Sound Pressure Level

Proposed SPL rules changes for 2010

Following a recent meeting of the EMMA Ireland SPL rules committee, we propose to introduce some changes to the SPL rules for the 2010 season,
The proposed changes are laid out in the draft document, available for download from HERE. All proposed changes are highlighted in RED.
If you have any questions or wish to pass on queries, please This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

SPL Rules 2009

These rules were developed independently by the EMMA Ireland Judge Team.
They were designed to be used as an alternative set of SPL rules, in place of any other rules sanctioned by other organisations.
By competing under these rules, it is deemed that you agree to accept their use and will abide by any and all decisions or rulings made by Judges/Officials.
Rules are subject to amendment, please check http://www.emma-irl.com/html/spl_rules.html to check for any changes/updates.
To Contact EMMA Ireland please:

email:- This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Phone:- +447710 471044 (Outside office Hours)
Fax :-+447092 311453

SPL Rules

Why determine Classes by woofer cone area instead of power?

Policing the actual rated power of an amplifier has long been the unsolved riddle of car sound competitions.

Almost every day we’re asked questions regarding what power rating to use when determining the total output power of a competition system. Is it the RMS rating? Is it the 12-volt or 13.8-volt rating? Is it the stereo or bridged mono rating?

Power, if there were some actual industry standard by which to measure it, would have created a level playing field for all competitors. But such is not the case. What remains is confusion!

The woofer cone area Classifications are intended to remove this confusion by simply:

measuring the nominal outside diameter of the woofers in the system,
multiplying by the number of them being used,
and determining the Class to compete in by looking at where it fits in the chart at the back of this book.

It’s that Simple! We’ve even done the maths for you!

Just see the chart at the end of these rules.

The physics of a speaker are, in varying degrees, power limiting. Too much applied power & BOOM, there goes a speaker. The choices are simpler now.

Woofer cabinet design creativity will now become a greater part of the “How You Win” formula. Most woofer manufacturers offer information on which types of enclosures will render the best results with their products. Many car sound retailers are also well versed & extremely capable of building those creative enclosures.

We’ve made it easy & fun. Don’t just sit there. Go out & see how easy it is to enjoy yourself by competing in events.

Competitor Divisions

“Stock” Division

INTENT:

The intent of the “Stock” Division is to provide a category for competition among contestants that have no affiliation or support from the car audio industry; & have obtained their mobile electronic systems through retail channels.

A competitor may elect to compete in the “Stock” Division if they meet at least one (1) of the following criteria. These criteria shall also serve to define “Consumer” competitors.

The mobile electronic system(s) that they are entering into competition must have been purchased through normal retail channels. If requested by an event Official, proof of purchase (i.e. numbered sales receipt) must be available for verification.
They do not derive any income from being directly involved in the selling, installation, manufacturing, testing or engineering of car sound electronics, speakers, speaker enclosures or accessories. They do not derive an income from being paid by the publisher of any car sound related material.
They have not received any financial support or compensation for participation in this and/or similar events or promotions.

There are two (2) woofer cone area classes in the “Stock” Division:

1-260 Sq Inches
261+ Sq. Inches

The vehicle’s interior is to be kept stock looking from the trailing edge of the front doors forward. All vehicles that do not meet the following criteria will be moved to the “Advanced” or “Ultimate” Divisions. The Head Judge has the right to move the vehicle into the “Advanced” or “Ultimate” Divisions if, in their opinion, any of the following criteria is not met or is questionable.

The vehicle must have OEM style glass in all windows.
The spare wheel, or access to it, must be maintained.
The vehicles windscreen & front door windows cannot be obstructed or modified. (Having a severely cracked windscreen may result in disqualification.)
Windows that rolled up & down when the vehicle was manufactured must remain operational.
Speaker upgrades can be made in front of the “B” pillar only for sound quality purposes.
The vehicle must have its factory dashboard intact & not modified, other than possibly with small speaker builds (i.e. surface mounted tweeters.)
Factory style door panels must remain intact with the possible exception of a partial door build to house an operational driver that is smaller in diameter than the woofers being used to generate SPL.
The only acceptable kick-panel modification is the addition of partial builds to house functional drivers for the purpose of creating a better sound stage & imaging.
Competitors in the Stock Division are only allowed to use one physical amplifier for each physically installed woofer
Amplifiers mounted forward of the plane of the B-pillar may only be used to power front components.
To compete in the Stock Division the Subwoofers, Amplifier and batteries (if fitted) must be mounted within the original boot area & cannot be taller than 25 inches or the top of the standard parcel shelf, whichever is the lower of the two.
The competitor will be required to demonstrate that the entire system can be concealed by the rear seats & under the standard parcel shelf, otherwise the vehicle must compete in either the “Advanced” or “Ultimate” Divisions.
SUV’s & Vans must have the enclosure one half of the distance from the “B” pillar to the back of the vehicle towards the rear & no more than 25 inches tall.
The factory fitted headliner must be unmodified, remain intact & in its original location.
The factory floorboard must remain intact, not be reinforced or raised & must be covered in factory or OEM style carpeting.
The vehicle must have two factory, OEM style or approved aftermarket car seats mounted in the passenger compartment forward of the B-pillars. Back seats must remain in the vehicle & if applicable can be folded down. (Exception: One seat may be used if it is a full-length bench style seat.)
Seat(s) can be adjusted as per the rules but cannot be removed during testing.
All seat belts must be in the vehicle, functional & mounted to the original factory mounts.
If an after-market or modified centre console is mounted in the vehicle it must be functional. “Functional”, in the case of a centre console means that it can either provide storage space or house electronics such as equalisers, switches, or video equipment. It cannot house any speakers. If, in the opinion of the Head Judge, the console has been installed for the purpose of taking up passenger area space, the competitor will be directed to compete in the “Advanced” Division. (Suggestion: Outside dimensions of approximately 12” x 12” x 12” should avoid any possible conflicts.)
Competition in the “Stock” Division is limited to “Consumer” competitors only. (See page 2 for a definition of “Consumer”.)
In the Stock Division the maximum system voltage allowed is 14.6 Volts with the engine running.
Nothing may interfere with the correct placement of the microphone placement template. (See template placement instructions & drawing.)

“Advanced” Division

INTENT:

The intent of the “Advanced” Division is to provide a playing field for those competitors that compete with vehicles whose interiors have been altered beyond the criteria found in the “Stock” Division definitions, but lacking some of the criteria that would make competition in the “Ultimate” Division compulsory. The “Advanced” Division also provides a format where Pro’s & Consumers can compete against each other. Vehicles that meet any of the following criteria will compete in the “Advanced” Division.

A competitor will be assigned to the “Advanced” Division if they meet at least one (1) of the following qualifications. Items 1, 2, & 3 below shall also serve to define a “Pro” competitor.

The competitor derives any income, however small, from being directly involved in the selling, installation, manufacturing, designing, testing or engineering of car sound electronics, speakers, speaker enclosures or accessories. They derive any income from being paid by the publisher of any car sound related material.
Has either received, or expects to receive, financial support or other compensation for promotional consideration from any auto sound industry related person or company for participation in any event or promotion.
By their own choice.
Any participant who is unable to qualify as a “Stock” Division competitor due to meeting any of the aforementioned parameters.
Advanced competitors vehicles must comply with all stock install rules for all equipment installed before the B-Pillar, but may have equipment behind the B-Pillars mounted outside the boot area

There is one class in the “Advanced” Division:

This is an open class with no cone area restrictions

Competitors competing in the “Advanced” Division must meet the following criteria:

The vehicle must have OEM style glass in all windows.
The vehicles windscreen & front door windows cannot be obstructed or modified. (Having a cracked windscreen may result in disqualification.)
Windows that rolled up & down when the vehicle was manufactured must remain operational.
Speaker upgrades can be made in front of the “B” pillar only for sound quality purposes.
The vehicle must have its factory dashboard intact & not modified, other than possibly with small speaker builds (i.e. surface mounted tweeters.)
Factory style door panels must remain intact with the possible exception of a partial door build-out to house an operational driver that is smaller in diameter than the woofers being used to generate SPL.
The only acceptable kick-panel modification is the addition of partial build outs to house functional drivers for the purpose of creating a better sound stage & imaging.
Competitors in the Advanced Division are allowed to use multiple amplifiers for each physically installed woofer voice coil.
Amplifiers mounted forward of the plane of the B-pillar may only be used to power front components.
Factory fitted headliner must be unmodified, remain intact & in its original location.
Factory floorboard must remain intact, not reinforced or raised & must be covered in factory or OEM style carpeting
Vehicle must have two factory, OEM style or approved aftermarket car seats mounted in the passenger compartment forward of the B-pillars. (Exception: One seat may be used if it is a full-length bench style seat.)
Seat(s) can be adjusted as per the rules but cannot be removed during testing.
Both front seat belts must be in the vehicle, functional & mounted to the original factory mounts.
Equipment & battery racks should only be of sufficient size to contain the equipment mounted therein. If, in the Head Judges opinion, the use of any materials is to solely fill up unused/unwanted space, then this will result in the vehicle being moved into “Ultimate class”
The enclosure must be mounted behind the plane of the B-pillar, but the rear compartment cannot be totally sealed from the front compartment.
SUV’s & Vans must have the enclosure behind the B-pillar but the rear compartment cannot be totally sealed from the front compartment.
If an after-market or modified centre console is mounted in the vehicle it must be functional. “Functional”, in the case of a centre console means that it can either provide storage space or house electronics such as equalisers, switches, or video equipment. It cannot house any speakers. If, in the opinion of the Head Judge, the console has been installed for the purpose of taking up passenger area space, the competitor will be directed to compete in the “Ultimate” Division. (Suggestion: Outside dimensions of approximately 24” x 12” x 12” should avoid any possible conflicts.)
In the Advanced Division the maximum system voltage allowed is 14.6 Volts with the engine running.
Nothing may interfere with the correct placement of the microphone placement template. (See template placement instructions & drawing.)

“Ultimate” Division

INTENT:

The intent of the “Ultimate” Division is to provide a playing field for those competitors that compete with vehicles whose interiors have been altered beyond the criteria found in the “Advanced” Division definitions. The “Ultimate” Division also provides a format where Pro’s & Consumers can compete against each other. Vehicles or competitors that meet any of the following criteria will compete in the “Ultimate” Division.

A competitor will be assigned to the “Ultimate” Division if they meet at least one (1) of the following qualifications. Items 1, 2, & 3 below shall also serve to define a “Pro” competitor.

The competitor derives any income, however small, from being directly involved in the selling, installation, manufacturing, designing, testing or engineering of car sound electronics, speakers, speaker enclosures or accessories. They derive any income from being paid by the publisher of any car sound related material.
Has either received, or expects to receive, financial support or other compensation for promotional consideration from any car sound industry related person or company for participation in any event or promotion.
By their own choice.
Any participant who is unable to qualify as a “Stock” or “Advanced” Division competitor due to meeting any of the aforementioned parameters.

There is one class in the “Ultimate” Division:

This is an open class with no cone area restrictions

Competitors will compete in the “Ultimate” Division if any of the following criteria are met:

Any vehicle with its floorboard raised above the original factory doorjamb.
Any vehicle in which the metal framing of the door jamb area has been altered from the original factory specifications.
Any vehicle with one or more door panel builds that extend more than 4 inches from the original door panel.
Competitors in the Ultimate Division are allowed to use multiple amplifiers for each physically installed woofer voice coil.
Any vehicle competing with internally modified amplifiers.
Any vehicle with a modified charging system. In Ultimate Division the maximum system voltage allowed is 16 Volts with the engine running.
The factory windscreen & side window glass may be replaced with any fully transparent material. The transparent material replacing the windscreen must retain no less than 70% of the original factory area of unobstructed visibility
A console which extends above the top of the dashboard.
The passenger compartment must have enough space to be able to comfortably accommodate two (2) average build adult passengers.
A barrier or partition may not be used to compartmentalize the passenger compartment. An average sized adult should be able to transfer from one side of the vehicle to the other.
Nothing may interfere with the correct placement of the microphone placement template. (See template placement instructions & drawing.)

Official Microphone placement Guidelines

The Judge(s) will ensure that the microphone height & orientation is absolutely consistent from vehicle to vehicle.

The microphone will be placed according to the following:

The microphone capsule will face forwards toward the front of the vehicle at all times.
The suction cup microphone holder should be used to position the microphone properly.
The microphone capsule will be placed:
- Twelve (12) inches from the edge of the glass at the passenger side A-pillar.
- Four (4) inches from the bottom edge of the windscreen.
- One (1) inch from the windshield on the inside
- As close to horizontal as possible.

Use the following microphone placement template & place the capsule (tip) of the microphone in the hole so that the tip is flush with the back side of the template.

Positioning instructions for the 190d transducer shall be the same as those for the microphone; except that it will be affixed to the screen using the manufacturers supplied sucker attachment.

The Measurement Procedure

Upon entering the judging area, the Judge(s) will confirm that the hand brake is set & then place the microphone in the vehicle under test according to the official guidelines.
Once placed in the proper position, the contestant will have the opportunity to verify the position of the microphone. The contestant is not allowed to touch the microphone at any time. Violation may result in disqualification.
The contestant will then have one (1) minute to set their system for the SPL measurement.
Failure to be ready to compete following the allotted one (1) minute will result in a score of zero (0) for that round.
After the set up time & on the Judge’s command, the contestant will have thirty (30) seconds to perform the SPL measurement.
After the measurement is completed, the contestant will have two (2) minutes to exit the judging area.

SQ. INCH CONVERSION CHART

Optional for SPL

It can be decided by the Event Director before the competition starts, as an option, to have a pre-qualification and a Knockout system.

The Qualification:

The best four/eight competitors of each class are qualified for the Knockout stage, as decided on the outcome of two open rounds.

The measurement procedure is the same as the normal competition rounds. A second measurement is not allowed.

The Quarter Final:

The first after the qualification rounds has to compete against the last, the second against the seventh, the third against the sixth, and the fourth against the fifth place qualifiers.

The Semi Final:

In the Semi Finals the first will compete against the fourth, and the second against the third.

The Final:

The final follows with the two winners of the Semi final being placed against each other.

The following general procedures and rules must be adhered to during the SPL judging:

All audio equipment used in the construction of a competition vehicle should be available to the public through normal retail channels.
All vehicles must pass a basic install safety & security check, as per the standard EMMA basic install rules.
The program material must be reproduced using loudspeakers driven by an amplifier(s) playing the chosen source material.
The use of compressed air, explosive devices or gases, etc. is not allowed.
The competitor must supply their own source material.
Stock competitors will be limited to using any commercially available recording.
Advanced/Ultimate competitors will have free choice, however all source material must be on some form of pre-recorded media i.e. CD/DVD/Hard Drive/Memory stick, etc. Tone generators of any sort are not allowed.
The Judges will not adjust any volume control, track selection control or head unit switch. The volume is only to be controlled by the owner or presenter of the competition vehicle.
If the competition is held outside it is permissible to have the engine running during the measurement process. If inside a building, then no vehicle will be allowed to run the engine during the measurement process.
If the vehicles engine is running during testing, then the parking brake must be applied, the maximum engine speed must not exceed 2000 RPM, & the Judges must determine that there is no potential danger to the Judges, spectators or contestants. Any vehicle that does not have a fully functional emergency brake may not compete with its engine running! It is highly recommended that wheel chocks be used in addition to setting the parking brake. Failure to comply with this rule will result in the run being terminated and no score recorded. Multiple infringements may result in disqualification from the event.
In the interest of safety it is recommended that the competitor uses a remote control device for competition in all Classes & that all competitors testing from outside the vehicle also have an engine kill device accessible from outside the vehicle.
No additional power supplies are allowed to be connected during the measurement process.
Voltage measurement will only be taken with an approved, Organisers supplied, meter and systems may be inspected for this at any point during the event.
The Head Judge has the right to require any competitor to “tear down” their system for the purpose of verifying rules/system compliance. Any refusal to submit may result in their disqualification from the event.
Where possible, the Vehicles must be shown to the public after the measurement is finished. The organisers will endeavour to provide an area for presentation. In that case the vehicles must be presented to the public for a minimum of five (5) Minutes per run.
Vehicles with more than two midrange/woofers speakers per side up front must compete in the next higher competition class. The mid woofer(s) must be smaller than 20cm (8”).
A competitor may not add or remove speakers to a system during the course of a competition. Like for like replacement of damaged equipment is permitted between runs.
For all classes all subwoofers must be mounted behind the plane of the original B-Pillar.
Opening the door after the test starts will result in the competitor receiving a score of zero (0) for that attempt.
The competitor is responsible for his/her equipment and EMMA or the event organisers take over no responsibility or guarantees in case of any damage to the sound system or the vehicle.
It is the competitor’s decision if he/she will sit inside the vehicle during the judging process. EMMA is not responsible for damages of the health of the contestant but strongly recommends for them to be careful!!!
If the competitor does elect to sit inside the vehicle during competition, suitable hearing protection must be worn. Failure to comply with this rule at any time will result in the run being terminated and no score recorded. Multiple infringements may result in disqualification from the event.
Only officially registered vehicles are allowed to compete and they must be able to be driven inside and outside the judging area by using their own engine power.
A front system must be installed as per the SQ rules of the official EMMA Rulebook. If the front system is installed in another or even a dangerous way the vehicle has to compete in Ultimate category.
In the Stock classes it is not permissible to remove the signal for the front midrange and tweeter section of the audio system. However, the competitor may lower the volume of these speakers. If it is deemed that there is no audible sound coming from the front midrange or tweeter during the measurement process, the run will be terminated and no score recorded. Multiple infringements may result in disqualification from the event.
In Advanced/Ultimate classes a front end system capable of playing music must be installed, but may be disconnected during the measurement process. The front end system must, however, be in use during the public demonstration period.
All components of the audio-system must be installed within the vehicle. Trailers, roof boxes, etc. are not allowed.
The participating vehicles should be stock or moderately damped (as normal for SQ-vehicles, approx. 3mm). If polyurethane-foam, concrete, etc. is used, the vehicle must compete in the Ultimate Division.
Additional batteries may be installed in the engine or the boot compartment. If they are installed in the passenger compartment, the vehicle must compete in the Advanced/Ultimate classes. All batteries must be securely mounted.
The source unit must be permanently installed in the vehicle, as per the SQ rules; otherwise the competitor must compete in the Advanced/Ultimate classes.
No powered transducers, vents, or ports may be located within twenty four (24) inches of the microphone tip/SPL sensor during the test.
All SPL Measurements shall be taken with the Audio Control Analyser and the according high SPL Microphone or SPL Sensor (or a similar approved device).
Competitors are permitted to move their front seats to any desired position before the Judge positions the microphone. The seatbacks are not allowed to be tilted forwards of vertical.
The microphone Tip placement will be on the front windscreen, using the Organisers approved jig (with the microphone tip 12 inches in from the left-hand edge of the windscreen glass, 4 inches above the bottom edge of the glass, and 1 inch from the glass). If the 190dB sensor is used, the position will be the same, 12 inches in, 4 inches up & affixed to the glass using the manufacturers supplied sucker attachment.
At the competitor’s discretion, the SQ RTA microphone position may be used as follows. The microphone will be placed by an authorised Judge at least 30 centimetres from the front windshield and the competitor is not allowed to touch it in any way.
The cable of the microphone must be routed through the original door opening by the Judge. No special devices are allowed. Nothing may be used other than the official measuring equipment, cables etc.

As a general rule of thumb, with regard to specific items, if it is not written and/or addressed specifically in these rules, it will be judged illegal until otherwise specified by the Rules Committee and/or Head Judge Council.

Protest & Teardowns

A contestant can challenge the fair play of another competitor.

This may include incorrect or inappropriate classification, suspected cheating or falsifying of competitor information.

This protest can result in a teardown or re-test of the protested competitor’s vehicle.

Protests are initiated by the following procedure:

Teardowns and protests must be lodged before the prize giving ceremony begins. Re-testing may be done under the direction of the Head Judge after the protested vehicle’s judging has been completed but before winners are announced.
This challenge can only take place on the day of the event and at the event site.
Only a competitor in the same class, registered in that event, may file a protest or request a teardown.
Any non-competitor or Team Leader who protests or attempts to protest on behalf of a registered competitor can, at the Head Judge’s or Event Director’s discretion, have him/herself and the competitor (Team) he/she represents removed from the contest.
The Head Judge will investigate the protest with the employed Judge team.

Should a contestant wish to challenge another contestants vehicle then an official written protest must be lodged with the Head Judge and must be accompanied with a fee of €100/£100 in cash.

The written protest should briefly describe what is being protested.

Should a violation be discovered in the contested vehicle the cash fee will be returned to the challenger; and appropriate measures will be taken regarding the violation.

However, should no violation be discovered, the protesting contestant will loose the fee.

In this case the fee will be equally split between the organisers & the challenged competitor

On each event the Head Judge or the Event Director are the highest court. For anything that is not described in these rules please refer to the Head Judge/Event Director.