Overcoming Boomy Rooms In Live Audio (With Minimal EQ)

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No one likes mixing in a low end swamp. Even though we often can't change the acoustic properties of a venue, we CAN change our stages, our speaker placement, system tuning, and mix decisions to create a clear consistent mix in any venue.
Today we'll cover twelve software buckets including:
Why EQ is the last tool you should reach for
How the physics of room modes actually work (and how that affects your PA decisions)
What to eliminate from your stage
How to avoid low end buildup
00:00 - Intro
01:53 - What is the root problem of "boominess"?
07:19 - Does carpet help?
09:39 - Strategy #1, Reducing The Number of Sound Sources On Stage
10:44 - Strategy #2, Prioritize High Frequency Coverage Over EVERYTHING
14:14 - Strategy #3, Steering Low End Effectively
16:00 - Strategy #4, Shaping Low End EQ On PA and Channel Processing
20:22 - Outro

[@yourmom5930tehe]

“Do not try to be an acoustician on site with your sound system” made me laugh so hard haha. Sometimes doing warehouse raves I have the biggest challenges, thanks for the great video.

[@wienerstein2817]

Dude I just found your channel. So many jems.

[@MichaelCurtisAudio]

Thank you so much!

[@raminhajipour6490]

Hi Michael, I'm so glad to see your channel! I was wondering which of your videos deals with managing low-frequency room modes in large spaces?

[@jithintom94]

Placing the speakers tilted slightly down is also something i tried that worked as well. Keeps energy off the walls..

[@scandinavianserialki]

Thanks for this video. I'm doing a show in a church with a high ceiling on Friday. I really wish I could set up delays but I basically have no budget and I'm working with an analog mixer with no way to delay.

[@MichaelCurtisAudio]

You're very welcome! Yes, you're in a tough situation. Do you have access to any speakers like a K12.2 that have delay processing built in and you could add the delay at the speaker?

[@gabryga76]

I play in a rock band and we do a lot of live shows, always indoors and in small places (pubs). We have 2 heads of 15 and we usually use 1 or 2 subwoofers (placed in the center). We ALL go live into the PA (3 guitars, 2 voices, 1 keyboard, bass and drum kick). In all instruments we cut the bass heavily except the bass guitar where we cut down to 60-80hz.(12 db for octave) In small venues, in my experience, all frequencies up to 60-80 Hz (except for the kick are useless), we have the 'punch' of the bass on the second and third harmonics.if I turn off the heads, only the kick and the bass guitar come out of the subwoofers (crossover 100hz). I understood that the low subs, in rock, are just a problem

[@calvintraviserickson]

I do sound for small breweries in town and bands that like my style of mixing and speaker deployment. I have only known outside side and indoor, "boomy" cinder block, glass, cement sound . When processing the speaker deployment, I'm not able to run pink noise because patrons would just leave immediately. I tend to tune the mains that are up 9' or whatever and side fills by ear very quickly to a spotify track. I almost always am ducking around 250Hz, or around 400-670Hz. In the last year those narrow cuts I used to make are now less q and less cutting, I try to make a more glued together sound . This ties into your video on how the low end may most likely need some attention also, ie not running a sub aux. Now I do run a sub matrix that is not affected by the main mix eq, but I have to be very vigilant in determining where exactly the good part of low end and where low end buildup is happening. I'm almost always doing a low shelf or reducing the amount of 34Hz I'm putting out. 80Hz is also a huge factor in a bar room, being the octave up ish from the main culprit. Thanks for your informative concepts shared in this community, I take what I know and compare, and it makes more sense in the end. Don't be afraid to bend rules in that subs on aux not being valid thing though, bass is king.

[@MichaelCurtisAudio]

Thanks for sharing your approach! Yes, low end and low mids are always tricky in untreated smaller spaces. And yes, I know plenty of engineers who run their auxes on a sub and still get great results.

[@bruceusven837]

Great Video!

[@MichaelCurtisAudio]

Thank you, Bruce!

[@ladjkaoz]

Im glad i wasnt so blind in this topic.

[@tomehCanada]

How about adding fills along the audience with the correct time delays to align with the mains while reducing the mains level? At low levels and aiming at the audience for absorption?

[@mojoemurphy]

Yes, the SVT, the only amp I ever bring, with the full 810. It brings the speakers up to near ear level, instead of blowing air past my calves. It also is rather mid range focused (for bass) and it's like a Ferrari, it can go crazy fast (loud), or nice and easy (very reasonable). I almost always need to run through my subs and mains even in smaller clubs because I'm just loud enough to stage monitor. I'm also not afraid to monitor from the side as to not mess with FOH (that I'm running from stage anyway)

[@MichaelCurtisAudio]

Great stuff. Not to mention SVT's just sound killer. Love that you're aware of how your stage low end affects the room and mix!

[@SalvadorEguiarteDG]

Thank you Michael! Excellent video. I have a question though. Where should I put the OC 703s?

[@MichaelCurtisAudio]

Short answer - everywhere : ) You want it to be thick. A 6" deep panel with a 6" air gap behind it will get you damping down to ~40Hz. Jesco Lohan's KZbin Channel, Acoustics Insider, has info on this.

[@SalvadorEguiarteDG]

@@MichaelCurtisAudio THANK YOU!!!

[@MichaelCurtisAudio]

@@SalvadorEguiarteDG You're welcome!

[@tony8236]

hi Micheal. about the front fills are you looking for the coverage crossover to position them? or do you decide that the foh reaches for example 10m and you can place the front fills without considering the foh coverage?

[@MichaelCurtisAudio]

Front fills are 99% of the time going to be resting on the downstage lip of the stage, or built into the stage, so that determines their placement. What determines how many front fills I need is the coverage angle of those front fills, the total horizontal distance they need to cover, and their throw distance to the first row. You can calculate that on row 87 of my AMSS. Bottom line, you can have your front fills cover twice the distance that they're throwing to the first row of your audience when it comes to vertical coverage. So, if your front fills are throwing 4m to the first row, I can expect their coverage to "expire" at 8m, then the mains will have to pick up after that. This obviously subject to your front fills being high up enough to shoot just over your audience's heads. If the mains are already covering up into the front fill's normal coverage zone, I'll just turn down the front fills until I get an even exchange. Just having something close to the stage to help the listener image downward toward the stage is helpful.

[@tony8236]

@@MichaelCurtisAudio I work with hdl20, foh and front fills, 100° on specs

[@MichaelCurtisAudio]

Very cool. Looks like if you had those boxes throwing 10ft to the first row, they would cover 20ft into your audience and you'd place the boxes 15.32ft apart. Then just add as many front fills as you need horizontally to get the desired width.

[@gerryhotson1880]

Hi, I do small sound production and only have 2 15inch subs. Most of the time they are full out so I can't afford to lose any SPL. Does using a cardioid sub setup sacrifice SPL for better steered low end? Thanks in advance for any input

[@MichaelCurtisAudio]

It depends on the specific cardioid setup you're going with, but you can expect up to a -3dB drop in level in some cardioid setups. To get the absolute max SPL out of just two subs I'd place them butted up right next to each other in the center in front of your stage.

[@DallasSoundGuys]

I put the subs on the M/C. No mics sent to that (per channel). Thoughts on this vs. Matrix?

[@MichaelCurtisAudio]

I still prefer Matrix because if I apply any master bus processing to my LR bus my subs also inherit that downstream. If you send individual channels to your M/C, but then have a master bus compressor on your LR Bus, the M/C isn't processed the same.

[@JuanJose-wt5yj]

Thanks for the video. I see that in your room you have acoustic treatment. Can you explain what you have? Do you have measurements of it? It is to see the acoustics of your room by seeing the Waterfall, RT60, ETC, Spectrogram, etc, etc written with translator Greetings

[@MichaelCurtisAudio]

Hey Juan! Thanks for the question. I used to have that data, but have since lost it after moving into this studio space. What I CAN show you is the frequency response at mix position, though. I'm using mostly GIK Acoustics Monster Bass Traps. I have a few of their soffit bass traps in the corners as well. drive.google.com/file/d/1u2qLHr6TOGJPNqYVYJVb4fqpwOJ_kSdP/view?usp=sharing

[@JuanJose-wt5yj]

@@MichaelCurtisAudio Thanks Michael for replying and for the link. to drive To date, I pay particular attention to the treatment Acoustic of the rooms, if in the future you can make a video about your current room it would be very good and thus be able to see what work your GIK Acoustics panels and traps do. Greetings

[@MichaelCurtisAudio]

@@JuanJose-wt5yj You're very welcome! I've been very happy with the GIK acoustics stuff. I'll keep that in mind for a future video.

[@JuanJose-wt5yj]

@@MichaelCurtisAudio I will be attentive to your channel in case you make a video of the acoustics of your room.

[@sendalunar2974]

Thank you. I play every Friday in the boomiest venue in town. Also the smallest . But I'm no sound guy so here I am watching your video hoping that tonight sounds okay hahaha thank you!

[@sendalunar2974]

So before watching this video i wasd gonna bring my bass amp. So i guess i can just do DI

[@MichaelCurtisAudio]

@@sendalunar2974 You can totally bring your bass amp, just run it low enough where the audience isn't hearing it. Just for your comfort on stage!

[@sendalunar2974]

@@MichaelCurtisAudio good advice thank you!

[@MichaelCurtisAudio]

@@sendalunar2974 You got it!

[@66fitton]

You look way too young to be this well informed lol! I'm looking forward to testing this stuff out in the shop over the winter. I do some big outdoor ribfest shows in the summer. I have 4 single EV 18's, two double EV 18's and two Elite double 18's. I used to just pile them all up on each side and smash people with 'em lol. I realize I have way more options than just that. The four singles across the front spaced properly would probably sound better alone lol. Thanks so much for this stuff!

[@66fitton]

Do you have any recommendations on how to utilize the above mentioned subs together all at once? I had thought of the four singles across the front and the double 18 cabs out at the ends. I'm wondering what the pros and cons are of having subs everywhere across the front. The stages are usually 40 feet wide and outside. Any suggestions? Thanks!

[@MichaelCurtisAudio]

@@66fitton Hey, Steve! Glad this was helpful. I'd check out this video of mine on using multiple subs on the same gig, then come back with any questions you have - kzbin.info/www/bejne/h2XRqmpmaNpgodU

[@jttech44]

Why use a low shelf when the problem is basically gone at 66hz or so? Wouldn't that harm reproduction of the very low frequencies? Or was it more that it was too loud down low in general and because your measurement coherence was sortof all over the place down very low that you just used your ear instead of relying on maybe bad numbers?

[@andyevans2336]

The best reason to cut low Freqs is that the only valid sources for below 150 hz are typically bass, keys and kick and maybe some floor toms. The only things the rest of the mics are picking up is non valid audio ( floor stand boom, random bass waves, etc ). The only time that I even considered lowering the hi pass on a vocal was with the Oak Ridge Boys for the tune Elvira. And for fun, I added his voice to my subs. Great fun!

[@jttech44]

@@andyevans2336 I tend to be pretty liberal with the high pass on keys as well if the band has a bass player. Gives the bass some room to play in. For the stuff that needs it, I split the keys and cut/keep the two sets of channels at 200hz, then side chain the low side to the bass directly. That way the bass smashes out the low end of the keys, but when the keys are carrying it and the bass is quiet the low end is there. More of a studio trick, but works well live if you have the channels.

[@th3bigred21]

why not use the mono send for subs