Main to Sub Crossover Alignment Fundamentals With Open Sound Meter | Pt. 1
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- Опубликовано: 3 авг 2024
- ►► Get this OSM Project File free in my audio tools: www.producedbymkc.com/audioto...
Trace-book.org - trace-book.org/
Main to sub alignment is one of the most highly requested topics I cover on the channel. Why is this? My take is this is one of the last crossover frontiers we as audio engineers IN THE FIELD have control over. Everything else is handled by the manufacturers in the boxes. No longer are we soldering our own passive crossovers to hand off mids to highs. Subwoofers are their own separate box, so we've got to take care of business.
Today's video removes many of the variables that muddies the waters when it comes to Main and Sub alignment. We're focusing on the fundamentals of the physics of sound and how it affects getting summation (energy working for us) throughout our crossover range (where our mains and sub overlap).
We'll cover:
- How you should prioritize this process among how else you can optimize a system
- My favorite features in OSM
- How to zero in on the exact frequency range for optimal alignment (and it's not always the where the crossover filters are set)
⏱ Timestamps:
00:00 - Intro
01:41 - Setting Up Your OSM Session From Scratch
05:57 - Defining Success & Speaker Processing
07:33 - Alignment Procedure Step by Step
17:59 - Key Takeaways
#subwoofers #livesound #opensoundmeter #fft 
Видеоклипы
Is there a part 2? I ask because you finally start to explain things that I can understand after listening or reading others for many years.
I have been looking forward to this... Thank you so much
coolest explanation of something I've always understood in real space
Can’t wait for the field video! Thank you so much for providing such great information. It’s helped me out in my volunteer work.
Thanks Michael! Cant wait for part 2
I was waiting for this! Thanks for your precise and very visual explanation!
Best channel concerning audio and PA system processing on the net!
That's very kind of you! Glad it's helpful.
Looking forward for the next episode!
Thank you for all this precious information! Keep it up 💪
Very balanced view on a contentious topic. Well done!
Thanks a ton, Ben!
this is very thorough! thank you Michael!
this was amazing, thank you Michael
This channel is amazing. Thank you
Great video Michael! I'm just getting started on learning about this, so this is perfect timing.
Pun intended!? haha
Indeed.
Perfect timing and well aligned with his position.
@@FOH3663 haha, I love it! I can't believe I didn't notice what I was saying!
I really want to use these techniques for a gig coming up soon. Need to get a PC, get OSM and learn how to use it. The information here is helpful. Thanks.
Great tips. Thank you so much.
Useful information. In the pursuit of perfection I'd like to do this but rarely have time to get any tuning done. I'm doing small stuff, nothing this big.
Thank you for the excellent lecture. This material is very helpful, especially since such resources are not readily available in Korea
Question:
1.Is the reason for using the Butterworth 10th filter without the LR filter to be close to the target trace?
2. Where would you place the measuring microphone in a space that can accommodate about 300 to 500 people? Because the phase is measured differently depending on the location
3.Measuring the delay caused by the distance difference between the measurement microphone and the subwoofer is quite challenging. How do you address the delay measurement between the microphone and subwoofer when measuring the subwoofer?
Loved it, ill be the honest one, I understood 50% but loved it anyway.. I think you need to do a dummies version..
I second this lol❤😂
You're GOLD
This was great. Very helpful. I do have a followup, though. Everything you're doing to shift curves (add gain to the sub, for example) in OSM...how do you then translate this to a live rig? In other words, now that you know that you had to bump the sub up +9dB to reach your target trace, what does that translate to once you start setting up the rig at a new venue? Or do you just have to re-measure once you get there, do pink noise and look at the RTA?
Looking forward to Pt. 2!
Thanks 🙏
genius!
Awesome video, Michael! thanks for sharing such a great information. Let me ask you something. I have a 3.1 system, I mean 2 subs and 3 tops. At the moment the tops are running Left Right Left, because I don't have any audio processor, what's the best configuration you think i should have? I've been thinking on the dbx drive rack to divide the signal and get L C R, but you think is it worth? the place is not big, is a medium size church.
Great Videos , very informative and a valuable resource..Thank you!!!
Shame i can't get open sound meter to work on my M1 Mac Mini (monterey 12.6.7) Have been through your vides and all the settings numerous times to no avail. For whatever reason, the audio input isn't being picked up by OSM. Signal generator outputs to my speakers, have had it looping back to an input successfully, also tried an external signal generator. Sound card and speakers are fine, just no audio is getting 'inside OSM' as the meters are not lighting up at all.
This is so good!
Thank you Michael 🙏🙏🙏
Specially with the added benefit from using open source apps.
May I ask your opinion on room eq wizard REW for this task.
One big adventure is that there's no need to blast pink noise on the people working in the venue.
I would to see one of your videos using REW as well.
Thank you!
Thank you very much!
I don't think there's a need to blast pink noise either. You can see in one of my earlier videos that you really don't have to run your signal generator very loud at all to get coherent data. And you only need a few seconds of pink noise going for each measurement.
Greetings Michael! Thanks for the video. What if we need to allign main satellite hang with a front fill speaker, what frequency crossover region should we look for?
Thanks Michael, great video as always 🙏
When you're defining the 10dB window you are doing +-10dB isn't that a 20dB window?
Great question, I should have used better terminology there. It is indeed when any signal is either plus or minus 10dB of a reference that we care about their interaction.
This was super helpful! Thank you so much!
I replicated this and was goofing around. What do you think of inverting phase on the KW153 and then delaying the sub 10.6ms. The phase looks pretty good in the crossover region and the delay is less than using the other method. The summation might not be quite as good but looks pretty good.
please do part 2
My brain is now toast! I need a personal mentor. 😩
I'm sorry if my explanation was confusing to you. I was only reference Smaart because that's what I usually use and many engineers are familiar with it.
Yes, you can use an external driverack for crossovers if the speakers have no processing.
The mains is where you set your delay locator for timing, then adjust subs to match the phase.
@MichaelCurtisAudio qsc k12.2 I believe most of these active speakers have internal processing. But what if I have it set on full range that's bypassing the internal xover right?
I've been using the driverack on these k12.2 and a couple of junk jbl prx 518s 18" subs. Can all these speakers with internal processors somehow be bypassed?
I've been helping out this club for free and I've been donating thousands of dollars 💸 just to keep the rock n roll alive.
Thanks for all your help MichaelCurtis. Sure wish I could find a mentor like you just for some basic tunings. Mixing I have no problems with. Been Mixing since the late 60's.
Where can I download that MLAWRENCE target trace you use for OSM?
I took your advice to practice with OSM before moving up to purchase smaart 9.
Where or when is part 2?... it's been 10 months since you uploaded this part 1
also wondering if it will ever be released...
Hey Michael. Is the Michael Lawrence trace your favorite to tune to? Is that available somewhere? Thanks
Any advice for swapping between soundboards when mixing different venues? I have a chance to mix for a band at a different venue than my main gig but I’m not exactly sure how to work with different systems.
great video Michael. Can I ask what is the lowcut of kw153, 100hz or 80hz? Thanks
Thanks! It's 100Hz,
What's the proper procedure in tuning a 3way system, horns, mids, subs? I'm assuming you time align horn to mid pre eq or post eq? And mic placement , vtop since waves are much shorter? , onax 50%, onax 75% same as subs?
Hello ! I am using OSM on mac and Smaart aswell. Infortunately I can't get proper data with OSM ... with the same volume from the PA and same gain on the mic, i get a proper trace on smaart but very blurred one in OSM ... I use the same time reference aswell.
What is happening here ?
Hello. Where to place the mic for a mono sub and stereo foh. Thanks.
That is quite a lot of delay. Would have liked to see you use phase flip on the sub, and then delay. It might have required less delay then.
Like I explained before manipulating the data, these two measurements were not taken at the same distance or the same delay locator setting, so the relative timing offset between the main and sub at their starting point is irrelevant. I'll do another video on what things look like in the field.
@@MichaelCurtisAudio I hear you 100%, but it could've been a nice demonstration of what one might need to try in the field, if you were to find such big delay values between mains and subs. But I also understand that this was just an informative demonstration about the concept. Please keep them coming!!
@@christiaanbezuidenhout6984 Yes, totally makes sense. I do plan on covering in future videos what that looks like in the field.
So do you recommend the Michael Lawrence curve or the L Acoustics curve? I just got done tuning all my systems in my different rooms with the 1000hz tilt curve because I thought that's what you would do haha
I used to use the L-Acoustics curve, but as of 9 months ago or so I've switched to Michael Lawrence's curve.
@@MichaelCurtisAudio can we get that curve from somewhere?
@@MichaelCurtisAudio
You read his book?
Thoughts/revelations?
Good gravy, I am in over my head. Have you done this for a KS118 and HDL6A combination?
@MichaelCurtisAudio
I have! They work great together. Just apply a second order (12dB per octave) Butterworth high pass filter to the HDL6-A's, no other processing needed on the KS118. Then time align them in the field to where you want to have them sync up.
@@MichaelCurtisAudio Sweet, 80 or 100 Hz?
@@garyjenkins9169 100Hz! Sorry, forgot to include that.
So are there tracebook files that can be transferred to smaart?
6:23 When you turn up the gain in OSM, does that mean you have to take note of the value and apply that in your console?
Only the relative gain will be important. So if your subs are at +10 and your mains are at +4 to get to your target curve, you really just need your subs +4db over your mains. It's not color by numbers mind, you'll need to gainstage properly, but you will get the offset in OSM. Generally speaking, running something at 0db is good practice, either your subs or your mains, and then run a negative offset for the louder source to hit your curve. That'll maximize your available dynamic range.
Would it be viable to use a sine wave in the field if you dont have access to a laptop and software? Set cross over points on both mains and subs the same then play a sine wave through both set at equal volumes with the phase reversed on the sub and start implementing delay with the sub being closest to the reference point?
I can give you a tentative yes to that technique aiding with some alignment, but it's possible to be "in phase", but "out of time". You could get lucky in that you have phase overlap between your main and sub at a single frequency, but not have them across the rest of the range of overlap.
@@MichaelCurtisAudio Thanks!😊 appreciate the help👍
I have this exact set up. Normally it is 153 on pole in the 118. Although I really want to try subs in the middle and 153 on stands at some point.
If I understand correctly from your example you'd set the delay in the mixer for the subs at 13ms. Isn't that noticeable to the player? Like the kick or bass would feel off to them as they play and hear it in the sub or is this short enough that it isn't audible to them?
Hey, Dustin. Great question. You're right in the example I did have to delay the subs 13ms to get the traces aligned, but these two measurements were taken in two different environments at different reference settings and different distances. In hindsight I should have taken the measurements with the speakers together at the same place.
In reality the alignment deltas with the KW153 and KW181 on the same horizontal plane would be very, very small.
You wouldn't feel 13ms. Casual perception threshold is around 100ms, musically you'd probably notice it around half that but wouldn't know what it is. For reference, at 120bpm, the preferred dance music tempo, a quarter note is 500ms, and it halves down from there. Really really good drummers can probably manage to hold a 1/16th note at that bpm, which is 125ms, so you can see how tens of miliiseconds aren't likely to get noticed.
Do understand of course, that's only the PA's latency, digital mixing/processing/etc also has some amount of latency as well, and it's cumulative, but even if you're adding 13ms, your round trip time is probably under 20ms, worst case, which still won't be noticeable.
Tem como fazer um vídeo de como calibra o open sound mete ?
Sir Michael,
Since I'm not using active speakers with no gain knob to set at unity, and no processor like yours. For systems tuning how do you properly set up gain stage using OSM, with passive speaker's, Crest 9200's for power, a dbx driverack for processing sending the pink from OSM to my M32?? That scenario wasn’t taught in workshop. Hoping to hear back from you soon. 🙏
I would find the manufacturer of your speaker's recommended DSP settings, apply those within the dbx driverack, then run the AES75 max spl test to determine at what SPL and drive level the system goes into limit. Once you find that you can adjust your power amps and/or output drive from the processor to find the "volume" sweet spot.
@MichaelCurtisAudio Man that's Greek to me. 😆 OK you'll just have to make a trip to San Diego and hang out and enjoy for awhile.
I always have a tough time finding top secret specs like that. aes75?
Funny I'm running an aes from the stagebox to the driverack.
I'm going to need some help on this one or I'll just have to fake and wing it. 🪽
@MichaelCurtisAudio For the mains I'm using a pair of full range EAW LA215
Four jbl 2241H loaded into four single horn loaded cabs with scoops. Can subs with scoops even be time aligned??
One aspect of sub alignment I have had the most trouble with has been getting a good impulse response out of a subwoofer. For whatever reason, subs never show any kind of usable impulse response in OSM. the delay locater also has some trouble. Why is that?
An impulse response won't give you a sharp "peak" for the program to latch on to with LF energy. It needs HF energy to do that.
You can sometimes turn the crossover fully off to find the delay point, it'll make your sub act, momentarily, like a really shitty full range speaker, and then you can capture it that way, then measure with the crossover on. Easy on passive subs because they just do what they're told. Don't run them loud while doing this.
This is a similar approach to how Nathan lively shows it
Hey Michael I purchased your 177.00 half price deal for last Friday August 11.
A few things that wasn’t clear to me.
1. On the mains K12.2 you placed a BW LPF 4 on the top end to get rid of that zippynees you call it which was definitely interesting vs using a high shelve. Totally cool.
BW HPF 2.
But you didn't deploy any filters on the subs???
Why a BW HPF 2 rather than something steeper?
How do you even determine that type and order filters?
This bar has K12.2 for the mains.
2 500w jbl prx 518s for subs and using a driverack for the xover.
WHAT TYPE FILTERS AND SLOPE WOULD YOU DEPLOY?
I have a HPF 48 Slope and a LPF 36 slope on the subs, both BW.
On the mains, L&R HPF 36 slope and I will be changing the top end to a BW LPF 4 like you used to clean up the zippyness.
I'm also xover at 80hz. You seem to use 100hz a lot. NEED YOUR HELP ON ALL THIS.
Just guide me what filters we should be using?? I'm just a single doner who helps a bar keeping it rocking hard.
It took me more than 5 years but I finally got my way stacking the subs on house right next to a wall underneath the house right mains. 2 subs now sounds like 6 subs.
But where do I shoot for even tonality since the subs are not symmetrical placed on one side?
No more power alley power valley that's for sure. Nice even low end everywhere in the room. Thanks to Nathan Lively and Subwoofer Saturday. Had a Def Tones and Tool Tribute band last weekend. That kick was hitting fairly hard at a good 45hz.
Hope you also clear up the front fill and why you had to invert the mains to align the subs?
THANKS MUCH FOR YOUR LIVE CLASS AND LIFETIME VIDEO.
It's going to take lots of practice from foh mixer to systems turning.
Some of this stuff is hard especially xover, filters, alignment..
Peace ✌️ ☮️ 🕊 🏳️
Glad you liked the workshop!
No filters on the subs since they already have built in high pass and low pass filters from the manufacturer optimizing their bandwidth and performance.
As far as the specific filters you need for your setup, it just depends on how much overlap you want between the mains and subs and their relative phase responses. I'd look at JBL's documentation to see if they have recommended crossover frequencies as well as filter slopes.
You're right, with your sub setup you gained total SPL output by coupling them with the wall, but sacrificed even tonality because they're off to one side. No such thing as free lunch : ) If eliminating power alleys and getting more SPL is more important than the LF feeling a bit tilted off to one side, keep it.
I inverted the mains because that's what made the phase traces of the mains line up best with the KS118.
@MichaelCurtisAudio Amazing it doesn't sound so uneven at all.
I'm thinking when I attempt to retune I might need to go with unlink left & right so I have separate eq vs linked.
So what's the top secret magic filters and slopes in those K118's?
What xover frequency do you favor, 80hz or 100hz? I've always used 80hz.
I have 4 horn loaded sub cabs Stanco Audio was built back in the 80's. Loaded with jbl 2241h. They just don't really hit really low but they are scary. Can they actually be time aligned to mains knowing there is a delay and and hit twice due to the scoops?
Yes the workshop wad fabulous 👌
what does the sum look like without the delay?
It depends on how much they're offset, but you'll see slow and steady reduction in level within the overlap region.
is it okay if we set delay more than 5ms in our sub ?
If that's what is needed to align it with your mains, sure thing.
I can't download measurement in tracebook, help
Where can I download the Michael Lawrence target curve for open sound meter?
It's in my audio toolkit.
@MichaelCurtisAudio I believe I have it. I'll have to look again. Looks like a nice target just what most ears deserve.
sound meter software not installed. some installion file missing this software. so how i get orginal software for windows
Which software? Smaart or OSM?
OSM@@MichaelCurtisAudio
I can't find where to download the txt files on the website
needed to confirm my account through email
Out of nowhere you start talking about smaart but we're in OSM. That was a distraction.
Can you use an external driverack with active speakers instead of using the speakers internal built-in xover?
Every time I try this, it always says an error with summing them "Source size not the same"
It requires both measurement to be taken at the same sample rate and at the same FFT size.
Having a challenge with loading the .osm file. keeps closing the osm software anytime I launch it
Sometimes it works better if you launch OSM first, then to go to open --> then the file. Is it crashing when you do that?
@@MichaelCurtisAudio Yes it does...
Totally confusing! You're now saying use the mains as reference but use no delay finder, 0.00ms. Recently you mentioned use mains as reference and use delay finder on mains only.
You're also talking about smaart here but you have OSM opened. 😢
First you get a trace of your main as a reference, so you use a delay finder. Then you switch to your subs, but you don’t use a delay finder anymore, you just tweak delay time to match the phase curves.