Reference 811w,1011w,1211w OM 7/14/98 10:31 AM Page 3
POWER-HANDLING LIMITATIONSSPECIFICATIONS
The power-handling capability of anyY Voice-coil overheating and burning dueReference 811w
woofer is related to both its ability to dissi-to overexcursion are often caused by over-Configuration:8" woofer
pate heat and the maximum excursion lim-driving an amplifier into "clipping." ANominal Impedance:4 ohms
its of its cone. Once the speakerOs voice coilseverely clipped signal, or squarewave,Power Handling:200W
moves outside the magnetic gap, powercontains nearly twice the power of a cleanSensitivity @ 2.83V/1m: 91dB
can no longer be converted into motion andsine wave at the same level. Bass thatFrequency Response:50Hz �1kHz
all the amplifierOs power is converted intosounds broken up and distorted at higherMounting Depth:4-3/8" (112mm)
heat in the voice coil. This voice-coil heatingvolumes usually indicates that the amplifierCut-out Diameter:7-1/8" (181mm)
is the largest detriment to speaker longevi-is clipping (i.e., being asked to deliver
ty, so overexcursion should be avoided.power beyond its rated power).Reference 1011w
Since speaker-cone excursion is differentY Infinite baffle or Ofree air� mountingConfiguration:10" subwoofer
for each type of enclosure, power handlingapplications allow for greater cone excur-Nominal Impedance:4 ohms
is different for each enclosure.sion than subwoofers mounted in an enclo-Power Handling:225W
Sealed enclosures exert the most controlsure. In order to compensate, recognizeSensitivity @ 2.83V/1m: 92dB
over the motion of a subwoofer becausethat the power-rating value of the sub-Frequency Response:40Hz �500Hz
the air inside the box acts like a springwoofer will likely be half its rated power inMounting Depth:4-5/8" (118mm)
against the motion of the woofer cone.this application.Cut-out Diameter:9-1/8" (232mm)
Larger boxes allow for more excursion,Y Study the excursion curves on the
thus providing more low-frequency outputenclosed Reference series data sheet andReference 1211w
for the amount of power used. When placednote the differences for different enclosureConfiguration:12" subwoofer
in a sealed box larger than the Vas of theapplications. The type and size of box usedNominal Impedance:4 ohms
subwoofer, it will perform as if it were in will produce different excursion demandsPower Handling:250W
an infinite baffle installation.on the enclosed subwoofer and, conse-Sensitivity @ 2.83V/1m: 93dB
Vented enclosures have the lowestquently, different levels of power handling.Frequency Response:30Hz �500Hz
amount of excursion for the amount ofAs long as recommended parameters areMounting Depth:5" (127mm)
sound output. This is a result of port outputused, the subwoofer will perform properlyCut-out Diameter:12-1/8" (308mm)
reinforcing the sound output from thein its enclosed environment. However, any
woofer. The mass of the air contained in thedesign deviation may result in less than
port provides an acoustic load on theoptimum performance, and may also sub-
wooferOs cone at the tuning frequency, andject the subwoofer to overexcursion (i.e.,
this added mass decreases woofer-conewhere the voice coil leaves the gap) that
excursion. Vented boxes do not providecan eventually damage the speaker. For
adequate woofer control when drivenadditional help with this issue, please con-
below the port tuning range, so propertact your authorized Infinity dealer.
design is important. A vented bandpass box
will have the lowest overall cone excursion,
provided a subsonic filter is used. |
ACEC
