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[Mega Heavy Bass]

SPL Testing Types & Categories:
((((Propper Droppers)))) - Where all SPL measurements are taken from the inside of the car.
A series of tests are done to see how well the system performs at playing certain low bass frequencies as loud as possible.

The test consists of:
1: How loud your system can possibly play - Peak SPL.
2: Playing the following set tones. 40Hz - 33Hz   -25Hz - 20Hz. - This shows you how well your system performs at playing low bass.

SPL CATEGORIES:
I have split the system categories into the following types.

BOOT BOOMERS:-Currently Split into 4x Groups:




1: The system has to be within the boot area of the car as in, it has to be in the boot area behind the rear seats.
2: Boot Boomers height limit is limited to 2" above the top most level of the rear seats.

Any part of the box or bass system which exceeds this limit will be put into BOOT BOOMERS EXTREME.

This includes:

1: Any part of the subwoofers including the surround.
2: Ports
3: Scooped canopys
4: Bass Amplifiers

3: Other amps or speakers, as long as they are not for the bass can still be fitted above this level. 



BOOT BOOMERS EXTREME category allows for any type of boot system as long as it is behind the rear most seats.
1:Full walled boots are allowed - boxes that go right up to the roof are allowed, anything really.

2: Any type of internal build, battery trays and vehicle modification is allowed in this class except external power supplies.

NO-WALL -  No groups - Just one class

Wot no back seats?

No-Walled systems that are a lot larger than normal and usually take up both the rear seat areas and boot areas of the vehicle.

1: The box or subwoofer enclosure itself must not be higher than the center point of the side windows. Any system that has a subwoofer enclosure that is above this level will be put into WALLED category.
The systems amps and subs when mounted mags out, can extend beyond the height limit in this category.

2: Any type of internal build, battery trays and vehicle modification are allowed in this class except external power supplies.

WALLED: Typically the loudest type of vehicle sound systems around.


1:The rear off the car is normally filled with a huge wall of subwoofers which fill up the whole vehicle starting from just behind the front seats, filling the space from top to bottom of the vehicle and also extending into the boot area.

2: Any type of internal build, battery trays and vehicle modification are allowed in this class except external power supplies.

SPL Leagues:
Your position in the SPL leagues is worked out as follows:
Example:
Peak = 152.7dB @ 33Hz
40Hz = 150.4dB
33Hz = 152.7dB
25Hz = 151.6dB
20Hz = 150.7dB

All these scores are added together & then divided by "five" - Five being the number of different scores that have been achieved.
By doing this we get the TOTAL AVERAGE score achieved during the SPL testing session. Which in this case would be 151.6dB

SPL LEAGUES:
You`ll find each seasons / year SPL results and leagues on the forum pages.
They will consist of the TOP 10 Loudest Cars in each category, for that season / year and then the other systems that came after them.

OFFICIAL SPL READINGS:
1: To get official SPL League Scores the scores must be witnessed by myself.
2: All other scores will be classed as Bass Bandit scores.

[Mega Heavy Bass]

The SPL Measuring Equipment:
I use an industry standard SPL sensor as used by the worlds most popular SPL organisations.
Known as the Term Lab Sensor - It is currently the most accurate & reliable way of testing for SPL.




SPL Readings:  Must be taken using a TermLab sensor. The Sensor must also be placed in roughly the same position for each car.

SPL Sensor  Positions etc:
We are attempting to get an SPL reading which is as reasonably accurate as possible, as if you were listening to it. To that end we take the SPL readings from roughly where your head would be when sitting in the vehicle.

In -Car:
1: The sensor is positioned approx where the passengers or drivers head would normally be. This means that the Sensor is attached to a HEAD REST, which represents the person in a seated position.

1a: The sensor must always be facing towards the front windscreen and fitted in either the passenger or drivers Head Rest.

1b: Once the SPL Passenger or Drivers sensor position has been chosen it has to stay in that position for the whole SPL test.

1c:The only time the SPL sensor position can be changed is when the whole testing procedure has been completed and the participant wants it to be moved to the opposite position and another test carried out to see if any of their previous scores have increased.

This is allowed due to the design of some systems (Mainly walled systems)where the Port is to one side of the vehicle making certain frequencies louder at the driver and passenger positions.


2: Seat positioning is important as the drivers seat should remain in its normal daily driving position.
The passenger seat should mirror as much as possble, the drivers seat position.

2a:On no account should the seats be pushed all the way forwards or the seat backs be positioned in such a way to increase SPL.

This is what I normally do when testing.

(((Propper Droppers))) SPL Testing Part 0

(((Propper Droppers))) SPL Testing

Thanks.

[Mega Heavy Bass]

GENERAL RULES:
1:  Hearing Protection is provided & is advised to be worn during the SPL testing process.
2:  Disclaimer for damage against equipment & personal injury due to exposure of high SPL levels MUST be signed before any test is to be carried out.
3:  Engines can be left running / idling - The accelerator is allowed to be pressed if the participant feels that this may help to increase his / her score, whilst playing a test tone.
4:  All SPL categories can have as much bass amps - speakers etc that will fit into the available space of the category that their system falls into.
4a: Batteries can be positioned anywhere throughout the vehicle - Amplifiers that are not used for powering subwoofers can also be positioned anywhere throughout the vehicle.
5:  All categories can have as much sound deadening / strengthening mods as the owner wishes.
6:  No restrictions on any type of playback equipment - Cd Players , DVD Players, I-POD, USB, SD, Hard Drives etc can all be used.
7:  There are normally no restrictions on the amount of time it takes to carry out an SPL test.
7a:However if the tests are being carried out in an open day / event where prizes or trophies are being given out or there are many people waiting to be tested (Over 15), then there is an advised 30sec time limit for each frequency attempt.
8: The testing is normally carried out by using an officially available test CD or a digital form of test CD.
8a: However if the participant feels that their system can play certain frequencies louder by actually playing music instead of the test tones that are provided on a Test CD etc then they are free to try using that method.
9: The use of external battery supplies and power sources which are outside the vehicle are currently prohibited.
9a: Battery trays are allowed however they must be positioned within the inside of the vehicle - The only exception is Rule 9b.
9b: Build downs to stored batteries from below the floor pan are allowed provided the tray has been constructed in a safe manner and also completely seals the batteries from the outside of the vehicle - rendering the battery tray as part of the internal structure of the vehicle.
10: More than one person can be inside the vehicle whilst testing.
11: The SPL sensor can be placed on either the passenger or drivers head rests.
11a: The SPL sensor, once positioned on passengers or drivers head rest must remain in that position throughout the SPL testing process.
11b: You cannot swap the positions mid testing but you can re-test with the sensor on a different side.
Any higher scores can be taken as the participants systems score.
This benefits system that are built for other SPL formats as the port is usually to one side of the vehicle.

DOORS and WINDOWS - BODY PANELS:

1:  Any combination of doors, windows or sunroofs, even the boot, can be opened or closed to try & and achieve a higher SPL score.
3:  Doors, windows, sunroofs, roofs and body panels etc can be pushed against to try & achieve a higher score.

ISO SYSTEMS:
This is where two subs are mounted in such a way as to provide extra motor strength but still using the same cone area as a normal subwoofer.
Clam shell method is the most popular method of mounting in this way.
Any system which participates using this type of set up will have each clamshelled pair of subwoofers classed as one Subwoofer  


EXTRA STUFF:

PORT BLOCKING - MULTIPLE USE PORTS:
1: The standard SPL test does not allow for any kind of port or box alterations in which to increase specific frequencies.

The idea of this test is to see just how well your normal, Sound system performs at playing low bass.

UPGRADING OF SCORES:

1: If you manage to beat your systems previous best score at any frequency, with EXACTLY the same BASS BOX SYSTEM - PORT CONFIGURATION and MAKE of SUBWOOFER set up that you used before, then that score will be upgraded and your overall score updated to suit.

[Mega Heavy Bass]

SPL TESTING RESTRICTIONS and Costs:

1: The current SPL ((((Propper Droppers)))) SPL season starts and finishes at the same time as the www.pure-carma events. (Usually March till September).
Any Offcial SPL scores that have been taken before the 1st event will not be put on the Leagues until the 1st event has been boomed out.

1a: (((Ground Pounders))) runs throughout the year whenever it is possible to do so.

2: Official League Scores can only be registered if the FULL SPL testing process (All 4 frequencies & Peak) has been carried out and that I, Marcos Barnes A.K.A. Mega Heavy Bass have actually witnessed the tests taking place.

2a: No other SPL Judge or member of staff will be able to post up their scores or any other vehicles they may have tested as Official League Scores unless the whole SPL testing process has been carried out and I`ve witnessed the tests taking place.

2b: If by any chance I cannot be at a pre arranged event that I have organised myself, I will give another SPL Judge the authority to act on my behalf.

3: SPL Judges have the authority to carry out their own SPL tests using the ((((Propper Droppers)))) SPL format at cruises or meets in their areas taking into account the costs explained below.

NOTE: SPL testing is not free.

FEES ETC:
1:  Normal SPL testing at large events or open days in which trophies or prizes are given out will carry a charge of £10.00 for the testing session.
1a:If the participant feels that they can get louder and wants to try again whilst the event is running...  They can if circumstances allow, without any further charge, and at the testers discretion, have another attempt.

SPL testing at Cruises or meets can be done in two ways.
This is more aimed at the SPL Judges who test independantly from myself.
Appointed SPL Judges will receive details of payable subscription fees towards Streetbassers, which is a small percentage of the fee deducted from their SPL tests.

Current SPL Judges who are Authorised to test and give out SPL certificates are:

Mugwhy
Matty
Zangief!!
T16 AGH
Richard VXincar

If any other SPL Judge has access to a TermLab and would like to be involved then please PM me.
 
Mini SPL Test.
PEAK (The loudest possible bass not your system can play) and 20Hz.
A charge of £2.50 is required before the test is carried out - A specific Mini - SPL Certificate will also be given out.

NOTE: Mini SPL scores are not classed as full official ((((Propper Droppers)))) scores and will not go towards your OFFICIAL ((((Propper Droppers)))) SPL League Scores.

Full SPL test.PEAK - 40Hz - 33Hz -25Hz -20Hz.
A charge of £5.00 is required before the test is carried out - An SPL certificate will also be given out.

NOTE: Full SPL scores will only be classed as official if I have witnessed them.
To get an official League scores you have to attend one of our sound offs or meets where I am in attendance.

NOTE:  ALL tested SPL scores must be posted up on the (((BASS BANDITS))) section, unless I have witnessed them.


SPL Certificates:
These should be gven out to everyone that has paid the full price to participate in a Full or Mini (((PD))) test.
If no SPL certificates are available then a minimum of £1 is charged for the mini test and £2.50 for the full test.  
The results are still posted up as usual.