Quantum QC12S4 Service manual

QC12S4 - 12” Subwoofer
Installation Instructions / Owner's Manual
QUANTUM AUDIO
www.quantumaudio.net
Tel: [phone] Fax: [phone]

1
WARNING!
Exposure to high sound pressure levels can cause hearing loss or
damage. Listening to your system at loud levels while driving, will
impair your ability to hear traffic sounds and emergency vehicles.
Use common sense when listening to your system.
When installing your subwoofer enclosure in the vehicle, securely
fasten it to the frame or floorpan. If the enclosure is not secured
properly, there is danger of it becoming a projectile in a collision.
Due to continuing product improvement, specifications and design are subject to change without notice.
INTRODUCTION
Congratulations on your purchase of an Quantum Audio state-of-the-art subwoofer
component. Your selection of an Quantum Audio car audio product indicates a true
appreciation of fine musical reproduction. Whether adding to an existing system or
including a Quantum Audio subwoofer in a new system, you are certain to notice
immediate performance benefits.
KEEP YOUR SALES RECEIPT
Take this time to attach your sales receipt to the manual and put in a safe place. In
case of any unforeseen reason this product may need warranty service, your receipt
will be necessary to establish purchase date.
RECOMMENDATION
A speaker's performance is only as good as it's enclosure. Proper installation,
enclosure size and crossover frequency will maximize the overall performance of
the subwoofer. To properly design and build an enclosure, knowledge of
woodworking as well as the proper tools are required. We highly recommend that
you have your enclosure built by an authorized Quantum Audio retailer. However, if
you decide to install it yourself, we have included the parameters of each driver and
recommended enclosure sizes. If after reviewing the enclosed information you have
any additional questions, please feel free to contact our technical dept.

2QC12S4
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.
PRODUCT SPECIFICATIONS
Free Air Resonance. (FS) 25
Total Q of driver @ FS including all resistances. (Qts) .53
Q of driver @ FS including non electrical resistance only. (Qms) 7.66
Q of driver @ FS including electrical resistance only. (Qes) .56
The driver's compliance expressed as an equivalent volume
of air (Cubic Ft.). (Vas) 1.67
The driver's linear displacement (inches). (Xmax) .55
The DC resistance of the driver's voice coil (Ohms). (Re) 3.4
Thermal power rating of driver (R.M.S./Peak). (Pe) 750/1500
The driver's voice coil inductance (millihenries). (Le) 3.2
The driver’s sensitivity (dB). (Sens) 87

Ported Enclosure
Box Volume *2.0 Cu Ft.
Port Frequency (Fb) 35 Hz
Port Diameter 4 Inches
Port Length 11.97 Inches
FrequencyFrequency
QC12S4 Amplitude Response (dB/Hz)QC12S4 Amplitude Response (dB/Hz) Sealed EnclosureSealed Enclosure
5 Hz5 Hz 1010 5050 100100 500500 10001000
00
dBdB
66
1212
-6-6
-12-12
-18-18
-24-24
F3 = 35F3 = 35
RECOMMENDED ENCLOSURES
Please Note: Our suggested box volumes are given as internal air requirements
Sealed Enclosure
Box Volume * 1.0 Cu Ft.
* Box is given as internal air volume including driver
displacement.
QC12S4 AMPLITUDE RESPONSE (DB/HZ)QC12S4 AMPLITUDE RESPONSE (DB/HZ) Ported EnclosurePorted Enclosure
5050 100100 500500 100010005 Hz5 Hz 1010
00
dBdB
66
1212
-6-6
-12-12
-18-18
-24-24
F3 = 34F3 = 34
Manual By
www.extremeconcepts.com
QC12S4 REV 1.16.05