New SPL Classifications – TermLab Magnum

MECA Manufacturers and Supporters

MECA’s Sound Pressure League will be using the TermLab Magnum system for 2016 as our Official SPL Meter. It monitors the actual, live, RMS wattage being applied to the speakers via an Amperage Clamp and a set of Voltage Probes and does the calculations simultaneously along with the score to place the competitor in the correct class.

The Pressure Class formula that is exclusive to MECA SPL contests, has been modified to plug in the actual wattage plus cone surface area to determine class assignment. Previously, the (fusing X 10) determined power in the formula. This new method of calculating true power will make the MECA SPL classes the most fair in MECA’s 17 year history.

The lowest type classes, determined by complexity of design and the “potential to make bass” (Pressure Class Formula #) will normally spec to a real-world audio system, with 2 12″ woofers and approximately 520 watts. 

Divisions have been adjusted with 2 Amateur Street classes being removed, and, with Street having 4 classes with no unlimited class. A new Division, Modified Street or MS, will have 3 classes, and is for the more competitive vehicles with no back seats like 2-seat hatchbacks, and extended cab trucks, and will have a no-wall build allowance, to the B-pillars and as high as the bottom of the side windows. MS3 will be unlimited. Any class that is unlimited will not be clamped, like MS3, M5, X, and DB5.

Some flexibility will be allowed for 2016 for points. 40 points will still be the requirement for Finals invitation. At least half of those points must be in the declared class for Finals. This is for 2016 only and done to make sure members make it to Finals, given new system and some of the uncertainty that might develop.

These are the classes. Subtract the cone surface area from the top bracket # to get allowed wattage to stay in the class. For example, for Street 1, with 2 12″ woofers being 226 square inches, the maximum wattage allowed is 524 watts.

T1 0-4000
T2 4001-7500
7501+ competes in MS3

S1 0-750
S2 751-2000
S3 2001-4000
S4 4001-7500
7501+ competes in MS3

Modified Street
MS1 0-4000
MS2 4001-7500
MS3 7501+

M1 0-1000
M2 1001-2000
M3 2001-4000
M4 4001-7500
M5 7501+

Park & Pound
DB1 0-1000
DB2 1001-2000
DB3 2001-4000
DB4 4001-7500
DB5 7501+

We will have the 2016 Rule Book posted soon. This gives everyone a real heads-up about what is coming up. There will be issues we have not foreseen, and we will deal with them in a fair and sensible manner.

Thanks to our Rules & Ethics Members who have been working through this, especially SPL Co-ordinator Rick Washabaugh, and Joe Ault and Bud Ballinger.

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