5 System Tuning Mistakes Worth Avoiding

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Want to learn from my five biggest mistakes in the field?
All of us experience growing pains when learning any new craft. Today I want to help you avoid a few system tuning speed bumps.
We’ll cover:
- The biggest step everyone skips
- How to not screw up your mains to sub crossover from the start
- Where I place my microphones for line array tuning
00:00 - Intro
00:39 - Skipping Verification
04:24 - Mindless Mic Placement
09:31 - Parametric Pulverization
13:02 - Doubling Up Crossover Processing
15:37 - Toolset Unfamiliarity
18:52 - Recap

[@pedrodyck95]

Just a couple of months ago I didn't know about live show tuning but I've watched all of your vídeos and it helped me so much, recently I had a tour and be able to get every auditorium at the same frequency response and getting good coverage, and knowing where to place speakers and subs was sooo good, I just appreciate your vídeos a lot, I've learn all that from you, thank you.

[@MichaelCurtisAudio]

So, so glad to hear my videos have been helpful to you! Keep learning and putting this knowledge to work.

[@TickleFingers]

I think your coverage of the EQing and the whack mole analogy was great. I think that your outline of what would be the best approach is one of the best I've heard. It really drives home the point in a very easy to understand way. I'm going to share this with some others that might benefit.

[@MichaelCurtisAudio]

Thank you so much!

[@lhenn_]

Hi! I'd love if you could measure and tune a 2.2 or 2.4 system, which is used by bands, DJs, ... from scratch and show, what you are looking for, what things you ignore, what things you take care of, etc. That would really help! :) Thanks!

[@googleantispy3850]

Another great video Michael - much appreciated. One expansion on crossovers... when I built my first mix room, I naively assumed that I could rely on the "natural roll-off" between mains and subs to do that job. Ha! Could not have been more wrong -- "mechanical" diminutions of spectrums in speaker systems are neither linear nor reliable. But I was reluctant to add more active electronics in the signal path. This was a mix room seeking the purest path possible. I finally found a basic electronic crossover, identified its numerous sonic problems (not from design but rather the cheap parts budget), did numerous upgrades to make it sonically transparent, and the final synergy of sonic improvements was remarkable. Overall crossover lesson learned. :)

[@MichaelCurtisAudio]

Thanks for sharing that! Glad you enjoyed the video.

[@MichaelNatrin]

Great video & info!

[@MichaelCurtisAudio]

Thank you so much!

[@aaronsase]

Hey Michael. Thank you for your dedication to these videos. How does lowering the high frequencies in each box relate to the data that was shown in the software?

[@DustinRadtke]

I'd love to see you do a video on your favorite vocal mics. Wired and wireless. So much debate on Sennheiser vs Shure. Also how to tame them. I don't know why but our wireless mics seem more feedback prone even if we don't move around a lot.

[@fierybones]

Thanks. Good video!

[@iMilletos]

Thank you, your material is very helpful. My main problem when taking measurements is poor coherence due to reflection from the walls or the ground and bad data. I have only one measurement mic at the moment and when I have to measure a room, I usually take a lot of measurements in advance and when I have to measure and calibrate a single speaker outdoors, I find the most useful method is to put it on a tall speaker stand, raise it at the maximum height and I put the microphone at about 2 meters at the same height. It actually gets rid of the floor reflections and the data is more useful. The method you showed at 2:50 just didn't work for me. It usually gives me more LF content and has a huge dip around 500Hz or so, depending on the distance of the mic.

[@MichaelCurtisAudio]

I'll have to give that a shot!

[@perikodiff]

Hello, if you only have time to do a single measurement, would you put the microphone in the center where the conttol foh?

[@SuperMcgenius]

Good advice

[@soundman1402]

That parametric pulverization is something I've encountered when mixing music in a studio setting, too... I would try to use it to pick out every little thing that bothered me in e.g. a vocal performance, and by the time I was done, the track sounded terrible. I bypassed the EQ, and suddenly it sounded better. Lesson learned about making the parametric EQ look like it was hit with a cheese grater.

[@MichaelCurtisAudio]

It's so easy to sucked into being too granular, isn't it?

[@OtherTheDave]

I’ve found that careful use of dynamic EQ or multiband compression (or both) can help in those situations.

[@chris816cc]

Thanks for the vid Michael! I’m often working with function bands where I have about an hour for setup and tuning so I’ve been using an FFT on my iPad (not ideal, I know) and quickly making it sound good to my ears. I’m curious if you have any tips on how to make my process more consistent without needing to bring an interface, comp, etc. Thanks again!

[@MichaelCurtisAudio]

I'd say be intentional with where you take your measurements from, even if it is from a simple RTA. Make your judgements in mic positions that will affect the most amount of people. Focus on getting a great design, speakers in the right spot, etc. What an RTA will not tell you is the polarity of the speaker, so may be worth it to check the gear outside of a show environment so you're not fighting yourself.

[@ghighrolla711]

good video, should have mentioned the importance of taking off axis traces as well.That data is crucial to making sure everyone gets the same show. cheers

[@MichaelCurtisAudio]

Great point. Thanks, Scott.

[@nickevansaudio]

I thought that one of the examples in Mic Placement section showed 4 mics measuring Main R (inbuilt speaker in the wall) and checking coverage / tonality from front pew to rear pew? I would imagine 2 / 3 of those mics would be OFFAX. Am I right?

[@MichaelCurtisAudio]

@@nickevansaudio Great catch, Nick. Yes I did have some OFAX measurements in there!

[@macfmradio1694]

Hello sir i would like to learn more with assist you is there any chance to offline with you ?

[@nickevansaudio]

Hi Michael. Thanks for the vid. Hope you managed to make the S2N Hard Rock for 200th episode yesterday! Quick q - in the example where you were placing 3 mics ONAX with the 3 box VRX array MAIN R, how did you work out where to place those mics to ensure they were indeed smack ONAX for each box? I am personally trialing Meyers MAPP 3D which can give you your centre lines for each box and thus the exact co-ords for mic placement. Do you do something similar before an SE gig, eg using maybe a JBL SD equivalent s/w or have you trained your eye to know exactly how to get right ONAX for a box that is flown? Thanks in advance.

[@MichaelCurtisAudio]

Great question, Nick! I personally haven't found a huge different in the measured response on "eyeballing" it vs calculating exactly the ONAX position. Although I do believe being precise is a huge part of our job, moving quickly is also important. So, for me personally spending 30 seconds eyeballing each mic gets me close enough to my desired results.

[@nickevansaudio]

@@MichaelCurtisAudio great ok thanks.

[@samankumara7404]

Good sir

[@jrules209]

Hey man, love your content, getting lost in the world of sound and its complexity, can you do something for some sort of simple setup, I am limited with gear. I have 2 JBL PRX815w's, soon I will be adding a PRX818 sub (if I can find one, if not a prx918) and I have a Behringer X-Air XR 18, and that is it no other fancy processors or mics for reading levels just simple and straight forward! I cannot use the PRX Connect app with my 815w's being as JBL has stopped support for their app working on modern Android OS... Challenge given lol.☠

[@MichaelCurtisAudio]

I'm happy to help, but need more context for the type of gigs, expected coverage, rigging requirements, etc.

[@rolandomota7474]

What speakers are the white ones flushed in the walls of the sanctuary?

[@dansantoso48]

Can you make guide for making xo in dsp for listening room hifi? Do u do it on axis about 5x driver diameter or at main listening position which is off axis? Thanks

[@rolandomota7474]

Michael , can we use REW for doing the tests?

[@MichaelCurtisAudio]

You absolutely can, but it's an "offline" measurement, meaning non-real-time. You perform a sweep, then look at the data, change something, do another sweep, look at the data, etc.

[@nunojorgenjstudio7954]

The hipass is to save the amp from handling frequencies that the speaker doesn't reproduce, thus saving precious wattage for those that really need it. At least that was what I was told. But yeah, that applies to a passive subwoofer system, active systems are supposed to have that covered.

[@soundman1402]

The high-pass can also save your woofers from over-excursion when trying to handle bass below the cabinet's tuning frequency (where the cones become unloaded and flop around, producing no sound).

[@nunojorgenjstudio7954]

@@soundman1402 absolutely.

[@MichaelCurtisAudio]

Yes, if it's a passive speaker with no processing in front of it then by all means use the necessary filtering to protect the speaker from over excursion and create the necessary crossover to the mains.

[@c.s.5177]

Should you tune the system with the subs on?

[@MichaelCurtisAudio]

I usually start with the mains soloed, then subs, then both combined.

[@CarlBurnss]

Have to say, the interface of smaart is pretty vague. Since I don’t use it often, I have to search a long time for the simplest functions, really frustrating And I suspect smaart of not detecting 360 degrees out off phase problems sometimes

[@MichaelCurtisAudio]

Different workflows and tools for different folks, for sure. But I will say it's hard to be familiar with tools that aren't used often. I'm not sure what you mean by your second point?

[@conorm2524]

If the source is 1 cycle early or late, with reference to an existing trace, it will show in the steepness of the phase graph.

[@ajemerson8238]

If it was me. I wont do per box IIR FILTERS..😆😆 If it is an FIR filters it's fine. But not IIRS

[@MichaelCurtisAudio]

Sure, FIR would get you less phase change. But a +6dB IIR high shelf still has max +30° phase change at the corner frequency, which is still 92% out of the total 100% total summation you could get out of two adjacent boxes at equal level. Rarely is there a 6dB discrepancy between two boxes, so the phase shift would be even less and summation would be more like 95-96%.

[@jean-lucbattista2492]

That's the worst case scenario, if both speakers had the exact same phase. Sometimes the eq correction can pull the phase in the right direction too.

[@OtherTheDave]

20:00 “Complementary EQ”?

[@MichaelCurtisAudio]

Complementary EQ means that the phase change of the same filter but a cut or a boost are mirror images of each other.

[@okay1904]

too much talking. But good points

[@MichaelCurtisAudio]

As opposed to?

[@knelson1180]

Just my humble opinion, but you could save alot of time by playing source material and use your ears to tune the room. All that data and most times you could tell which frequencies are problems and where. I suppose if one is inexperienced, relying on measurements would be a good starting point.

[@MichaelCurtisAudio]

Playing familiar source material is a great way to verify your measurement work afterwards, but there's plenty I feel that measurement material does not tell you about a PA. Even the best ears couldn't tell you which of a single box in a line array is polarity inverted. Using measurement doesn't mean you're inexperienced, it just means you're starting with data, then verifying those measurements and tweaking them with your ears.

[@XIIMonkeysMusicGroup]

Measurements also give hard concrete data for boards of directors too, who don't believe ears, but do trust numbers!