Line Array Coverage Calculator: Angle, SPL and Distance Tips

2025-09-21
Practical guide to using a line array coverage calculator for optimal angle, SPL and distance planning. Learn formulas, splay tips, real-world examples and why T.I Audio line array speakers fit pro events.
This is the table of contents for this article

Line Array Coverage Calculator: Angle, SPL and Distance Tips

Quick overview of line array speakers and coverage goals

When planning a live event, using a line array coverage calculator helps you predict where your line array speakers will throw sound, how much SPL you can expect at given distances, and which vertical or horizontal angles to set. This article gives concise, practical tips for angle selection, SPL vs distance calculations, and real-world adjustments to help your team get reliable results fast.

Understanding sound propagation for line array speakers

Point source vs line source behavior and why it matters

Sound propagation rules change depending on whether the system behaves like a point source (single loudspeaker) or a line source (stacked array). For line array speakers, the array approximates a cylindrical wavefront over a certain range, reducing the rate of SPL loss with distance compared to a single speaker. Knowing which model applies at which distance is the first step to accurate coverage calculations.

Attenuation comparison: point source, real line array and ideal line source

How SPL drops with distance for different sources

Below is a clear comparison to use in your calculator and planning. Each paragraph and refers to line array speakers to keep practical focus.

Source type SPL change per doubling of distance Typical behavior for line array speakers
Ideal point source (spherical) −6 dB Single speaker or small cluster at far-field
Ideal line source (cylindrical) −3 dB Long arrays in their near/transition field
Real-world line array speakers Between −3 dB and −6 dB Depends on array length, frequency and audience geometry

Calculating SPL change: simple formulas for your calculator

Use quick SPL math for line array speakers

Two formulas are most useful in a calculator. For spherical (point) spreading: ΔL = −20 * log10(r2 / r1). For cylindrical (line) spreading: ΔL = −10 * log10(r2 / r1). Use the cylindrical formula as a starting approximation for line array speakers in the array's near-field. Remember to switch to spherical behavior for far distances or when the array is short relative to the throw.

Choosing vertical and horizontal coverage angles

Vertical angle selection tips for line array speakers

Vertical coverage determines how you split energy between the front rows and the back rows. Typical vertical module splay settings are small: 0°, 2°, 4°, 6° or larger, depending on audience rake and distance. For long throws use tighter splay between modules to create a more cylindrical wave. When covering short venues, use wider splay and aim lower so the near field isn't overloaded. Always verify with a coverage calculator that models audience plane distances and listener heights for line array speakers.

Horizontal angle selection tips for line array speakers

Horizontal coverage is controlled primarily by the cabinet horizontal dispersion pattern and box count. For FOH control, choose speakers with matched horizontal directivity (e.g., 90° or 110°) and set arrays to avoid spill onto reflective side walls. When the venue width exceeds the array’s horizontal throw, use delay fills or fill speakers to keep SPL consistent across the audience.

Practical inputs for a line array coverage calculator

Key parameters to enter for accurate results

To get useful predictions from a coverage calculator for line array speakers, input these parameters: array model and cabinet directivity, number of elements, inter-cabinet splay angles, FOH height, audience plane slope, listener height, desired SPL at target points, and frequency band or weighting (A or C). Including audience absorption and ground reflections improves accuracy.

Interpreting calculator outputs and safety margins

How to read SPL contours and set conservative limits

When the calculator shows SPL contours for line array speakers, focus on the usable frequency-weighted SPL across the audience plane, not just low-frequency output. Apply headroom of 3–6 dB above predicted levels for dynamic peaks and system losses. For concerts, SAS (sound level limits) may enforce maximum SPLs; plan to meet local regulations while preserving clarity.

Real-world factors that change calculated coverage

Audience absorption, temperature, and ground effects

Human bodies and seating absorb mid and high frequencies; a dense crowd can reduce SPL at the back by a few dB compared to an empty venue. Temperature gradients and wind can bend sound, especially outdoors. Hard reflective surfaces create comb filtering or hotspots. Always measure with an SPL meter or RTA in system tuning to confirm the predictions for your line array speakers.

Tuning and optimization techniques

Splay schedules, EQ, and delay fills for consistent SPL

Use splay presets for the intended coverage zone: tighter splay for long rows, staggered splay for stadium-style stepped seating. Apply gentle low-mid EQ corrections to equalize the array’s natural frequency response across distance, and use delay fills to align SPL and timing for outfill speakers. For critical shows, run a walk-through measurement at multiple listening positions to confirm even coverage from your line array speakers.

Example calculation: small outdoor festival using line array speakers

Scenario inputs and predicted SPLs

Scenario: two hangs of 8× line array speakers per side, each cabinet rated 135 dB peak output at 1 m (single cabinet theoretical), array mounted 6 m high, audience plane from 7 m to 50 m. Using cylindrical spreading approximation for the main energy between 7–30 m and spherical for beyond 30 m, expected midband SPL at 30 m is approximately 6–9 dB lower than at 15 m depending on array coherence. Below is a concise table summarizing approximate values computed with the formulas in this article for planning; always verify with measurement before showtime.

Listener distance Approx SPL drop from 1 m (ideal) Estimated midband SPL (dB, relative to cabinet rating)
15 m Using cylindrical approx: −10*log10(15/1) ≈ −11.8 dB ~123 dB (peak, per array baseline)
30 m Doubling distance from 15 m, expect −3 to −6 dB → additional −3.0 dB (ideal line) to −6 dB (point) ~120–117 dB
50 m Transition toward spherical spreading; total drop ≈ −20*log10(50/1) ≈ −34 dB ~101 dB (if point-like at that distance)

Why choose T.I Audio line array speakers for your events

Manufacturer expertise and product breadth

T.I Audio has 14 years of pro audio manufacturing experience in China and a portfolio that includes line array speakers, PA speakers, stage monitors, subwoofers, amplifiers, processors and wireless systems. With a seasoned engineering team and global sales presence in over 100 countries, T.I Audio designs line array speakers suitable for concerts, festivals, houses of worship and rental companies. Choosing a proven brand simplifies coverage prediction because product specs and beam patterns are documented and supported.

Checklist: using a coverage calculator with T.I Audio line array speakers

Step-by-step practical checklist before showtime

1) Select the exact T.I Audio line array model in your tool. 2) Enter number of cabinets and splay pattern. 3) Set listener plane heights and distances. 4) Include audience absorption and delays. 5) Apply realistic SPL targets and headroom. 6) Walk the venue with an SPL meter to confirm predictions from your line array speakers.

FAQ

Q: How accurate are coverage calculators for line array speakers?

A: Calculators are useful for planning but are approximations. Accuracy depends on quality of input data (cabinet directivity, splay angles, venue geometry) and whether you model audience absorption and ground reflections. Expect calculators to guide setup; always confirm with measurements and a tuning session.

Q: At what distance do line array speakers stop behaving like a line source?

A: There is no single distance — it depends on array length and frequency. Low frequencies often behave more like a point source sooner. As a rule of thumb, the array behaves more cylindrically up to distances approximately equal to the array length; beyond that, spherical spreading dominates and SPL loss approaches −6 dB per doubling of distance.

Q: Should I always aim for cylindrical (−3 dB) spreading in my calculator?

A: Use cylindrical spreading for mid/high frequencies and for distances where array coherence is maintained. For long distances or when the array is short, switch to spherical assumptions. Many calculators blend models across distance — choose that option if available for line array speakers.

Q: How do splay angles affect SPL and coverage?

A: Larger splay angles spread coverage over a shorter distance (wider vertical coverage) and reduce coherent long-throw energy. Smaller splay angles keep energy focused for long throws and create a more cylindrical field. Use the array module splay schedule to shape the coverage zone precisely for your audience plane.

Q: Can I rely on manufacturer SPL specs for coverage planning?

A: Manufacturer specs are the starting point but represent ideal conditions. Use them with real-world corrections for mounting height, audience absorption, and environmental conditions. T.I Audio’s product datasheets include directivity and sensitivity data that make coverage calculations more trustworthy.

Q: Where can I get help tuning a system with T.I Audio line array speakers?

A: Contact T.I Audio technical support or a certified local dealer for system design and on-site tuning. The company’s engineering team has over 20 years of pro audio systems experience and can assist with array presets, splay suggestions and measurement-based tuning for line array speakers.

Tags
15 inch full range speaker
15 inch full range speaker
Oscillating lamp
Oscillating lamp
15inch speaker
15inch speaker
subwoofer speaker cable
subwoofer speaker cable
Moving head light
Moving head light
wireless microphone and pa system
wireless microphone and pa system
Recommended for you

OEM/ODM professional speaker systemcustomize Manufacturers and supplier in China

OEM/ODM professional speaker systemcustomize Manufacturers and supplier in China

Tips for Wholesale stage monitors

Tips for Wholesale stage monitors

Everything You Need to Know About two 15 inch subwoofer box

Everything You Need to Know About two 15 inch subwoofer box

OEM/ODM passive line array speakersbest Manufacturers and supplier in China

OEM/ODM passive line array speakersbest Manufacturers and supplier in China
Prdoucts Categories
Question you may concern
Customization
Can customize my own brand?

Of course, my friend.  We can help put your logo on the flightcases of goods for free, only for you.
As for product, Yes, sure, we accept OEM. If you need to customize your own logo, our minimum order quantity is ~pcs, and the cost is also different. Are you the person in charge of this project? You may want to discuss it with your team. Check it out and update our quotation after confirmation.

Products
What's new products recently?

We did investigate the market recently and have some new products to share with you.

How about the quality of your products.

T.I Pro Audio is the top audio manufacturer in China.
With over 14 years of experience in more than 100 countries around the world, 
We focus on high-quality and tech developments these years,and  our company puts 50% of its profits into updating products to win the market around the world.
All T.I. professional audio products have a 3-year warranty and lifetime maintenance.

After-sales
I don't need to order these products. I want refund.

To keep my customers safe, it's important to provide excellent customer service, deliver high-quality products, and build trust through transparency and honesty. You can also offer a guarantee to assure customers of the quality and reliability of your product. Additionally, maintaining open communication and promptly addressing any concerns or questions can help build strong customer relationships.

Solution
For covering how many people events?

Let's make a suitable plan for you according to your requirements.

You may also like
MAX215 line array speaker system

T.I Pro Audio waterproof passive dual 15 inch best line array speakers (max215)

MAX215 was born for big outdoor events, such as concerts, church, crusades, etc. With its 100% waterproof design, it can be used in strong sunlight or heavy rain without worrying about any safety problems. Max215 with LF: 2*ND15 driver MF: 2 *ND10'' Neodymium drivers; HF: 2 *ND3” Neodymium drivers. It can cover more than 5,000 people. This product was very popular after its launch because of its unique, patented appearance and perfect sound. And quickly occupy market share. Help large projects get powerful and perfect sounds.

T.I Pro Audio waterproof passive dual 15 inch best line array speakers (max215)
line array pa system

T.I Pro Audio new design waterproof linear array speakers dual 12-inch live sound outdoor concert speaker

Fully set system Pro2123 dual 12 inch line array including Pro2123+Pro218+Pro15M+Amp+Processor+Mixer+Mics with 8 tops and 4 bass,2 monitors,fully set amp,processor,mixer and wireless mics,including cables plugs,fully setting can work for 3000 people live show,DJ shows,sound events..
T.I Pro Audio new design waterproof linear array speakers dual 12-inch live sound outdoor concert speaker
Array speakers LA-2122 Main

T.I Pro Audio Waterproof Passive Dual 12 Inch Two Way Powered Line Array Speakers For Church (LA-2122)

LA-2122 uses a neodymium unit to ensure its high sensitivity, small size and light weight.The surface is black, high-strength polyurea paint.The 134dB maximum sound pressure level output makes LA-2122 stress-free in medium- and large-scale mobile performance applications.
T.I Pro Audio Waterproof Passive Dual 12 Inch Two Way Powered Line Array Speakers For Church (LA-2122)
speaker 10 inch

T.I Pro Audio professional audio speakers indoor outdoor concert speaker single 10 inch passive line array

Pro-110&Pro-118P active system setting with 4 tops and 2 bass,including mixer and wireless mic,fully setting can work for 500 people live show,DJ shows,sound events.. With 10’’ neodymium driver for LF,with 3 inch high frequancy,with 18 inch active bass,125mm voice coil for the bass to make sure the full system is very powerful
T.I Pro Audio professional audio speakers indoor outdoor concert speaker single 10 inch passive line array
Get in touch with us
If you have any comments or good suggestions, please leave us a message, later our professional staff will contact you as soon as possible.
Please enter your name not exceed 100 characters
The email format is not correct or exceed 100 characters, Please reenter!
Please enter a valid phone number!
Please enter your field_186 not exceed 100 characters
Please enter your content not exceed 3000 characters
Contact customer service