QUICK AND DIRTY AUDIO MATH

QUICK AND DIRTY AUDIO MATH

We are faced will kinds of thing to compare or calculate everyday in audio. We could of course pull out a calculator to find the answer (assuming we know the proper formula to use), or we can get “close enough” for practical usage, by simply understanding some basic concepts and a very few numbers or relationships. Hopefully this will help some of those who are “math challenged”, by making it simple.
For the math inclined: dB (watts)=10log W1/W2 dB(distance or volts)= 20log D1/D2
Most of the time we are not interested in exact numbers, but rather the dB relationship between the numbers. Once you start to think in terms of the dB differences, rather than the actual numbers, things begin to become clearer and make more sense.

WATTAGE: Yes, more watts is louder (assuming all other metrics stay the same), but does it matter, and how much of a difference does it make or how loud will it get? If you can remember that twice or half the power is a 3dB change, and can count the number of zeros in the difference (each 0 accounts for a 10dB increase), you can easily figure out, close enough) in your head things like the dB gain of a loudspeaker, differences is amplifier sizes etc. Let’s say that a loudspeaker has a power handling of 2000 watts. How much louder is that than the rated sensitivity. You should be able to answer that in about 2 seconds. First of all, 1000 has 3 zeros in the number, so that is 30dB greater than 1 watt. (1 second). Since 2000 watts is twice that of 1000 watts, that is 3dB. So 30+3=33dB. (2 seconds). So if a loudspeaker has a sensitivity of 103dB with 1 watt, then it should produce 136dB with 2000 watts applied. YES, there are a number of other factors, but we are keeping it simple here, for the basic simple math.

Let’s go the other way. A loudspeaker has a power handling of 250 watts and a sensitivity of 98dB with 1 watt applied. How loud can it get? You can approach it two different ways. Since 250 is a little more than twice 100, and since 100 has 2 zeros, 100 watts is a 20dB gain over 1 watt, and 250 watts is a little over twice 100, so it is a little more than 3dB extra, the answer would be a little over 23dB gain. Or we could go backwards and see that 250 is ¼ of 1000. Since we know 1000 watts is 30dB gain (again over 1 watt), and half that (500 watts) is 3dB less, and half of 500 is 250, then we subtract 6dB (3+3) from 30 and end up with 24dB gain. 24dB is a little bit more than 23dB (as done the first way) So when looking at the wattage of amplifiers, generally a useful change is considered 3dB, so twice the wattage (assuming the loudspeaker can safely handle the extra power). So while the difference between a 3000 watt amplifier and a 4000 watt amplifier may at first seem like a lot, it is no different than the difference between a 3 watt and 4 watt amplifier, in terms of dB change. A 3dB change to a 3000 watt amplifier would be to go to 6000 watts. So don’t think in terms of ONE THOUSAND WATTS, think of it as just a little tad bit more than the current 3000 watts. It is generally not worth discussing. Technically it is 1.25dB louder, but turn up a signal 1.25dB on a digital console or DSP and see if that increase of level is worth spending money on.
DISTANCE from the source.

The same things happen when thinking of distances, but the math is a little different. Double or half the distance = 6dB change in level. Now that assumes that you are not too close to the source. When you are in the “nearfield” (this changes with different models) of a loudspeaker, these rules do not apply
So let’s say the FOH mix position is 50’ from the loudspeakers, and you want to know approx. how loud it will be at the rear seats, which are 200’ away If the SPL is 100dB @ FOH. There are number of other variables (humidity, temp etc) involved in sound traveling through the air, so we have to say “approximately”. The thought process would be: Going from 50’ to 100’ would be a loss of 6dB, and going from 100’ to 200 would be another 6dB, so a total loss of 12dB from 50’ to 200’, or 88dB at the seats 200’ away.

HOWEVER-this is “assuming” that the sound is pointed along the same axis as the ground, and started out at head height, and often it is not. So the actual numbers could vary a bit. The actual numbers could be more or less loss, depending on things such as height of the loudspeakers, where they are aimed, pattern of the loudspeakers and so forth. But it is a good starting point.

And it works for longer distances also. The difference between 500’ and 1000’ is 6dB. That could be good or bad, depending on “whose side” you are on. If you trying to cover a long way out, that is a good thing, but if the neighbors are there, it is a bad thing, you would want more loss over distance.
Ten times or 1/10th the distance would be equal to a 20dB change in SPL.

So with a little understanding, and just a couple of numbers to remember, you can get “close enough” for audio, without having to grab a calculator. Understanding the relationships of “all things audio” is as important as the detailed specifics. Often some quick “math in the head” will do the job.

Bartley Christian Church becomes the first J7 install in Singapore.

Bartley Christian Church becomes the first J7 install in Singapore.

Bartley Christian Church had been looking to upgrade their audio system since 2018. After two years of research and speaking with existing users, they eventually made the decision to go with Danley Sound Labs. Soundsmith Solutions, Danley distributor for Singapore and Malaysia, were tasked to design an audio system that would provide even coverage for their 1,200 seat auditorium.

The existing system, being 10 years old, was showing its age and struggling to keep up with the higher impact music being played in church. Additionally, the way the previous system was designed and installed it interfered with the line of sight to the projection screen. Some seats in the house had an obstructed view of the stage and screen.

Soundsmith Solutions had to design a powerful system with a fairly small footprint to meet the growing needs of the church. The J7’s proved to be the right box for this hall. The system now consists of two J7s, two SH95s, for down fill, and two SH46s as side fills. Also, four TH118XL, two per side, were placed behind the loudspeakers and six SH-Mini were also used as front fills. This design proved to be the winning combination for Bartley Christian Church, the measured results showed a tremendous improvement over the previous loudspeaker system and it delivers vastly greater intelligibility with an average of 0.76 STI achieved across the hall.

DANLEY SOUND LABS JERICHO J7s GIVE PENSACOLA CHRISTIAN COLLEGE A NEW LEVEL OF PERFORMANCE

J7s GIVE PENSACOLA CHRISTIAN COLLEGE A NEW LEVEL OF PERFORMANCE.

Pensacola Christian College teaches over 4,500 students at its beautiful Pensacola, Florida campus. Its students gather in the nearly 6,000-seat Crowne Centre frequently for community-building, events, chapel, for concerts, and church services on Sunday morning, and Sunday and Wednesday evenings. Sunday morning services are recorded and broadcast as “Rejoice in the Lord” on the Daystar Television Network. All Pro Integrated Systems, a locally-based AV integration firm with international reach, recently replaced a tremendous number of loudspeakers, subwoofers and amplifiers in the Crowne Center with a vastly smaller number of Danley products, including Danley Jericho J7-95, TH118XL subwoofers and DNA-series amplifiers with onboard DSP and optional Dante connectivity.

“We put the original sound system in the Crowne Centre when the building was new almost twenty years ago,” explained Scott Vegte, director of sales operations at All Pro Integrated Systems. “It performed well for technology of the time, but it had passed its sunset age. Components were failing, and the manufacturer was no longer making replacements. We started talking about upgrading in 2018 and moved into planning in 2019. Because the Crowne Centre gets used almost daily, we knew we would have a short window to do the actual installation. Everyone involved knew there would have to be plenty of planning to make the installation smooth and successful.”

“We traveled with the team from All Pro to InfoComm 2019 in Orlando to ‘go shopping’ for possible replacement systems,” said Greg Moses, TV and DVD production director at Pensacola Christian College. “We listened to five of the biggest names in high-end live sound systems. Danley was one of them, and we were thoroughly impressed with their presentation at InfoComm. They showed us a huge number of consistent-sounding products to fit different situations.” Moses and his colleagues invited the top contenders to a shoot-out at the Crowne Centre in the fall of 2019, and the Danley team, including President Mike Hedden, brought their A-game: the Danley J7-95, which is capable of continuously delivering 141dB SPL in a 90- by 50-degree coverage pattern with studio-monitor-level fidelity. Danley was the unequivocal winner of the shootout.

“Point source is really the way to go when you can long-throw,” said Chris Wickizer, systems designer with All Pro Integrated Systems. “And Danley’s point-source designs are excellent. They sound natural even when they are running flat.” As it turns out, Moses and Pensacola Christian College already had experience with Danley. “We’ve had Danley subwoofers in the Arlin R. Horton Sports Center for five years now, and we drive them hard for special events,” Moses said. “They can rattle the place! They sound fantastic. In addition, we put a couple of Danley GO2 8CX loudspeakers in our 100-seat theater. They were a night-and-day difference! We’re very pleased. And we’re also very pleased that Danley manufactures all of its products right here in the USA.”

After the clear results of the shootout, Wickizer worked quickly to design a Danley system for the Crowne Center that would give the college plenty of horsepower, even coverage and superior intelligibility. In addition, he worked within the framework of the existing system to minimize the installation time, including the preservation of fabric-wrapped speaker enclosures that retain the visual aesthetic of the previous system. The new main system replaces fifty loudspeaker components with just eight Danley J7-95 Jericho Horns and a pair of Danley SH46s for side fills. The Jericho Horns are arranged in four hangs of two boxes each – one for the main floor and one for the balcony. Four Danley TH118XL subwoofers hang from a center scrim and provide the same thunderous (but undistorted!) low end that the college is so happy with in their sports center arena. Although the eight Jericho Horns cover the vast majority of seats, fifty-four distributed Danley SH95 loudspeakers replace the speakers in the under-balcony area. In addition, eight Danley SHmini loudspeakers fire from the lip of the convertible stage for front fill as needed.

On top of the sharp reduction in loudspeakers, All Pro replaced sixty-six old amplifiers with just thirteen Danley DNA-series multi-channel amplifiers, seven four-channel DNA 20k4 Pro models, five eight-channel DNA 10k8 Pro models, and one eight-channel DNA 3k8 Pro model. Together, the thirteen amplifiers provide seventy-six amplifier channels and nearly 200,000 Watts of power. All of the Danley amplifiers use onboard DSP for modest loudspeaker and subwoofer conditioning, and all include optional Dante inputs for simplicity and fewer conversions. As part of the installation, All Pro also upgraded the Crowne Centre FOH and broadcast consoles from Studer Vista 9 to Studer Vista X.

“The new Danley system is remarkably better than our old system,” Moses said. “Everyone who has heard it says that the sound seems to be coming from right in front of you. It’s very intimate and pleasing even though the Jericho Horns are fifty feet off the floor and one hundred feet away! At the same time, it’s not overpowering. We love the improved efficiency. With Danley we have far fewer loudspeakers and amplifiers to worry maintain. The coverage is perfectly even from front to back and from side to side. There are no dead spots or hot spots, no dips or lags. Even though I know exactly where the transition points are, I can barely detect them. Critically, the intelligibility is fantastic – everyone can understand exactly what’s being said!”

Sensitivity vs Wattage

Sensitivity vs Wattage

 

Many people think loudness is easily determined just by watts… more watts = louder.  Actually, other factors must be considered to determine the speaker loudness, and the biggest of them all is sensitivity. Sensitivity represents what SPL a loudspeaker can produce with a given input level.  It is always measured on axis of the loudspeaker.  A loudspeaker with a higher sensitivity will produce more SPL with less distortion for the same given input level.  This also means greater SPL with less power being pulled from the wall. Similar, but not the same, is efficiency. Efficiency is how well a loudspeaker converts an incoming signal to sound energy, radiated in all directions.  For this article, we will concentrate on sensitivity.

Let’s start by considering “dB” (decibel) differences.  3dB is considered the smallest change in level that most people can detect under normal listening conditions. For a 3dB increase in SPL, you need to double the watts.  Going from 1000 watts to 2000 watts, produces the same increase in SPL as going from 2 to 4 watts, as does 50 to 100 watts.  It is NOT the actual watts that are important, but rather the ratio of the watts.  This is why thinking in terms of dB is more important than actual watts.

When looking at loudspeaker specs, it is a combination of power handling and sensitivity that gives a better picture of how loud a particular loudspeaker will be.  Of course, this loudness says NOTHING about what it sounds like.  A piece of sheet metal through a saw is really loud, but doesn’t sound too nice to most people.  Consider two loudspeakers with roughly the same frequency response. Loudspeaker A has a 2000 watts capacity and sensitivity of 103dBSPL.  Loudspeaker B has a 3000 watts capacity with a sensitivity of 100dBSPL.  Assuming all other factors are the same, which one can get louder?  Of course, loudspeaker A will be louder with the same input level due to higher sensitivity, but, let’s do some math for maximum SPL.  First, convert the wattage capability to dB gain. The formula is: dB gain=10log watts X/watts Z . 

Loudspeaker A:   33dB=10log2000/1* (Assuming 1watt sensitivity).   So, add the sensitivity of 103dB + 33dB power gain to get 136dB max continuous SPL

Loudspeaker B:   34.8dB=10log3000/1* (Assuming 1watt sensitivity) So, add the sensitivity of 100dB + 34.8dB power gain to get 134.8dB max continuous SPL.

Note: We could also have used voltage capacity and drive voltage to come up with the same answers.  The voltage formula is: dB gain=20log Voltage X/Voltage Z.  We are just saving a step by not having to convert the wattage to voltage.

The moral of the story is You MUST look at the dB differences, NOT the simple watts number. Sensitivity often makes a greater impact than watts on the total SPL. Higher sensitivity can mean cost savings in terms of amplifier power, wall power, and cable size.  

Scott Howard

Employee Spotlight

This month we are featuring Scott Howard.  Scott joined Danley last year as a market specialist for both HOW (House of worship) and Studio and Recording.

As a part of our sales team growth, Scott will be adding responsibilities to his plate, directly supporting our dealer base in North Alabama, Tennessee, and North Carolina.  Based out of Nashville, Scott has many connections in both the house of worship and the country world after spending 20+ years and, over 2 million miles, on a tour bus. When he’s not spending time with his beautiful family, he’s enjoying the outdoors by way of hunting or fishing, and in the fall, you can find him cheering on the Tennessee Titans. 

Studio 2

Introducing the Studio 2 Premium Reference Monitor

✦ Self-Powered w/ on board processing & Synergy Horn™ passive network
✦ Compact & powerful
✦ Coaxial mid/high
✦ Long Excursion Woofer
 

Tom Danley, one of the most innovative loudspeaker designers in the industry today and recognized worldwide as a pioneer for “outside the box” thinking in professional audio technology has turned his passion towards the premium reference monitor. The Studio 2 is the latest release in the Studio Series following last year’s Studio 1 and Studio Sub products. The Studio 2 shares the same mid/high coaxial design as the Studio 1 but adds a 10” long excursion woofer and is self-powered featuring digitally balanced XLR inputs as well as RCA inputs. The Studio 2 is available now.

“People should really pay attention to these Danley Studio monitors,” Ratcliffe said. “They’re going to make a serious dent in the studio monitor industry! We love them! Using Tom Danley’s creative genius, they rely on just a single driver and give a detailed picture of everything that’s happening in the mix. They have incredible depth, they’re incredibly smooth and we can monitor all day long and never feel fatigued. A good mix on the Danleys translates anywhere.”

-Andrew Radcliff | Tweed Recording 

Check out Tweed Recording
Special Thanks to Cathy Weeks for the great photos! 

St. Marks School

Full Campus Update

ST. MARK’S SCHOOL OF TEXAS SWITCHES OVER TO DANLEY SOUND LABS CAMPUS-WIDE: FOOTBALL STADIUM, BASKETBALL GYM, WEIGHT ROOM, AND LOCKER ROOM
 

With roots stretching back to 1906, St. Mark’s School of Texas is a prestigious boys day school in Dallas. In addition to rigorous and diverse academics that prepare students for influential careers, St. Mark’s is well-known for its athletics. The St. Mark’s Lions compete in the Southwest Preparatory Conference, and nearly nine out of every ten students participate in at least one varsity sport. Impressed by the fidelity and impact of a Danley Sound Labs demo, school officials asked the integration experts at Dallas’ Romeo Music to design and install Danley systems at the football field, the basketball gym, the weight room, and the locker room. When an EF-3 tornado destroyed the recently-completed systems in the gym and locker room, Romeo Music and Danley Sound Labs “moved heaven and Earth” to rebuild the sound reinforcement system in an alternative gymnasium in time for the start of the basketball season.

“It was about a year ago that we first provided a series of Danley demos at St. Mark’s football field,” explained Kevin Deal, manager of integrated systems and accounts at Romeo Music. “Their existing system had broken components and an overall ‘honky’ sound, and they were working hard to find a loudspeaker manufacturer to install not just at the football field, but throughout campus. We’ve had success with Danley in the past. Danley boxes offer excellent sound quality and plenty of output. Importantly, the total cost of a Danley system is significantly less than anything comparable from other manufacturers.”

The Lions play football and track at Hunt Stadium, which seats approximately five-hundred people. It has a large home bleacher section with a building immediately behind it. The smaller visitors’ side is topped by the press box, and additional field space extends beyond the visitors’ side. The Romeo Music installation crew placed five Danley OS80 fully-weatherized loudspeakers in an exploded line on the side of the building behind the home bleachers. Four of the OS80s angle slightly down to cover the home bleachers, and the fifth fires across to cover the field itself and the visitors’ side. A beefy Danley BC412 subwoofer placed atop the building behind the home side bleachers fills out the low end to deliver a rich, full-frequency experience. 

Two Danley OS12CX fully-weatherized loudspeakers on delays above the press box cover the additional field space, and two more OS12CXs had covered the concession area until it was destroyed by the tornado (those speakers were recovered and will be reinstalled when the concession area is rebuilt). St. Mark’s staff operate the system from a Mackie 1604 on the visitors’ side press box. The mixer feeds a Xilica QR1 DSP which sends signal to the main speakers on the home side via a Dante run using fiber under the field. One Danley DNA 10k4 Pro and one Danley DNA 5k4c provide a combined eight channels and 15,000 Watts of amplification, onboard DSP (with Danley model-specific presets), and optional Dante connectivity. 

“David Dini, the Headmaster at St. Mark’s School of Texas, is very particular about what he has on campus,” Deal said. “The Hunt Stadium project was a huge success, and so we went forward with Danley designs in the Hicks Athletic Center for basketball and volleyball, the Mullen Fitness Center weight room, and the locker room. Once he was familiar with Danley’s sound, he wanted it everywhere.” The gym used six Danley SM60F loudspeakers and one Danley TH118XL subwoofer powered by an eight-channel Danley DNA 10k8 Pro amplifier. The weight room uses three Danley Go2 8CX loudspeakers and one Danley TH112 subwoofer powered by a QSC amplifier. The locker room used two Danley Cube loudspeakers and one Danley THmini subwoofer powered by a QSC amplifier. 

Toward the end of October and just 72 hours after completing those systems, an EF-3 tornado ripped through Dallas and destroyed the concession stand and the Hicks Athletic Center, among other things. Fortunately, no one was injured. With the start of basketball season just weeks away, the school decided to shift varsity activities to Spencer Gymnasium, which had previously been used for the middle school and didn’t have a sound system at all. “There was only a three-week window,” Deal said. “I contacted Danley and explained the situation. The team at Danley and my installation crew moved heaven and Earth to deliver and install a basically-identical system in Spencer Gymnasium. We finished commissioning with ten minutes to spare before the first basketball practice!” 

the State of HOW

As we continue to explore the unchartered waters of this Covid-19 pandemic, audio providers look for new and effective ways to better serve the House of Worship market.

The State of House of Worship

As we continue to explore the unchartered waters of this Covid-19 pandemic, audio providers look for new and effective ways to better serve the House of Worship market. We have all faced challenges caused by the current state of social distancing, shelter-in-place, and businesses shutting down. Houses of Worship were among the first that were instructed to not gather in large groups. This has forced everyone in the A/V business from manufacturer to integrator, to improvise and look at different ways to achieve their goals. The encouraging news is that these trying times have created unique ways for A/V companies to assist and offer solutions to our Houses of Worship.

There are an estimated 350,000 to 400,000 HOW buildings in the US alone. Not all have progressive services utilizing audio video, and lights (AVL), but research shows that about half do, and many more are moving in that direction. That represents a sizable vertical market that is looking for solutions. With churches having to close their doors to groups of more than just a handful during this time, I am seeing not only more streaming services than ever before, but also “Park and Preach” or “Drive Up” services. These new worship formats allow opportunities for AVL companies to provide expertise in setting up streaming scenarios for churches, advise on lighting and camera choices, or even helping provide portable PA solutions for congregations that are meeting in their parking lots in cars. I have seen integrators offering free tech support to churches that are either new to the streaming world or building systems for churches that have never taken advantage of streaming before. There are numbers of churches reaching out on social media platforms daily asking for advice as they try to maneuver through the AVL challenges that they are now facing. Especially now, there is an increased awareness of how important AVL is in the HOW environment. This is an opportune time to show how good quality AVL will make a positive impact on a worship service. An investment of time and knowledge made now with these congregations, will remain with them for years to come. Every contact made with a local church could start a relationship that will make you their “go to guy” when they are considering services or products. I am encouraged by the coming together of companies and brands to work towards finding better solutions for our Houses of Worship.

Danley Sound Labs is fortunate in that even in these days of imports being slowed down or halted, our USA made products allow us to continue production and installation. We have OS products in stock and are still being manufactured even during the current situation. Being able to offer short lead times is only one of many great selling points for the Danley line of products, and I anticipate the USA made status to be something that American buyers will be looking for more and more. Our engineers are continuing to develop new products and systems and I foresee that even through these uncertain times, Danley will continue to be a leader in loudspeaker innovation.

BORN FOR CINEMA

BORN FOR CINEMA

Having entertained and educated over 175 million visitors since opening in 1933 on the former site of the 1893 World’s Columbian Exhibition, Chicago’s Museum of Science and Industry (MSI) has long stood as the vanguard of museum programming. Forever reinventing itself, the museum built an Omnimax theater – the city’s only five-story, domed IMAX venue – in 1986. While it has continued to draw capacity crowds in recent years, the theater was due for an overhaul, both because equipment was failing and because its technical specs were falling behind the times. Today, a fresh set of Danley loudspeakers and subwoofers have revitalized the sound system with impact and truthfulness that were simply unimaginable even ten years ago.

The IMAX experience is one of immersion, and the Omnimax variant (recently rebranded “IMAX Dome”) is its fullest realization. A standard IMAX theater, of which there are more than 300 in the world, features a screen that is at least 72 feet wide by 53 feet high. The Omnimax concept uses special recording lenses that distort the captured image and a playback system that reverses this distortion to project on a wrap-around dome. As a result, the screen takes up the viewer’s entire field of vision.

But as any intro textbook on sound for film will tell you, viewers consistently rate the overall quality of a theatrical experience more by sound quality than by visual quality. For some reason, our brains are more forgiving of visual distortions than of auditory distortions. On this score, MSI was struggling. Only four of the six audio channels were working; the components of the once-high-end loudspeakers were tired and inaccurate; and the playback system would intermittently drop audio entirely, requiring the projectionist to make a frenzied run downstairs to reseat antiquated sound cards.

Their expectations for audio performance were exacting, and an exhaustive search of the “latest and greatest” in loudspeaker technology led them to Danley Sound Labs. Danley’s patented Synergy Horn (SH) loudspeaker and Tapped Horn (TH) subwoofer designs obviate the fidelity-compromising tradeoffs that are inescapable using traditional approaches and thus deliver more natural, phase-coherent reproduction – even at high SPLs.

Noted Danley President Mike Hedden, “When Tim Olgetree at MediaMerge called, he requested a loudspeaker with the sonic characteristics of our flagship Danley SH-50. But instead of the SH-50’s 50- by 50-degree dispersion pattern, he needed a 90- by 60-degree dispersion pattern to fit the theater. Tom Danley and I discussed the details and ultimately the CSH-1196 was born with pattern control down to around 100 Hz together with a flat phase response and flat magnitude for three pass bands. From the initial request to shipping the initial CSH-1196 was only six weeks.”

The new speakers replaced the six old speakers in a one-for-one swap. In addition, four Danley CTH-50 subwoofers generate the low-end rumble for avalanches and the like. Hedden summarized, “Our loudspeakers, especially ones as large as the CSH-1196 have tight pattern control down to around 100Hz and don’t energize the room like other systems. We deliver extremely high direct to reverberant ratios that translate into clear, phase-coherent sound to the audience, and to the audience only. The fidelity is truly remarkable, so much so that, to the listener at the Omnimax, the speakers effectively disappear.”

SPEAK WITH AN EXPERT

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Screen Channel
The CSH-1196

Subwoofer
The CTH-50