Quantum Audio QP124 Product Specifications, Calculating Enclosures, Calculating External Volume

PRODUCT SPECIFICATIONS

Free Air Resonance.	(FS)	30
Total Q of driver @ FS including all resistances.	(Qts)	.45
Q of driver @ FS including non electrical resistance only.	(Qms)	5.75
Q of driver @ FS including electrical resistance only.	(Qes)	.49
The driver's compliance expressed as an equivalent volume
of air (Cubic Ft.).	(Vas)	2.0
The driver's linear displacement (inches).	(Xmax)	.31
The DC resistance of the driver's voice coil (Ohms).	(Re)	3.2
Thermal power rating of driver (R.M.S./Peak).	(Pe) 400 / 800
The driver's voice coil inductance (millihenries).	(Le)	2.64
The driver’s sensitivity (dB).	(Sens)	89

CALCULATING ENCLOSURES

It is difficult to give exact box dimensions that are universal for all cars and trucks. It is for this reason that you must be able to calculate the space in which you have available in order to achieve the proper air volume required.

It is recommended to build your enclosure from 3/4" thick MDF (medium density fiberboard). Make sure the enclosure is sealed airtight.

Calculating External Volume

1.) To calculate box volume, measure the outside Width x Height x Depth of the enclosure. Example 12" x 14" x 9" = 1512".

2.) Next you must convert cubic inches into cubic feet. To do this, you must divide the cubic inch total by 1728". Example 1512 ÷ 1728 = .875 Cubic feet

Calculating Internal Volume

1.) To calculate the internal (net) volume of the above box you must first multiply the thickness of the wood you are using by Two (2). Example 3/4" x 2 = 1.5".

2.) Next subtract 1.5 from each of the outside measurements of the box.

Width	Height	Depth
12-1.5=10.5	14 -1.5 = 12.5	9 -1.5 = 7.5

3.) Multiply the new totals (H x W x D) Example: 10.5 x 12.5 x 7.5 = 984.375

4.) Next you must convert cubic inches into cubic feet. To do this, you must divide the cubic inch total by 1728" Example 984.375 ÷ 1728 = .5696 cubic feet.

QP124