertically?
Can you run the simulation again but add the bass that is coming from the stage, and see how that sound affects the alleys and valleys?
Are you talking about the bass guitar cab or the reflection of the subs off the rear wall?
@@MichaelCurtisAudio Bass amp on stage
Super helpful video Michael! But I had a question. I'm working with four subwoofers now, a dual 18 and two 18 inch single subs. I've been placing them in the middle at my events, will it have a similar effect to the two subs being coupled in the middle? I would love some advice about how to place these things for maximum output to the crowd! :)
Two questions:
- If you stack subs, is there any positive or negative impact (like more pressure in the chest, ... of the audience)? You did do a 2x2 monostack in your other video.
- What if you do angle sub arrays/stacks towards a center point in the audience? :) I often see that in small clubs with L/R stacks.
Thank you! :)
If you stack the subs you will slightly narrow the vertical coverage pattern, which could focus the low frequencies a bit more towards your audience. This affect is much greater with a larger stack of flown subs.
Angling the subs if you're not doing a cardioid setup or working with a sub with built in cardioid directionality will not change the energy in the center. Low frequencies radiate out omnidirectionally from subs.
I have watched this video a bunch of times. it is gold , thank you!
I had a question. for the dual center, side by side Omni pattern and the half wavelength setups, do the same principles apply at a higher Crossover frequency. for example would this still apply for a 180hz cross over with FOH tops on each side of the room/stage and the subs in the middle? and would that cross over point (180hz) be too harsh? the cross over point is common on a popular Column array vendor kit. the cross over point is set at factory and can't be adjusted, but wonder if separating the tops from the subs and setting them up side by side would help focus the low end on the dance floor. thanks in advance. I've been going through your other videos, very cool stuff
Yes, same principles would apply! But do keep in mind that we want the same tonality everywhere. So, you could focus the sub on the dance floor, but you don't want folks standing away from the dance floor to only hear top end, then hear a big tonality change when they walk on the floor.
@@MichaelCurtisAudio thank you, that make sense.
Hi Michael, great video, just one quick question. I am a mobile DJ, do a lot of school dances, large gyms, I bring 2 Alto 18" subs, I used to put them LR but now I put them together on one side and I have 2 Alto 15" main speakers on top of them. Sound difference from when they were LR of my DJ table is way better. My question is since the students are usually right on top of my table asking for requests, i really cannot set them up cardioid so is this the best set up using the 2 18" subs and 2 15" mains, or should I consider some other arrangement for large gyms? Thanks for the info, I am a lifetime subscriber...
If I put 4 single 18" subwoofers in the center at a distance of 1.5 m or 2 m between them, will they connect?
Again, great video. Love using the cardioid setup especially indoor. But. Does this consider ground coupling effect or is it for a system that’s flown?
In this model I didn't have the floor "turned on" as a boundary to have in the predictions. However, you'll still see similar results both with a flown and groundstacked inline cardioid setup.
Instant Sub 😂
Still the best!
Thank you!
Thank you so much for your videos! Is there a way in this software that you use, or can you recommend other software, for plotting subwoofer effectiveness in the way that you do here but for inside environments? I.e. the addition of walls and how the reflection from them might cause another dimension of phase cancellation. Thanks again!!
There's the full version of EASE, but it's pretty expensive.
Been trying to
download your spreadsheet but to no avail.
I emailed you a new link. Try that and let me know.
Love the content. The visuals are helpful and I probably need to brush up on my math. I'm in a room similar to your drawings. Our church meets in a 60'X90' room. We have two Subs and four k12.2. How would you place these for best coverage? Any thoughts on drive-racks?
I'd check out these videos for insight on best speaker coverage placement. Long story short, divide the audience in half and have each K12.2 fire down the middle of its own zone. Fly the speakers if you can. If not, get their trim height as high as possible. I'd do two flown center subs, inline gradient cardioid if possible:
ruclips.net/video/OeaMtRvIysM/видео.html
ruclips.net/video/pNkhxnFNUNU/видео.html
And here's some affordable drive systems/DSPS to look at: www.thomannmusic.com/the_tracks_compressors_gates_de-esser.html
When measuring half wavelength is this centre to centre of the boxes or is it the actual space between the boxes?
Great question! It's from the center of the woofer of one sub to the center of the woofer of the other sub.
Great tutorial thank you, i would like to ask, lately djs and performers prefer to have subs on stage for monitoring purposes, how does having subs on stage affect the cardiod behaviour setup of the FOH subs?
As long as there's no other boundaries close to the subs besides the stage floor I don't see a problem with it.
Hi Michael! How do I align phase of side tops with center sub cluster? Should I just put measuring mic in the center of venue and align tops one by one?
You should create a paid professional training series.
I have my first course here: www.producedbymkc.com/makingsenseofsound
Currently working on my second.
Your last two examples, where you are reversing the polarity on one of the subs, show the same level of -27 dB @ 130 as your second example with two subs side by side. I was under the impression that, when you make a cardioid setup by reversing the polarity on one of the subs, you lose about 3dB of output. Can you comment on that please? By the way, thanks for this demo. I'm currently trying to use MAPP XT/3D to duplicate Dave Rat's sub setups and you just taught me to use layers for the different options rather than saving them as separate projects. Also about using the processor to provide the delay and polarity changes. Finally, this video is more realistic for me because I have just two powered subs. Dave's videos are very informative, but he's focused on big boy subwoofer setups so, while I really enjoy Dave's content, it just doesn't apply all that much to my scale of events.
Hey, John. Great question here!
Yes, I've "heard" about the -3dB loss in efficiency when running a cardioid setup as well. I've also proliferated this, but honestly haven't not taken a deep dive into figuring out exactly why. So, your question has given me a project to figure out : )
The question in my head is, "This cardioid sub array is -3dB down from what reference?"
@@MichaelCurtisAudio Right. And maybe 3dB isn't that big of a deal? I'm definitely getting better at using MAPP XT, so thanks for the motivation. Happy New Year 🥳
@@johnschalk1271 As long as I'm on a gig with enough subs spec'd to handle what the client asking for I default to cardioid (with the appropriate conditions in place). Max SPL at all costs, as I'm sure you know, isn't the holiest of grails!
Thanks Michael - Can you do inverted gradient side by side? Or must it stack?
You can do it side by side, but it'll change the directionality of the array. If you draw a straight line from the center of the woofer of the rear sub to the center of the woofer of the front sub that's the direction the sound will move.