Beta Ten.dvc Sealed Enclosure Flat Response

SUBWOOFER ENCLOSURE TRADE-OFFS

BETA TEN.DVC SEALED ENCLOSURE

BETA TEN.DVC VENTED ENCLOSURE

BETA TEN.DVC BAND-PASS ENCLOSURE

Subwoofer enclosures are classified as sealed (acoustic suspension) or ported (bass-reflex), and can be built in many configurations. Here we discuss three popular box types and encourage you to compare their response curves, noting the differences in Beta Ten.dvc output level and frequency response versus volume in sealed, vented, and single-reflex band-pass enclosures.

A sealed enclosure is the smallest and simplest to build, with high power handling, good phase coherence, and the most predictable response, at the expense of some- what diminished sound output. If amplifier power is not a concern, this is the best choice for most systems, pro-

Beta Ten.dvc

(side view)

VBOX = Box Volume

(see responses below)

	L = length	Port
	(see responses	Port
	(see responses
Beta Ten.dvc	below)
Beta Ten.dvc
(side view)
VBOX = Box Volume		D = diameter
VBOX = Box Volume		(see responses
(see responses below)		(see responses
(see responses below)		below)
		below)

Beta Ten.dvc

(side view)

VBOXR = Box Volume Rear

(see responses below)

L= length	Port
(see	Port
responses
below)

D = diameter

(see responses

below)

VBOXF = Box Vol. Front

(see below)

viding the highest output at the lowest frequencies.

A vented enclosure adds a port (or vent) tuned to the speaker’s resonance in the box to help boost sound out- put by “tuning” the rear sound waves so they add to the front ones. It is more efficient than a sealed box above the tuned frequency, but more difficult to build properly. For frequencies below the tuned range, output is less- ened due to sound cancellation, and there is a 180- degree phase shift at the tuned frequency. Other draw- backs are the increased box size for the added port and diminished power handling due to woofer over-excur- sion at frequencies below the tuned frequency.

Asingle-reflex band-pass enclosure counteracts the sound cancellation properties in vented designs by iso- lating the subwoofer from the port within its own enclo- sure. It offers higher power handling, and an automatic band-pass response to help roll off higher frequencies. However, it has a 180-degree phase shift at the tuned frequency. Also, complexity and size are increased, due to separate front and rear chambers, and it requires adding substantial midbass drivers elsewhere in the car.

We recommend a sealed enclosure for the Beta Ten.dvc. Depending on your taste in music, you can select a box volume for a flat, enhanced, or extended bass response (see graphs on right). The flat response is optimum for all enclosures and types of music. The enhanced sealed box provides a “tighter” bass, great for rock and rap. An enhanced vented box has increased output, but with diminished transient response and power handling. The extended sealed box is more efficient at the lowest fre- quencies, providing added bass boost for jazz and classi- cal music, but with diminished power handling. The extended response curve provides the best power han- dling for vented enclosures.

For more help, please call Infinity technical support at: (800) 553-3332

dB (Normalized)

0Close-Field (In Car)

-10

-20				VBOX*= 0.50 ft3
-20				VBOX*= 0.50 ft3
-30
-30	Free-Field
	Free-Field
						Freq.
10	50	100	500		1k	(Hz)