VXW 300 - Pregnant BLAUPUNKT - Free user manual and instructions

Product type	Car subwoofer
Brand	BLAUPUNKT
Model	VXW 300
Speaker diameter	30 cm (12 inches)
Nominal power (RMS)	300 W
Maximum power (peak)	600 W
Impedance	Dual voice coil 4 ohms (configurable to 2 or 8 ohms)
Sensitivity	90 dB (1 W/1 m)
Frequency response	20 Hz - 500 Hz
Diaphragm material	Wrinkled mica polypropylene
Magnet type	Strontium ferrite
Suspension	Ultra-linear long throw
Voice coil	4 layers on Kapton polyamide body, supports up to 225°C
Pole piece	Ventilated at the rear for cooling
Cone excursion	6 to 9 mm
Recommended use	Sealed enclosure, bass-reflex or bandpass
Approximate weight	5 kg
Dimensions (diameter x depth)	30 cm x 15 cm
Power supply	Via external amplifier (12 V)
Maintenance	Clean the exterior with a soft, dry cloth. Check connections periodically.
Safety	Disconnect the battery during installation. Do not mount on flexible surfaces.
Warranty	2 years
Included accessories	Sealing gasket, mounting screws, user manual

Frequently Asked Questions - VXW 300 BLAUPUNKT

How to install the VXW 300 subwoofer in my car?

Before any installation, disconnect the negative battery terminal. Mount the subwoofer in a suitable enclosure or on an infinite baffle (e.g., rear shelf). Make sure the enclosure is airtight and stable. Use cables with a minimum cross-section of 4 mm² and connect the amplifier to the subwoofer with short connections.

What type of enclosure should I use for the VXW 300?

The VXW 300 can be used in sealed, bass-reflex or bandpass enclosures. Sealed enclosures offer excellent impulse response and high power handling. Bass-reflex enclosures extend the low-frequency range. Bandpass enclosures are more complex but offer high efficiency over a narrow band.

How do I calculate the optimal enclosure volume for the VXW 300?

Use the Thiele-Small parameters (Fs, Qts, Vas) provided in the manual. Basic formulas include: sealed enclosure volume = Vas / (Qtc^2 - 1) with Qtc typically 0.7. For bass-reflex, refer to charts. Simulation programs are available on the Velocity website.

What amplifier power is recommended for the VXW 300?

The subwoofer RMS power is 300 W. Use an amplifier delivering between 300 and 600 W RMS at the load impedance (2, 4 or 8 ohms depending on the dual voice coil wiring). Avoid exceeding maximum power to prevent voice coil damage.

How to wire a dual voice coil subwoofer like the VXW 300?

The VXW 300 has two 4 ohm voice coils. You can wire them in series (8 ohms), parallel (2 ohms) or use a single coil (4 ohms). Ensure the amplifier supports the resulting impedance. Respect polarity (+/-) for proper phase alignment.

What low-pass filter settings should I use?

Set the amplifier's low-pass filter between 80 and 120 Hz. For integration with satellite speakers, start around 80 Hz. Use an active crossover (built into Velocity amplifiers) for better control.

How to seal the subwoofer enclosure?

Use foam gaskets or silicone for all joints. Screw and glue the panels. Check airtightness by gently pressing the diaphragm: it should return slowly. Air gaps must be filled with sealing material.

What material is recommended for building the enclosure?

Use MDF or high-quality plywood (birch) 19 to 25 mm thick. Avoid complex shapes. Add bracing for large enclosures to prevent vibrations.

How to reduce enclosure vibrations and resonances?

Cover the inside of the enclosure 50% with acoustic damping material (sheep wool, polyester felt 5 to 10 cm). Stick sound-deadening mats on the walls. This reduces resonances and increases effective volume by 10 to 20%.

What to do if the subwoofer produces no sound?

Check cable connections, polarity, and amplifier power. Test with another source. Ensure total impedance is compatible with the amplifier. If the problem persists, consult a professional installer.

USER MANUAL VXW 300 BLAUPUNKT

VXW 250, VXW 300, VXW 380

Thanks for choosing Velocity!

Congratulations on your purchase of your new Velocity product! We have invested tremendous effort in the de-sign process of the new Velocity subwoofer series, in order to achieve superior musical performance.

For maximum performance and reliability we highly recommend that your new Velocity subwoofer be installed by an authorised Velocity dealer. By using our Velocity line component speakers and amplifiers you can be as-sured of making the best out of your high-quality audio hi-fi system without spoiling the sound by using com-ponents of inferior quality.

For additional information on the Velocity Product Line (technical data, user notes and soon also a simulation programme for subwoofer housings) visit our Internet site at: http://www.velocity.de.

NEW COMPONENT FEATURES

High Power handling

Incredibly flexible installation: The new Velocity subwooers perform well in sealed, vented and bandpass boxes.

Due to the low resonance values, the new Velocity subwooers also work well in infinite baffle installations in which the woofer is mounted on the rear deck, using the trunk of the car for its acoustical enclosure.

New ultra-linear long-throw suspension.

Corrugated mica polypropylene design yields tremendous rigidity.

Additional loudness is achieved through longer cone travel, so we designed the Velocity subwoofer with 6 to 9 mm peak-to-peak excursion.

The new reinforced spider renders spider tears a thing of the past.

Butyl rubber surrounds offer linear cone movement without compression or the risk of tearing from over-excursion even for longer cone travel.

New strontium ceramic ferrite magnets yield smaller magnet sizes without reduced magnet strength but retain their magnet power far beyond the expected life of the woofer.

Four layers of high-temperature wire on DuPont Kapton Polyamide voice coil bobbins allow for voice coil temperatures exceeding nearly 225 degrees Celsius without damage.

Rear vented T-yokes allow fresh air to move in from behind the woofer to cool the voice coil.

Safety precautions

Before starting to mount your speakers, please read carefully the instructions on installation and connection.

Disconnect the negative terminal of the battery before carrying out installation and connection work. Observe the vehicle manufacturer's safety instructions (regarding airbags, alarm systems, trip computers, vehicle immobilisers).

When drilling holes, take care to avoid damage to vehicle components (battery, cables, fuse boxes). Do not mount the subwoofer onto flexible rear decks (hatchback vehicles) or anywhere where they may fall for-ward.

DUAL VOICE COIL ADVANTAGES

The dual voice coil woofer is actually quite old in the home audio industry but still relatively new to the car audio world. The largest advantage of the DVC woofer is in the flexibility in installation. In order to raise the sound pressure level (loudness) in a car, you can either add more speakers or add more amplifier power to drive a single speaker. Many cars cannot fit two subwoofer and their necessary enclosure volumes but can easily fit large power amplifiers and a single woofer. Simply speaking, the DVC woofer allows you to make up for speaker deficiencies with additional amplifier power.

SUBWOOFER ENCLOSURE TYPES

Sound is created by the movement of the woofer cone back and forth. If a woofer cone moves forward creating a positive pressure wave, this same motion creates a negative pressure at the back of the woofer. If these two waves combine due to the lack of a wall separating the front of the speaker sound from the back, the output from the woofer is effectively cancelled thus substantially reducing the bass output of the speaker. This wall is absolutely necessary and is referred to as an acoustical baffle. It can be accomplished using a box of some kind or simply the rear package shelf of an automobile to isolate the front and back waves of the speaker.

THIELE-SMALL PARAMETERS

Every woofer has its own electromechanical characteristics which are called THIELE-SMALL parameters. The three most important parameters include RESONANT FREQUENCY ("fs"- the frequency where the speaker moves with the least mechanical resistance), TOTAL Q ("Qts"- the "magnification" of the cone movement at its resonant frequency), and VOLUMETRIC COMPLIANCE ("Vas"- the equivalent volume of air that the woofer cone can displace for a given power input). Using these parameters we can then calculate an optimum box volume for a particular woofer and reasonably predict its frequency response.

COMMON ENCLOSURE TYPES

In the car audio world there are five types of subwoofer enclosures commonly used: INFINITE BAFFLE, SEALED BOX (closed box), VENTED BOX (bass reflex), SINGLE-VENTED BANDPASS (often incorrectly referred to as „5th“ order), DUAL-VENTED BANDPASS (often incorrectly referred to as „7th“ order). No single design is superior because each has its own compromise in performance, power handling and design complexity. The bandpass name implies a „built-in“ acoustical response which has a natural highpass response (@ 30 Hz for example) but also a lowpass response suppressing high frequencies (e.g., > 80 Hz).

INFINITE BAFFLE (fig.a) designs simply use the trunk of the car for its acoustical enclosure and the rear deck to isolate the front and rear sound paths. Advantages include simple installation and adequate performance for most systems. Disadvantages include poor power handling capacity and substandard transient response.

SEATED boxes (fig.b) offer one of the best compromises in power handling and performance. Because of the "air spring" provided by the box the advantages include simple box construction, higher power handling, excellent transient response, and smooth low frequency roll-off. Disadvantages include only moderate efficiencies at low frequencies and the need for large box volumes.

VENTED boxes (fig.c) extend the low frequency response below that of the sealed box by using a port tube. Advan-tages include extended low frequency response, lower distortion due to smaller cone movements in its passband, good efficiency, good transient response, moderate size boxes and higher power capacity. Disadvantages include increased complexity in box design and possible woofer damage due to over-excursion of the woofer cone below the cut-off frequency of the vented box.

SINGLE-VENTED BANDPASS boxes (fig.d) are relatively new (about 5 years in the car) but offer some advantages of both the sealed and vented designs. Advantages include reasonable efficiency, small box volumes, good transient response, extended low frequency performance and can be used with very high power amplifiers. Disadvantages include slightly lower efficiency compared to a vented box and increased complexity in box design and construction.

DUAL-VENTED BANDPASS boxes (fig.e) vent the sound from the front and back of the woofer through individually tuned enclosure on the front and rear of the woofer. The advantage of this design is its high efficiency over a narrow frequency band. Disadvantages include complex design and construction, large box volumes, poor transient response and susceptibilities to cone over-excursions (damage) for sound outside its primary frequency band.

ISOBARIC WOOFER CONFIGURATIONS

Increasing in popularity in recent years is the compound woofer design, more commonly known as the "Isobaric" design. Isobaric actually means "constant pressure" which is the case having two woofers moving an encapsulated pocket of air between them in the same direction.

This arrangement acts like a single speaker which effectively reduces the required box volumes for a subwoofer system by 50% which is substantial if you are space-limited. Unfortunately, the trade-off for space is the 3 dB loss in efficiency but this is usually recovered with increased amplifier power. Care must be taken to avoid air leaks between the two woofers and final speaker wiring and impedance loads must be carefully watched.

ISOBARIC CONFIGURATION (TANDEM)

SUBWOOFER ENCLOSURE CONSTRUCTION

Before starting final box assembly some basic construction issues should be mentioned:

• Infinite baffle construction in a car is done by simply cutting a piece of wood which will act as an acoustical divider isolating the front and rear sound of the woofer. This piece of wood is mounted inside the trunk of the car under the rear deck, or against the back of the rear seat, and should have some kind of caulking to seal off all residual air leaks.
• Box construction can take on nearly any shape since we are dealing with low frequencies. Odd shapes that are difficult to cut and glue should be avoided.
• Particle board, MDF, or high grade birch plywood are good materials to build boxes of thicknesses of 19 to 25 ~mm .
• All seams in the box should be glued, screwed and caulked to prevent wall separation over time due to vibration and environmental changes within the car.
• Cross bracing is important for large boxes to prevent wall vibration.
• Acoustical damping material (sheep wool or fibre-glass batting 5 to 10cm thick), attached to 50% or more of the interior walls helps reduce box noise and also increases the box volume seen by the woofer by 10 - 20% . The application of self-adhesive damping mats to the inside walls also helps to eliminate wall resonances.
• The cables running from the amplifier to the subwoofer should be as short as possible with a cable cross section of at least 4 mm2.
• The final box should be rock solid and air tight but should also remain serviceable should a woofer be damaged for any reason.
• When possible, use 10 to 15 cm diameter port tubes to avoid wind noise from smaller diameter sizes. PVC plumbing pipe in various diameters is available at most hardware stores with "elbow" pipes allowing you to bend the tubes inside the box.
• Try to always use active (electronic) crossovers, such as those built into our Velocity amps, for example.

Basic Math Calculations

To build a subwoofer box some very basic math calculations must be made accurately referencing the formulas below.

Volume and Area Calculations

Area:
Volume:

Circle (port opening)	A = 0,79 x d x d	-
Rectangle	A = h x w	-
Triangle	A = 0,5 x h x w	-
Cylinder (port tube)	-	V = 0,79 x d x d x h
Rectangular box	-	V = h x w x d
Triangular box	-	V = 0,5 x h x w x d
Cone	-	V = 0,26 x d x d x h

Speaker parameters and box calculations often need some kind of math calculations in order to make the numbers easy to work with (conversions between metric and Imperial/American units). Some common conversions are listed below:

Volume and Area Conversions

To convert from:	multiply by:	to get:
Inches	0.0254	Meters
Meters	39.37	Inches
Square inches	0.007	Square feet
Square feet	144	Square inches
Cubic inches	0.00058	Cubic feet
Cubic feet	1728	Cubic inches
Liters	0.035	Cubic feet
Cubic feet	28.3	Liters

10" SUBWOOFER • TECHNICAL DATA
Nominal diameter	10.0 in (250 mm)
Magnet weight	40 oz (1.2 kg)
Nominal impedance	4 Ω (ea. coil)
DC resistance (Re)	3.12 Ω (ea.)
Resonance frequency (fs)	30 Hz
Total Q factor (Qts)	0.42
Mechanical Q (Qms)	10,20
Electrical Q (Qes)	0.44
Equivalent air volume (Vas)	3,2 ft³ (90 ltr's)
Effective cone area (Sd)	57 in² (0.036 m²)
Compliance (Cms)	0,49 mm/N
Moving mass (Mms)	2.0 oz (58 g)
Voice coil diameter	2.0" (50 mm)
Voice coil former material	Kapton polyimide
Linear excursion (Xmax)	± 0.16 in (±4 mm)
Force factor (BI)	6.3 Tm
Acoustical efficiency (No)	0.54 %
Continuous power (Pe)	180 W (350 peak)
Sensitivity (SPL)	94 dB, 2.83v / 1m 91 dB, 1 W / 1 m

VXW 250 Recommended box designs • Boxenempfehlung • Conception recommandée des enceintes

SEALED BOX
VT	f3	SPL
Total box volume	Freq.	Mid-band effc'y (dB)
(I)	(Hz)
15	60	91
30	57	91
45	54	91
60	51	91
75	50	91
trunk	60	91

sealedbox - 30 | ... 75 |

VENTED BOX
VT	f3	fB	PL	PL	SPL
Total box volume	Freq.	Port tuning freq.	Port tube length for 70 mm i. D. (mm)	Port tube length for 100 mm i. D. (mm)	Mid-band effic'y (dB)
(I)	(Hz)	(Hz)
25	56	45	26.8	NR	91
40	45	40	14.3	28.3	91
55	38	35	10.3	26.4	91
70	34	30	16	31	91
85	31	30	10.9	22.3	91
100	28	30	8.3	17.7	91

ventedbox - 40 I … 85 I

SINGLE VENTED BANDPASS BOX
VT	f3L	f3H	fB	VF	VR	PL	PL	SPL
Total box vol.	Freq.	Freq.	Port tune freq.	Vented front box volume	Sealed rear box volume	Port tube length for 70 mm i. D. (cm)	Port tube length for100 mm i. D. (cm)	Mid-band effic' (dB)
(I)	(Hz)	(Hz)	(Hz)	(I)	(I)
25	55	200	90	15	10	4.5	10.9	92
40	35	140	75	15	25	9.3	19.4	89
55	32	110	60	20	35	12	24.2	88
70	30	85	50	30	40	11.3	22.9	87
85	NR
100	NR

bandpassbox - 25 | … 70 |

NR = NOT A RECOMMENDED APPLICATION

8622401256

12" SUBWOOFER • TECHNICAL DATA

Nominal diameter	12.0 in (300 mm)
Magnet weight	50 oz (1.4 kg)
Nominal impedance	4 Ω (ea. coil)
DC resistance (Re)	3.12 Ω (ea.)
Resonance frequency (fs)	35 Hz
Total Q factor (Qts)	0.42
Mechanical Q (Qms)	9,80
Electrical Q (Qes)	0.44
Equivalent air volume (Vas)	3,2 ft³ (91 ltr's)
Effective cone area (Sd)	79 in² (0.052 m²)
Compliance (Cms)	0,23 mm/N
Moving mass (Mms)	3,1 oz (88 g)
Voice coil diameter	2.0" (50 mm)
Voice coil former material	Kapton polyimide
Linear excursion (Xmax)	± 0.16 in (±4 mm)
Force factor (BI)	8,4 Tm
Acoustical efficiency (No)	0.86 %
Continuous power (Pe)	200 W (400 peak)
Sensitivity (SPL)	94dB,2.83v/1m 91 dB, 1 W/1 m

SEALED BOX
VT	f3	SPL
Total box volume	Freq.	Mid-band eff'y (dB)
(I)	(Hz)
15	60	91
30	57	91
45	54	91
60	51	91
75	50	91
trunk	60	91

VENTEDBOX
VT	f3	fB	PL	PL	SPL
Total box volume	Freq.	Port tuning freq.	Port tube length for 70 mm i. D. (mm)	Port tube length for 100 mm i. D. (mm)	Mid-band effic'y (dB)
(I)	(Hz)	(Hz)
25	67	55	11,1	22,6	91
40	53	45	10,0	20,6	91
55	45	40	8,7	18,2	91
70	40	35	9,1	19,9	91
85	36	35	6,4	14,1	91
100	33	35	4,4	10,7	91

SINGLE BANDPASS BOX VENTED
VT	f3L	f3H	fB	VF	VR	PL	PL	SPL
Total box vol.	Freq.	Freq.	Port tune freq.	Vented front box volume	Sealed rear box volume	Port tube length for 70 mm i. D. (cm)	Port tube length for 100 mm i. D. (cm)	Mid- band eff'y (dB)
(I)	(Hz)	(Hz)	(Hz)	(I)	(I)
25	60	160	100	15	10	NR	7,2	94
40	47	140	75	20	20	5,4	12,4	91
55	40	110	65	25	30	6,2	13,8	90
70	30	85	50	30	40	11,3	22,9	87
85	25	70	40	40	45	14,3	28,3	84
100

NR = NOT A RECOMMENDED APPLICATION

8622401256

15" SUBWOOFER • TECHNICAL DATA

Nominal diameter	15.0 in (380 mm)
Magnet weight	65 oz (1.8 kg)
Nominal impedance	4 Ω (ea. coil)
DC resistance (Re)	3.12 Ω (ea.)
Resonance frequency (fs)	30 Hz
Total Q factor (Qts)	0.49
Mechanical Q (Qms)	7,5
Electrical Q (Qes)	0.52
Equivalent air volume (Vas)	7,39 ft³ (210 ltr's)
Effective cone area (Sd)	133 in² (0.084 m²)
Compliance (Cms)	0,21 mm/N
Moving mass (Mms)	4,8 oz (136 g)
Voice coil diameter	3" (75 mm)
Voice coil former material	Kapton poly mide
Linear excursion (Xmax)	± 0.16 in (±4 mm)
Force factor (BI)	8,9 Tm
Acoustical efficiency (No)	1,1 %
Continuous power (Pe)	220 W (440 peak)
Sensitivity (SPL)	96dB, 2.83 v / 1m 93 dB, 1 W / 1 m

SEALED BOX
VT	f3	SPL
Total box volume	Freq.	Mid-band eff'y (dB)
(I)	(Hz)
40	57	93
80	46	93
120	44	93
160	42	93
200	40	93
trunk	42	93

VENTED BOX
VT	f3	fB	PL	PL	SPL
Total box volume	Freq.	Port tuning freq.	Port tube length for 70 mm i. D. (mm)	Port tube length for 100 mm i. D. (mm)	Mid-band effic'y (dB)
(I)	(Hz)	(Hz)
40	69	50	15,0	NR	93
80	49	40	9,9	28.6	93
120	40	35	7,5	23,3	93
160	34	30	7,8	24,0	93
200	31	30	4,6	16,7	93
240	28	30	NR	11,8	93

SINGLE VENTED BANDPASS BOX
VT	f3L	f3H	fB	VF	VR	PL	PL	SPL
Total box vol.	Freq. (Hz)	Freq. (Hz)	Port tune freq. (Hz)	Vented front box volume (l)	Sealed rear box volume (l)	Port tube length for 70 mm i. D. (cm)	Port tube length for 100 mm i. D. (cm)	Mid-band effc'y (dB)
40	NR>
80	52	140	800	50	30	NR	3,8	96
120	37	110	65	50	70	NR	12,3	92
160	25	100	50	50	110	10.3	29,6	88
200	15	90	40	50	150	20,9	53,4	84
240	NR

NR = NOT A RECOMMENDED APPLICATION