ULTIMATE Nobelium
SERIES SUBWOOFERS
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Nobelium 10
Nobelium 12
Nobelium 15
Active filter
Amplifier
Connection in mono bridge mode with an active x-over. Voice
coils connected in series. If you have a 1 ohm stable amplifier
the voice coils should be connected in parallel for best
performance (for example on a DLS monoblock).
Connected with a 12 dB passive low-pass x-over = 10 mH coil
in series and a bipolar capacitor of 300 microFarad in parallel.
Crossover frequency is 95 Hz.
Valid from 2005-07-04
WELCOME
Thank you for buying a DLS ULTIMATE Nobelium subwoofer.
The subwoofer must be installed correctly in order to work well.
This manual will show you how to install it like a pro. Please
read the entire manual before beginning the installation.
Install the subwoofer yourself if you feel confident with our
instructions and if you have the proper tools. However if you
feel unsure, turn over the installation job to someone better
suited to it.
The speakers are designed for enclosure mounting. In "open
air" installations the power handling capacity is reduced by 30%
from the nominal value. We dont recommend ”open air”
installations for Ultimate Nobelium subwooers.
CONNECTION OF SUBWOOFER
How to connect depends on what type of amplifier you use.
The best is to follow the instructions given in the manual for the
amplifier. Most amplifiers today have built-in lowpass crossover
and possibilities to connect your subwoofer in bridge mode.
Two 4 ohm subwoofers are often connected in stereo mode
since most amplifiers can´t handle bridge mode loads below 4
ohms.
The Iridium subwoofers have dual, four ohm, voice coils. Each
voice coil has an impedance of 4 ohms. If they are connected in
series the resulting impedance is 8 ohms. If they are connected
in parallel the resulting impedance is 2 ohms. Make sure to
connect in a way that don´t ruin the amplifier. If you have a DLS
Ultimate amplifier it´s possible to connect the voice coils in
parallel, these ampliers are 1 ohm stable.
We also recommend the use of a subsonic highpass filter. This
gives a better bass reproduction with less "rumble". In most
DLS amplifiers this feature is already built-in.
For wiring use high class speaker wires, min AWG13 (2.5 mm
2
).
For example
DLS SC 2x4.
If you have an amplifier without built-in crossover you must use
a passive crossover between amplifier and subwoofer like in
this example, one crossover for each voice coil.
Component values are for 4 ohms.
SUBWOOFER ENCLOSURES, GENERAL
Build your enclosure in a stable and airtight material. The best
is MDF-board, 19 mm, or particle board, 22 mm. Larger
enclosures must have bracing inside to avoid vibrations. The
enclosure must be completely airtight. Use sealing compound
in all joints, also around the cable terminals. The size of the
enclosure is decided by the speaker data.
SEALED ENCLOSURES
Sealed enclosures are easy to build. The size is not critical, but
it can´t be too small. The speaker data such as Fs, Qts, Vas
and X-max decides the size of the enclosure.
Large speakers need larger boxes. Two speakers need a box
of the double size etc. The enclosure must be completely air-
tight.
A sealed enclosure should be filled with acoustic wool up to 75
- 100%.
A sealed enclosure has a lower efficiency than vented
enclosures but they can handle high power and are easy to
build.
A subwoofer in a sealed enclosure creates a tight bass suitable
for the audiophiles listening to classical music, jazz and soft
rock. The Nobelium subwoofers can be used in sealed
enclosures.
VENTED ENCLOSURES
A speaker in a vented enclosure has a higher efficiency (3 dB)
and higher power handling capacity than in a sealed enclosure.
In a vented enclosure the sound from the speaker and the port
work together creating a higher sound level. The sound from
the port must come out in the same phase as from the speaker
otherwise the result is bad.
The size of the vented enclosure is decided by the speaker
data just as for the sealed one.
The size of the vehicle often decides the practical size of the
enclosure. A smaller enclosure has a higher resonant frequency
than the larger one. The size of the enclosure should not be so
big that the speaker plays below it´s own free air resonance
(Fs), if so the power handling capacity drops.
The port does not have to be fully inside the enclosure as long
as the area and length are correct. Sometimes you need two or
more ports in an enclosure. You can convert from one to two or
more ports as long as the total port area is the same.
All Nobelium subwoofers can be usedl in vented boxes.
BANDPASS ENCLOSURES
In all bandpass enclosures the speakers are hidden inside the
enclosure, all sound is coming out through the ports. There are
different types of bandpass enclosures and they have in com-
mon that they are a bit more difficult to build. DLS Iridium
subwoofers can be used in bandpass enclosures.
IMPORTANT!
Think of the speaker weight when you install it. If you don´t
mount it properly it can come loose.
*Nobelium is a radioactive metal with atomic number 102. It is named after the Swedish scientist Alfred Nobel
