Robert Scovill
EAW's Live Sound Market Manager
As topics go, few spark more tribalism than discussions around the development and use of active vs. passive PA enclosures. But in an effort to not “bury the lead” here, I’m going to state right up front that regardless of your loyalties and dedication to either active or passive platforms, in my mind, one thing is indisputable; if the trend toward higher density, full bandwidth line source, and arrays continue, and you look far enough out on the horizon, all of the offerings are active enclosures. Of course, as I hope you’ve discovered in my previous blogs and webinars, the path to full-bandwidth line sources and line arrays is born of smaller and smaller high-frequency components in conjunction with more and more density of discrete transducers, amplifiers, and DSP per enclosure. At some point, this alone breaks the passive concept down to complete impracticality. And that is the lens I will be viewing through for this blog.
For large-format concert sound and sound reinforcement, passive designs by their nature have been around since day one. The concept of internally amplified (not necessarily processed) enclosures likely experienced its genesis with the trapezoidal Meyer MSL4 in 1995. For the time, this was a pretty aggressive move for Meyer, especially from the standpoint of enclosure and array weight, as anyone who has used MSL4 would attest, given that it was a stout 205lbs. The internal amplification was a custom-built class AB/H, which added significant weight to the enclosure, making it challenging to deploy. This may have actually set the tone for some initial negativity in the minds of users toward active designs going forward. In that form factor, it was clear that if active enclosures were to become a reality for the future of large-scale concert sound, a new amplifier concept would need to emerge. Hence, the initial move to active was tepid at best, despite MSL4 being highly regarded. For context, the JBL 4889ADP-DA, a 3-way active line array enclosure with an internal 3-channel amplifier, DSP, and 9 transducers,including a 15” woofer, weighed in at 205lbs, exactly the same weight as the “OG” MSL4.
In the heyday of horizontal arrays, the thought of amplifying each transducer discretely, heck, even each cabinet independently, seemed a very rich pipe dream, but in practice it was wildly overenthusiastic, if not downright impractical. Array weight aside, the sheer expense of doing so with regard to overall system infrastructure costs, and in turn client pricing, coupled with transportation expenses, would have been excessive by anyone’s measure at the time.
But then, along came line arrays. It doesn’t require the luxury of hindsight to recognize that the industry turned on a dime, and seemingly overnight, the entire industry turned its focus to developing line arrays. The move to concert sound-capable line array systems is a pure study in cause, effect, and well-executed compromise. While the early versions of concert-level line arrays did yeoman’s work in meeting the line array criteria for a portion of the bandwidth, line source designs hit their first obstacle in creating a full-bandwidth single acoustic source in the high-frequency passband. What resulted was a hybrid array of line source upto a given frequency, crossed over to a point-and-shoot horn approach for the high-frequency range elements. The “cause” was demand for improved acoustic phase for concert arrays, and the “effect” was the development of the isophasic wave guide, where a single enclosure could present a single acoustic source. But using multiple enclosures resulted in multiple acoustic centers above a given driver spacing, so the promised land was in sight, but not in hand just yet.
This, of course, led to other cause-and-effect models. With the level of accuracy in directivity control that line arrays now offer, the need for accurate prediction software to establish accurate start and stop coverage points for a seating geometry and the subsequent enclosure angles required for the point-and-shoot elements was essential.
Next came the introduction of the option for a self-powered line array enclosure with networked audio transport and processing. JBL introduced the Vertec line withthe option for enclosure-mounted amplifier and processing modules using AES3 audio and a proprietary audio transport and DSP control of internal DBX DriveRack processing via the protocol (HiQ net). The cause, of course, was greater control of the tonal response within the predicted coverage geometry, and the effect was more granular and discrete transducer amplification and processing. This arrived with the model I mentioned above, the JBL VertecADP DA.
But here’s the rub: always lurking in the shadows was the initial challenge of the high-frequency section’s inability to meet the spacing criteria demanded for a true line source. It, in and of itself, tended to neutralize the use of discretely processed transducers in these arrays because the extremely narrow vertical directivity of the new horns stole away the necessary overlap for meaningful directivity manipulation for the pass band.
And here’s where the practicality of the initial line array designs began to sort of “cement” the point-and-shoot model into place. I vividly remember when the first large-scale line array was coming online in the early 90s. The response from the sound reinforcement community was “line source? Why in the world would we want a line source in concert sound?” It’s my belief that this centered around the high-frequency elements because if you concede that by using a small enough driver, spaced properly to meet line source criteria via the stacking of the drivers, what you’ve physically initiated is an incredibly high-Q response from the enclosure, especially so for the high-frequency pass band. This, in and of itself, would be a horrible choice for concert sound with no way to control this narrow directivity. So, I certainly understand the concern initially expressed, meaning: if you did meet the criteria for size spacing, what would you do then?? If you were to make it to that point in design, you must, in turn, concede that to use it, you need to unpack that collapse into a meaningful, intentional vertical coverage. To do so,you’ll need a LOT of discrete amplification and processing to create that intentional coverage. This is referred to today as “density”. Transducer density, coupled with amplifier and DSP density dedicated to each driver, gives you the ability to fully create a vertical polar. However, this would be highly impractical to do manually on a show day or even for a given install. The concept demanded that you would need computer assistance to accomplish it. You would not be able to “spreadsheet” and “enter data” manually to form a polar shape in any kind of practical time frame. And if you want to change something slightly? Yeah, see ya’ tomorrow.
The multi-transducer, amplifier, and DSP model, in and of itself, demands an active design for your enclosures. For example, in a basic 15” enclosure, to create ahigh-frequency line source above 12kHz is going to require at least 15” of 1” high-frequency spacing to achieve it. You can do the math pretty quickly by examining EAW’s Anya enclosure and realizing that there are 22 components on board requiring 22 amplifier channels coupled with 22 DSP channels. All transducers create an ever-expanding stack of drivers addressing the lowest to highest frequency range offered by the system. It would, in turn, also require networked control of the DSP in that there was no way you were going to deploy this passively with 22-pair speaker cable and 22 drive lines per enclosure. Computer and software design aside, this was simply a bridge too far for early line array designs, given the technology of the driver, amplifier, DSP, and audio delivery options of the times.
So, the concert industry got “comfortable” with the passive topology for the years to come. Even when Vertec came online, it was really primarily about internal amplification and group equalization rather than array pattern and directivity control. The existing point-and-shoot aspect of the high–frequency neutralized the need for highly discrete control, since meaningful impact on directivity would be difficult to achieve to any meaningful degree.
But then, in 2012, EAW made a bold and strategic decision to go straight to the future with line-source and line-array systems. Doing so resulted in the first true line-source module and, in turn, the first true full-range, fully adaptive line-array that was concert sound capable. This also served as an initiation of sorts for the dawn of fully active enclosures for line arrays in concert sound. Lead engineer on the project, Geoff McKinnon, recently related to me, “It was like we jumped into a time machine and time-traveled about 20 years into the future.” When they returned to the year 2012 and debuted ADAPTive to the public, I can hear them paraphrasing Doc Brown — “Speaker cable? Where we’re going, we won’t need speaker cable.”
I’m on record as saying it, and I continue to stand behind my words. “If you go far enough out on the horizon, and if the commitment to creating full bandwidth line sources is fully adopted by the industry, everyone will be deploying active enclosures. It’s not a matter of if, it’s a matter of when.” EAW competitors are already ramping up the density in their designs. But EAW is assured of a long-standing head start on the development of this enclosure topology, and, maybe more importantly, a decade or more ahead on the development of the required prediction and control software.
So, with all this history and the future in mind, I thought it might be useful to examine a few of the generally accepted narratives about active vs. passive system designs and maybe even do a little “myth busting”. Over my 15 years with ADAPTive, and now while working directly on next-generation ADAPTive on behalf of EAW, I have heard an awful lot of misperceptions and things that are simply figments of people’s imaginations. So, I’m committed to cleaning that all up before we get to the actual next-gen products. These sections are all based on things I’ve heard someone proclaim firsthand.
"I don’t wanna be forced to use “Networked Audio” with my PA system. Aren’t all Active boxes totally reliant on these audio transport protocols?"
It’s important to compartmentalize this line of thinking in order to frame it correctly. If an active enclosure offers onboard amplification only, it then likely offers an analog or an AES input choice, allowing you to make a physical choice. But this concedes that the system will be processed from a location away from the enclosure or the array. That processing would need to be delivered via the given cable format and then distributed to all of the amplifier channels. It also concedes that there’ll not be very much “discreteness” to the processing in that doing so would require a separate delivery line for every channel of processing in the user’s choice of how many amplifiers would carry common versus unique processed signals. Purely from a cabling perspective, this would get unruly very quickly. This, of course, is the allure of networked audio transport and control: being able to deliver massive amounts of audio down a single small-format cable and, in addition, being able to control and process those individual signals discretely.
In ADAPTive systems, you have the best of both worlds. With fully redundant Dante audio transport and control, you can remain fully in the digital domain, or you can use a simple analog loop-through while retaining discrete DSP control of the system, identical to when using Dante for the audio transport. That is one of ADAPTive’s well-hidden gems: you can have an analog audio path while retaining complete control of all the onboard DSP while providing unrivaled vertical coverage.
“Class D amplifiers used in active designs are still too new and untested under fire. Also, they don’t sound as good as rack-mounted amplifiers."
Okay, let’s start with the easy part of this. I’m surprised how often I hear this sort of rhetoric in casual conversation in our industry. It’s often framed as the idea that today’s rack–mounted amplifiers are somehow superior to amplifiers deployed as an element of an active speaker enclosure designs. From the crowd I regularly hear from, it suggests a belief that rack–mounted amps used with passive systems are in some way superior to their active–enclosure counterparts. The simple response is that they’re not. All the “big boy” line arrays today are deploying Class D amplification. It just happens to be in a rack–mounted form factor. These are not Class–AB designs, or even a variant. The truth is Class D amplification has been in service for many years now and has proven itself very capable and up to the task at hand.
“I don’t want to have to run multiple cable types to an array" or, “I don’t want to have to distribute heavy-duty power cables to each speaker enclosure."
This particular argument can get the legs kicked out from under it pretty quickly when you view it through the lens of the number of transducers and amplifiers required to construct a large–format, high–powered single acoustic source line array. Like everything we do in live production, there must be a “weighting” of practicality when considering any system design. For example, let’s consider Anya as a benchmark, given that it was the first active system of this ilk to meet the density requirements for a full–bandwidth line source.
Do so and you quickly realize the thought of having to pay for custom manufactured, single use case multi-core speaker looms, capable of delivering ground-based amplification to 22 transducers in the air for a single enclosure, and you quickly realize that this canbe an expensive, very impractical exercise, Especially so when you consider how far speaker looms or multicore can be asked to travel in today’s large scale touring environments. At that scale, damping factor challenges for transducer control and high-frequency roll-off become a reality.
Secondly, from an expense perspective, a side-by-side comparison of custom-built multi-way speaker looms against custom-built Socapex power distribution looms plus Cat6e multi-way breakouts, the active system can tempt you into thinking the active design is more expensive. But when you compare costs, don’t forget to add the cost of amp racks, custom rack panels, and rack cabling infrastructure to the passive design in aggregate expense total. Once you do, the scale tips heavily in favor of active enclosures.
"Including the amplifiers and DSP in the enclosure makes the cabinet too heavy to rig and fly."
It’s certainly factual to say that increasing transducer density and adding other drive componentry to an enclosure ensures an increase in weight. This is a narrative that has dogged nearly all active designs, and ADAPTive has not been an exception. But this is generally because of some selective comparison of the components of the system, enclosures, cabling, etc.
But if you drill down and analyze the overall weight measured against performance, it tells a VERY different story. Firstly, it’s not accurate to simply compare the weight of single enclosures. I’ll use Anya, a dual 15” model compared to a competitor’s popular dual 15” model. The passive version of the dual 15” offers 9 transducers. A single ADAPTive enclosure offers 22 transducers, 22-amp channels, and 22 DSP channels. The fact that these two enclosure designs are only 40lbs apart is a testament to the engineering in Anya. But here is the more important metric to examine. Because of the density of drivers and amps, with equal cabinet counts, an ADAPTive array will yield about 30% more SPL capability. And because of the density in design, it also offers far superior coverage capabilities. Let’s compare the two 12-cabinet arrays’ capabilities. If you match the performance metrics between the two arrays, conservatively, you end up with at least 2 fewer Anya enclosures. By doing so, the weight advantage swings to the active Anya enclosures by about 226lbs (103kg).
But even that’s not the entire story. Remember, Anya’s weight includes amplification – so of course, conversely, with Anya, there are no amp racks in the truck or on the ground. There’s no need for labor pushing amp racks to the truck or clogging up your warehouse and prep area. By performance matching the enclosure count, you yield a net 732lb (332kg) advantage to Anya, and you also just gained an entire row of truck space. That translates to “countable” dollars for a tour accountant, resulting in fuel savings of .25% per gallon of fuel for every 1000lbs you remove from your travel weight.
So, you, as the client, would be well served to evaluate weight in the aggregate, rather than simply looking at enclosure weight and proclaiming, “That system is too heavy.” In actual fact, the opposite is true. No, seriously, you can look it up. 🙂
“If there is an amplifier failure in the air, I can’t get to it or address it.”
While this is factual from a practical point of view in terms of physically changing the amplifier out, it also does not tell the whole story. Consider this: in many passive array designs, a single amplifier channel often addresses 2, maybe even 3 or more transducers for enclosures. A failure here would be extremely impactful to array performance and would demand the physical change–out of an amplifier in a rack. All good, right?
That rack is likely positioned on the ground and would likely require the physical un-racking and re-racking of an amp before returning it to service, unless you are carrying spare amplifiers in each rack. (which many tours do). Additionally, if this is a processed amp, the correct settings from the failed amp must be recalled, which means powering it up and selecting the right presets before delivering audio to the array. If it’s a networked amp, the SE will need to properly address and access it on the network. This is all hardly a “quick” process. Given the array performance damage, a change during show time carries added urgency and risk, given the added possibility of disrupting power or even the network to the entire rack in your efforts to bring a single amp back online. So, yes, accessible but far from graceful and safe.
Conversely, specifically with enclosures that offer ADAPTive density, mitigation of the failure of a transducer, amplifier, DSP, or even an entire cabinet is relatively painless and certainly fast by comparison. Just as importantly, it is safe for the live performance. For example, with ADAPTive systems, Resolution software will alert you to a transducer, amplifier, or DSP failure and provide a means to “heal” around the failure and recalculate the vertical polar with no loss of coverage and minimal loss of headroom. You can achieve this nearly as fast as you can hit the enter key on a keyboard. By the way, no flashlight or headlamp required.
“Active systems are more at risk to weather (rain) because they are more exposed than rack mount amplifiers and DSP that are stationed on the ground.”
I must admit I chuckled a little bit when I read this one, because the first pictures that ran through my mind were of completely submerged amplifier racks. Yes, I have been in the business long enough to have actually witnessed this exact scenario on more than one occasion, believe it or not. But I don’t want to come off as disingenuous here. Of course, that type of occurrence would be exceedingly rare. There’s no side-stepping that an array of active speaker enclosures hanging out in the open, exposed to wind, rain, and who knows what, would not be uncommon in today’s festival and stadium environments. So yes, viewing this scenario through the lens of “exposure” makes this question challenging to address and overcome by comparison to passive enclosures, but certainly not insurmountable. In my mind, it is nothing that competent engineering cannot address. Fortunately, the industry has developed well–vetted IP data and ratings. As such, they’ve created standards with appropriate ratings to guide designers in building environmentally protected products with high reliability. That said, with EAW ADAPTive products among the earliest to attempt this at concert sound and fixed installation tiers, we are in the deep end of the experience pool regarding weather–protecting products and deploying water–mitigation strategies in our designs. While we feel we’ve done a solid job with this aspect of design, there is always room for improvement, regardless of whether we’re talking about active or passive designs. The industry’s commitment to improvement across all live sound technologies is ongoing.
“Active systems are way more expensive than passive systems.”
As I alluded to in the weight comparison, in the case of EAW ADAPTive systems specifically, it’s logical and factual that a loudspeaker enclosure that offers that level of driver density and integrated amplifiers and electronics would be more expensive in a line-item setting, while comparing “box to box” with a competitor. But again, further analysis through the lens of aggregate systemcosts tells a very different story. Let’s stay on the comparison of Anya with the popular dual 15” offering. If you match the enclosure count in the systems, Anya would represent approximately +3% increase in cost. But the value that 3% generates is pretty impressive.
- 30% increase in output capability.
- Superior coverage capability
- Lighter to transport
- A full row of truck space recovered
If the rigged weight is a deal breaker, you would move back to parity on performance and active regains the advantage by retaining all the positive attributes shown above and more in terms of weight reduction in the truck. It’s an interesting one to dig into and analyze, because the more you dig, the more appealing active becomes by comparison.
Consider, if you will, how far ahead of its time the first ADAPTive system, Anya, was when it arrived. At the time of its release, all of the technology used in it was a leading-edge offering. Small, very high-powered HF transducers at a density capable of completing a full bandwidth single acoustic source design. It deployed the latest in Class D amplification and DSP capabilities. The system offereda fully redundant Dante-networked audio transport and control interface. (Dante had only been on the scene for about 4-5 years at that point). Infrared sensing on all enclosures for automatic detection from a highly advanced EAW software platform called Resolution. A software platform that remains unrivaled in its capabilities to this day.
Given this kind of leading-edge technology and engineering, it would be natural to expect it to be more expensive – especially when compared to a single conventional passive enclosure and amplifier package. But consider pricing in the context of where we are now today, and the realization is stark. After nearly 15 years on the market, ADAPTive products remain the only fully active, full-bandwidth single acoustic-source enclosures and arrays available. In fact, the price of modern passive systems continues to climb, making ADAPTive products significantly more price-competitive than they were at launch.
It’s worth noting that EAW had one of its best financial years in 2025 since the company’s inception. Much of that success lay at the feet of ADAPTive sales revenue. Currently, this level of success and adoption is nearly invisible to the touring industry. But ADAPTive and Resolution software development marches on, still as relevant, if not more so, today than when it was unveiled in 2013.
