The Lessons Of El Ridiculoso

Loudspeaker experiments are very educational.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

El Ridiculoso is an idea that’s been bumping around in my head – conceptualized in various morphologies – for years. With the help of the extravagantly cool Mario Caliguiri, who does custom woodworking out here in the high desert, the idea is now incarnated.

Inwoodnated.

Inwoodnated is a real word, because I made it up. All words are made up.

Anyway…

El Ridiculoso is a quad-amped monstrosity meant to go “pretty loud” (but not insanely loud) with 2300 watts of peak input creating about 131 dB of peak, 1 meter SPL. It is very definitely NOT meant to play down low. The conveniently-sized, sealed box for the 15″ driver starts rolling off somewhere around 75 Hz, and really, El Ridiculoso is supposed to be used with subwoofers carrying everything up to 100 Hz anyway. (Sealed boxes are easier to build, and generally pretty forgiving. You can “fudge” the internal volume a bit and still have the whole driver-and-box system work pretty well.)

A few days ago, I got to hook amplifiers up to the boxes and hear them make noise. I found the experience to be rather educational in a few areas.

If You Tune It By Ear You Will Probably Get It Wrong

I set up an X32 mixing console to act as a four-way crossover: You downmix two channels to the main bus, and then send the main bus to matrices 1-4. (The matrices have crossover filters available to them if you have the right firmware upgrade in place.) Because I wouldn’t be working with subwoofers for the test run, I started off by putting the 15’s high-pass at 75 Hz, with the low-pass at 400 Hz. The 12 handled 400 – 1600, the big horn did 1600 – 6400, and the smaller horn took everything above that.

And, of course, I started out by playing music and pushing the different bandpass levels around.

I ended up with an overall sound that was reasonably pleasing, but somewhat tubby (or resonant) at certain bass frequencies. I wondered if the 15’s box was booming for some reason – maybe it was acting like a drum?

In any case, I decided it was time to do some measuring for a real, honest-to-goodness magnitude line-up of the boxes. As I started running sweeps and making adjustments, one thing became VERY clear: Tuning the system by ear had sent me way off course. In some cases, 10+ dB off course. (!)

A Basic Bandpass Magnitude Alignment Fixes A Lot

When you’ve missed the mark as far as I had, information that should blend nicely with other information…doesn’t. You get things like overpowering bass notes, because the crucial midrange just isn’t there to balance it all out. I was actually pretty stunned at just how much better the stack sounded with all the boxes in basically the right place, volume-wise. The music I was playing suddenly started to have the tonal characteristics I’d grown used to from listening at home.

This was without any corrective EQ, which is what I worked on next.

Going through and getting a fine-detail equalization solution certainly changed things, but the difference was not nearly as pronounced as what had happened before. This surprised me as well. I had expected that applying the “make-em-really-flat” solution would result in a massive change in clarity, but really, we were most of the way there already.

Large Horns Make Large Noise

I discovered rather quickly that sitting with my head right up against the 2″ driver-exit horn was unpleasant. The amount of noise that thing can make is impressive. The matrix feed to that bandpass ended up being 12 dB down from everything else, and I still preferred being across the room. I’ve known for years – at an academic level – that 2″ exit compression drivers are used when you need to tear faces off, but this was the first time that I even got a whiff of what they’re really capable of.

Awesome But Impractical

Playing with El Ridiculoso is a great treat, but I can’t imagine getting three more built for regular gigs. For a start, they’re relatively complicated to set up, because all the bandpasses are in separate enclosures…and there are four bandpasses per speaker system. Big-boy loudspeakers might have three bandpasses, but they package them all into a single cabinet. Plus, you usually get one Speakon connector which you can use to mate all your power channels to all your drivers in one click. El Ridiculoso needs four separate connections to work.

Add to that the need for subwoofers in many cases, and now you’ve got a five-way system. Then you have to add all the amplifiers necessary, and all the crossovers/ system management, which results in a pretty hefty drive rack or two. Then you have to add all the speaker cable. You end up spending a lot of money, and a lot of weight, just to make the things work.

And, the only way to get them up in the air is scaffolding, or stacking them on a big pile of subs.

In the end, a compact, ultra-engineered box from a major manufacturer really has the advantage. El Ridiculoso sure does have a lot of “cool factor” as an exotic idea, but a good, solid, self-powered biamp unit will go just about as loud and require far less care and feeding to be day-to-day useful.

This doesn’t mean I’m sad about the experiment. I knew from the beginning that I wasn’t going to design a better mousetrap than every speaker manufacturer on the planet. What I wanted is what I got: A different implementation that I could use to get more hands-on understanding of how these things work.


The Pro-Audio Guide For People Who Know Nothing About Pro-Audio, Part 2

The series continues with a discussion on cable.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

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From the article:

“The simplest and most robust connection possible is a single cable carrying analog electrical signals. Analog cabling is subject to many problems, of course, including noise induced by electromagnetic interference. However, its simplicity reduces the number of ways that an outright failure can occur, and the connection tends to degrade “gracefully.””


Read the whole thing for free by visiting Schwilly Family Musicians.


Not Everybody, Not All The Time

Care about everything you can, then be okay with everything else.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

A letter to myself and others:

You can’t please everybody all the time.

You can try, of course, and you should. Show production is a service industry that’s always been a service industry. It always will be. Getting the maximum number of people to be delighted with the show IS your job.

But 100% satisfaction for everybody is very difficult to get to. Somebody will always manage to sit in the seat where the PA coverage isn’t quite right. Somebody will inevitably wonder why you didn’t make Band A sound like Band B, even though Band A has made arrangement choices such that they CAN’T sound like Band B. You will never have enough subwoofer for “that one guy.” Someone is going to lecture you on how their preferred snare-drum sound is THE key to a rock mix.

There is nothing so good that someone, somewhere will not hate it. So says Pohl’s law, if the Intertubes are to be believed.

You’re going to have to make choices about what to prioritize. That’s part of sitting in any of the chairs involved in show control. By necessity, you will be making choices (many of them, at high speed) that have real – though usually ephemeral and ultimately benign – effects on the lives of a sizable number of people. You must therefore cultivate an assuredness, an appropriate level of confidence that you are doing the right thing. Beyond having a strong appreciation of personal and collective aesthetics, this confidence will be greatly bolstered by understanding the physics involved in this job. If you know what’s possible and what’s not, you will be less rattled when someone accuses you of not having done the right thing…when their right thing wasn’t a feasible thing anyway.

It’s right to take all concerns seriously, but not all concerns can be treated with the same level of seriousness. Start by making as many musicians as happy as you can. That’s your baseline. If you get the baseline done, and somebody else isn’t happy, consider if that person is writing the checks for the event. If so, working out a compromise will probably be in order. An extreme case might require that you just do as you’re told. After you get that squared away, you can start being concerned about other considerations brought to your attention. If you can take care of them without changing the happiness level of the check-writer or the players, go ahead.

If not, be polite, but don’t worry too much. Even big-dollar gigs can’t deploy enough gear to fix everything.

Do your best, have fun, and try to get as many other people to have at least as much fun as you’re having. Do maintain care for the outliers, but don’t agonize. It won’t get you anything, anyway.


It’s Not About The Gear – It’s About Receipts

Sure, it’s a cool toy – but can you make money on it?

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

If you want to hear great wisdom about the business of sound and music, you should seek out Tim McCulloch over at Pro Sound Web. Just recently he was advising another audio human to “get very real” with a band about demanding a certain console for a tour. Having gotten the strong whiff that the choice of mixing desk was basically one of vanity, Mr. McCulloch dropped the proverbial load of bricks: The gear you take on tour is – and should be categorized as – an expense. The merch and tickets you can sell are profit. (So, decide if you want to make a profit and then act accordingly.)

Of course, the application of this to band tour-o-nomics is self explanatory. With just a bit of imagination, though, you can see how this applies everywhere – especially to audio craftspersons who own equipment.

The gear you own is an expense. It’s always an expense. It’s an expense when you make a full or partial payment for purchase. It’s a debit if you’re making leasing payments. It’s a negative ledger entry every second of every day, because its value depreciates forever in an asymptotic slide towards $0. It’s also a constant drain because you are always paying to store, maintain, and replace it (even if you don’t see a bill directly).

The above is a big reason behind why Tim McCulloch will also tell you that “Excess capacity is infinitely expensive.”

Anyway.

Equipment does not represent profit. It’s a tool that can be used to generate profit, but if you want to imagine the audio business as an airplane, gear is a constant contributor to weight and drag. What you need to keep going is lift and propulsion – profit, that is. Receipts. Money coming in. As such, every purchase and upgrade plan has to answer one question: “How will this increase my receipts?”

The harsh truth is that, past a certain point, just being able to get louder probably won’t increase your receipts.

Past a certain point, being able to rattle peoples’ rib cages with bass probably won’t increase your receipts.

Past a certain point, “super-trick,” spendy mics probably won’t increase your receipts.

A nifty new console probably won’t increase your receipts (not by itself).

What many of us (including myself) have a longstanding struggle with understanding is that what we THINK is cool is not necessarily what gets us phone calls. Meeting the demands of the market is what gets the phone calls. For those of us with maverick-esque tendencies (like Yours “Anti Establishment Is Where It’s At” Truly), we have to take care. We have to balance our curiosity and experimental bent with still being functional where it counts.

We CAN be bold. In fact, I think we MUST be bold. We ought to dare to be different, but we can’t be reckless or vain. If we’re in a situation where our clientele encourages our unorthodoxy, we can let ‘er rip! If not, then we have to accept that going down some particular road might just be for our own enjoyment, and that we can’t bet our entire future on it.

By way of example, I can speak of my own career. I’m currently looking at what the next phase might be like. I have a whole host of notions about what upgrade and expansion paths that might entail. I’ve also gotten on the call list of a local audio provider that I really, really enjoy working with – and the provider in question is far, FAR better than I am at scaring up work. With that being the case, some of my pet-project ideas are going to need a hard look. In devising my upgrade path, it’s far smarter for me to talk to the other provider and find out what would dovetail nicely with their future roadmap, rather than to just do whatever I think might be interesting. Fitting in with them means a chance at more receipts. More receipts means I can do more of what I love. Doing more of what I love means that I might just have enough excess capital to do some weird experiments here and there.

I don’t say any of this to dampen anyone’s enthusiasm. I say this so that we can all be clear about our choices. There are times when we might declare, “Damn the torpedoes, full speed ahead!” It’s just that we sometimes say that without realizing that we’ve said it, in terms of business decisions. If we’re going to buy tools to make money with, it’s a very good idea to figure out what tools will actually serve to make money.


Mentalism

“Subjective” problems are still problems that have to be taken seriously.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

I’m not a doctor, nor do I play one on TV. However, I have known doctors – really good ones – and though they’ve never said this explicitly, I think they would be of the opinion that a problem in the mind IS a real problem. That is, if a patient is experiencing distress that is caused by the brain, then they are really experiencing distress. The key isn’t to tell the complainant that what’s happening to them is fake, because it clearly is not fake. Rather, if the problem truly is in the mind then the solution must be applied at the problem.

Which is in the mind.

This might not seem like something to do with audio, but you have heard that part of an audio-human’s job is psychology, right? It’s said jokingly, but it shouldn’t be. It’s true. Musical craftspersons of all types have been known to run into problems at a show that really do exist…just inside their own head.

Something just doesn’t seem right. A guitar tone feels “off.” The vocals aren’t sparking with the same magic. I liked that reverb yesterday, and now it’s awful. This DI box doesn’t work right with my instrument.

Especially for us science-oriented types, our response to this takes work. Because we’ve spent so long trying to cut through the vast piles of horse-doodie that pervade the industry, we get dismissive. “Nothing’s different, man. It’s just your imagination. Ignore it.” But they CAN’T ignore it. They’re experiencing it, or they’ve convinced themselves that they are, and that is plenty good enough for them.

This is why an understanding that audio is a service business is so important. This is why an attitude of cooperation ought to be cultivated. Some perceptual issues can’t be worked out by applying a tech-based change, but they can at least be alleviated. The salve that can be applied is a willingness to treat the mental malady as a true conundrum requiring attention. They want you to turn the knobs? Turn ’em! They want you to swap the cables? Swap ’em! They want you to drive the system into feedback (with an audience present) so that they can go after the ringing frequencies with their own EQ, and then drop the gain back to where you had it? Go for it! (This has actually happened to me, by the way.)

In the moment, taking a desired action matters greatly – even if that action is not likely to physically affect much of anything – because what you’re really applying the fix to is a person and not the PA. After all the dust has settled, THEN you can talk about whether or not the distress was objective or subjective. Rationality is a part of handling whatever bugbear there was, but rationality only works when people are calm. The important thing “in the now” is being on the same team…and proving it.

Refrain from lecturing in a crisis; The person experiencing the crisis can’t process what you’re saying.

I think I’ve proven many times on this site that I value an analytical approach. I put very little stock in “audio theater,” which is using techniques and buying gear that make you THINK a problem is getting fixed, rather than actually fixing something. I don’t advocate doing something damaging or insane just to make somebody else feel better; Sound people need to know what’s a flat-out bad idea. Diplomacy, though, is essential. When the show must go on, there’s little use in winning a technical argument. What’s needed is to get everybody to a place where they’re as happy as is physically and mentally possible.


Console Questions

A few simple queries can get you going on just about any console.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

Back when I was in school, we were introduced to “The Four Console Questions.” The idea behind the questions was that, if you walked up to a strange mixer, you could get answers to the questions and be able to get work done. Mixing desks come in many varieties, but there aren’t very many truly different ways to build them that make sense. In any case, all the basic concepts have to essentially stay the same. If a console can’t take some number “a” of audio inputs, and route those inputs to some number “o” of outputs, you don’t have a mixing console anyway.

With the growing commonality of digital mix systems, I feel that the essential “console questions” need some expansion and tweaking. As such, here’s my take on the material that was presented to me over a decade and a half (GEEZE!) ago.

1. Do I Know What I Want To Do?

You might say that this isn’t a console question at all, but in truth, it’s THE most important one. If you don’t know what you want to do with the console, then knowing a bunch of information about the console’s operation won’t help you one iota. The unfortunate reality is that many people try to engage in this whole exercise backwards; They don’t know what they want to accomplish, but they figure that learning the mixer’s whys and wherefores will help them figure it out.

Certainly, learning about a new feature that you haven’t had access to previously can lead you to new techniques. However, at a bedrock level, you have to have some preconceived notion of what you want to accomplish with the tool. Do you want to get a vocal into the FOH PA? Do you want to get three electric guitars, a kazoo, and a capybara playing Tibetan singing-bowls into 12 different monitor mixes?

You have to know your application.

2. How Do I Correctly Clock The Console?

For an analog console, the answer to this is always: “No clock is required.”

For a digital rig, though, it’s very important. I just recently befuddled myself for an agonizing minute with why a digital console wasn’t showing any input. Whoops! It was because I had set it to receive external clock from a master console a few weeks before, and hadn’t returned it to internal clocking now that it was on its own.

You need to know how to indicate to the console which clock source and sample rate is appropriate for the current situation.

3. How Do I Choose What Inputs Are Available To The Channels?

This is particularly important with consoles that support both on-board input and remote stageboxes. You will very likely have to pick and choose which of those options is available to an individual channel or group of channels. What you need to discover is how those selections are accomplished.

4. How Do I Connect A Particular Input To A Particular Channel?

You might think this was covered in the previous question, but it wasn’t. Your global input options aren’t the end of the story. Many consoles will let you do per-channel “soft-patching,” which is the connection of a certain available signal to a certain channel without having to change a physical connection. Whether on a remote stagebox or directly at the desk, input 1 may NOT necessarily be appearing on channel 1. You have to find out how those connections are chosen.

5. How Do I Insert Channel Processing?

In some situations, this means a physical insert connection that may be automatically enabled…or not. In other cases, this means the enabling and disabling of per-channel dynamics and/ or EQ, and maybe even other DSP processing available onboard in some way. You will need to know how that takes place, and with all the possible variations that might have to do with your particular application, it is CRITICAL that you know what you want to do.

6. How Do I Route A Channel To An Auxiliary, Mix Bus, Or The Main Bus?

Sometimes, this is dead-simple and “locked in.” You might have four auxiliaries and four submix buses implemented in hardware, such that they can only be auxiliary or mix buses, with the same knobs always pushing the same aux and a routing matrix with pan-based bus selection. On the other hand, you might have a pool of buses that can behave in various ways depending on global configuration, per-channel configuration, or both.

So, you’ll need to figure out what you’ve got, and how to connect a given channel to a given bus so that you get the results you want.

7. How Do I Insert Bus Processing?

This might be just like question 5, or wildly different. You will need to sort out which reality is currently in play.

8. How Do I Connect A Given Signal To A Physical Output?

Just because you have a signal running to a bus, there’s no guarantee that the bus is actually going to transfer signal to any other piece of equipment. Especially in the digital world, there may be another layer of patching to assign signals to either digital or analog outputs. Bus 1 might be on output 7, because six matrices might be connected to the first six outputs. Maybe output 16 is a pre-fader direct out from channel 4.

You’ll have to figure out where all that gets specified.


Obviously, there’s more to being a whiz at any particular console than eight basic questions. However, if you can get a given signal into the desk, through some processing, combined with other signals you want to combine, and then off to the next destination, you can at least make some real noise in the room.


How To Tell If The Band Is Awesome

It involves you doing less.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

I was sitting there at the first IAMA LCS concert of the 2017-2018 season, just minding my own business. (Which is to say that I was minding both the audience’s and the band’s business, at least in terms of sound.)

Suddenly, it hit me like a ton of bricks. Tony Holiday and The Velvetones were fully in the groove and having a great night. Now, The Velvetones have always been a very good band. There have been many incarnations and cast members. Eeach iteration has marked some improvement over an older version, but there was never a point where Tony failed to bring a great lineup to the table. This particular ensemble on this particular night, though, had reached a remarkable apex. They had entered a zone that not many bands (even good ones) gain an ingress to.

They had reached the point where they, by the very nature of their rehearsal and experience, required no intervention from me in order to function perfectly as a band. I could have locked out my remote-control laptop, left the building, had a late dinner at a restaurant, and come back just in time for load-out, and the show would have been pretty much fine. I didn’t do that, of course – I needed to make some tweaks because the mix was being built entirely on the fly, and not all of my assumptions were complete or correct.

But that was the key: The only reason I needed to make adjustments was because I needed to change what I was doing to the band, not because a modification was required for what the band was doing to us in the seats.

The mix for a really good group should display characteristics that (I’ve heard) are what can be expected from a well-behaved airplane. The whole thing should have a tendency to settle into a stable, controlled trajectory, where you don’t have to sledgehammer or wrestle the ship into obeying you. This was one of those times, and it was glorious. The band was on point, and I didn’t screw it up. Such things are commonly referred to as “wins,” I believe, and are worth pursuing due to their sheer enjoy-ability alone.


The Pro-Audio Guide For People Who Know Nothing About Pro-Audio, Part 1

A series I’m starting on Schwilly Family Musicians.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

From the article:

“The fundamental key to all audio production is that we MUST have sound information in the form of electricity. Certain instruments, like synthesizers and sample players don’t produce any actual sound at all; They go straight to producing electricity.

For actual sound, though, we have to perform a conversion, or “transduction.” Transduction, especially input transduction, is THE most important part of audio production. If the conversion from sound to electricity is poor, nothing happening down the line will be able to fully compensate.”


Read the whole thing here, for free!


Is The Crossover Leaky?

A lot of low-end can still get into your mains.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

Every so often, I get to chew on a question that a reader asks me directly. I kinda wish that would happen more often (hint, hint, hint…). Anyway, I was sent a message on The Small Venue Survivalist’s Facebook page, asking if I could render an opinion on why a bass guitar seemed to have a surprising amount of LF information in the main speakers. The mains were being used alongside a subwoofer, with the sub providing a crossover filter at 100 Hz. What could the issue be?

There are a few explanations that would seem reasonable, if one discounts “catastrophic” issues like the crossover filter simply failing to operate as advertised.

1. Crossover filters, especially those implemented in active electronics, have a tendency towards a relatively steep slope. Even so, they usually aren’t brick-wall implementations. Everything below the cutoff doesn’t simply disappear – rather, it’s attenuated at a certain rate. With a filter set to roll off everything “below 100 Hz,” the mid-highs are still being asked to do a fair bit of work at the crossover frequency. The general vicinity of 100 Hz is actually quite bassy (depending on who you ask, of course), so the mains might be perceived as doing more than they should when everything is quite normal.

2. If a sizeable pile of low-frequency energy has been dialed into the bass-guitar channel, or the bass-guitar’s pre-console tone, that big hill-o-bass won’t be tamped down by the crossover. It will be split up proportionately, but following on from the first point, the mid-highs will still be tasked with reproducing their allotted piece of that big LF mound. Consequently, a surprising amount of energy may be present in the tops.

3. I have a suspicion that plenty of modern, two-way boxes receive some degree of “hyping” of their low-end at the factory. This makes them sound more impressive, and the manufacturer can get away with it because of safety limiters placed post-EQ. (The limiter prevents the low-frequency amplifier from supplying more voltage than the woofer can handle, and there may even be a level-dependent high-pass filter in play.) A low-frequency boost that occurs after the crossover reduces the crossover’s apparent effectiveness. Sure, the signal leaving the crossover might be down 12 dB at 75 Hz, but a +6 dB shelving filter put in place by the manufacturer at 100 Hz “undoes” that filtering to only lose 6 dB. Once again, a potential situation develops where the mid-highs are being asked to reproduce more “boom” than you expected.

It is entirely possible that an apparent problem isn’t covered by the three possibilities above, but they should catch quite a few scenarios where everything is hooked up properly and configured correctly.


EQ Propagation

The question of where to EQ is, of course, tied inextricably to what to EQ.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

On occasion, I get the opportunity to guest-lecture to live-sound students. When things go the way I want them to, the students get a chance to experience the dialing up of monitor world (or part of it). One of the inevitable and important questions that arises is, “Why did you reach for the channel EQ when you were solving that one problem, but then use the EQ across the bus for this other problem?”

I’ve been able to give good answers to those questions, but I’ve also wanted to offer better explanations. I think I’ve finally hit upon an elegant way to describe my decision making process in regards to which EQ I use to solve different problems. It turns out that everything comes down to the primary “propagation direction” that I want for a given EQ change:

Effectively speaking, equalization on an input propagates downstream to all outputs. Equalization on an output effectively propagates upstream to all inputs.


What I’ve just said is, admittedly, rather abstract. That being so, let’s take a look at it concretely.

Let’s say we’re in the process of dialing up monitor world. It’s one of those all-too-rare occasions where we get the chance to measure the output of our wedges and apply an appropriate tuning. That equalization is applied across the appropriate bus. What we’re trying to do is equalize the box itself, so we can get acoustical output that follows a “reference curve.” (I advocate for a flat reference curve, myself.)

It might seem counter-intuitive, but if we’re going to tune the wedge electronically, what we actually have to do is transform all of the INPUTS to the box. Changing the loudspeaker itself to get our preferred reference curve would be ideal, but also very difficult. So, we use an EQ across a system output to change all the signals traveling to the wedge, counteracting the filtering that the drivers and enclosure impose on whatever makes it to them. If the monitor is making everything too crisp (for example), the “output” EQ lets us effectively dial high-frequency information out of every input traveling to the wedge.

Now, we put the signal from a microphone into one of our wedges. It starts off sounding generally good, although the channel in question is a vocal and we can tell there’s too much energy in the deep, low-frequency area. To fix the problem, we apply equalization to the microphone’s channel – the input. We want the exact change we’ve made to apply to every monitor that the channel might be sent to, and EQ across an input effectively transforms all the outputs that signal might arrive at.

There’s certainly nothing to stop us from going to each output EQ and pulling down the LF, but:

1) If we have a lot of mixes to work with, that’s pretty tedious, even with copy and paste, and…

2) We’ve now pushed away from our desired reference curve for the wedges, potentially robbing desired low-end information from inputs that would benefit from it. A ton of bottom isn’t necessary for vocals on deck, but what if somebody wants bass guitar? Or kick?

It makes much more sense to make the change at the channel if we can.

This also applies to the mud and midrange feedback weirdness that tends to pile up as one channel gets routed to multiple monitors. The problems aren’t necessarily the result of individual wedges being tuned badly. Rather, they are the result of multiple tunings interacting in a way that’s “wrong” for one particular mic at one particular location. What we need, then, is to EQ our input. The change then propagates to all the outputs, creating an overall solution with relative ease (and, again, we haven’t carved up each individual monitor’s curve into something that sounds weird in the process).

The same idea applies to FOH. If the whole mix seems “out of whack,” then a change to the main EQ effectively tweaks all the inputs to fix the offending frequency range.

So, when it’s time to grab an EQ, think about which way you want your changes to flow. Changes to inputs flow to all the connected outputs. Changes to outputs flow to all connected inputs.