Exodus Audio Maelstrom-21" User manual

Exodus Audio Owner’s Guide 1
Exodus Audio
Owner’s Guide 1
Copyright  2007 Exodus Audio. All Rights Reserved.
Maelstrom-21”

Exodus Audio Owner’s Guide 2
Exodus Audio
Owner’s Guide 2
Copyright  2007 Exodus Audio. All Rights Reserved.
Introduction
Congratulations You have made a wise purchase. The Maelstrom-21” is one of the world’s
best subwoofers utilizing a patented XBL^2 motor technology, advanced inductance rings to
minimize distortion and class-leading output capability.
Great. How do I put it to use?
We offer some basic guidance in suitable enclosures. Follow our guidelines, and you will get
great results whether you build a ported, passive radiator or sealed design. All designs
have their tradeoffs so we will explain some of those in each application notes.
Performance
Operational Specifications: Measured with Praxis @ sea level, @ 55 deg F., drive voltage
>1.5V. The driver is broken-in with 12 Hours of operation with a 20Hz sine wave near full
excursion. A 12AWG jumper cable is used to connect the voice coils. The Maelstrom uses
a dual 2-ohm configuration.
Parameter Single Coil Parallel Series
Re: 1.9 Ohm 0.95 Ohm 3.8 Ohm
Le: 2.0mH 1.0mH 4.0mH
Fs: 16.3Hz 16.3Hz 16.3Hz
Qms: 3.38 3.38 3.38
Qes: 0.88 0.44 0.44
Qts: 0.7 0.42 0.42
Mms: 527g 527g 527g
Cms: 0.18 mm/N 0.18mm/N 0.18mm/N
Sd: 1550 cm^2 1550 cm^2 1550 cm^2
Vas: 605L 605L 605L
BL: 10.75 10.75 21.5
X-Max: 30% down point on BL Curve 32mm 32mm 32mm
Pmax: (Read our notes on power
handling)
1500W 1500W 1500W
SPL: 89.6 dB 1W/1M (coils in series)
Volume Occupied by Driver .2 cubic feet

Exodus Audio Owner’s Guide 3
Exodus Audio
Owner’s Guide 3
Copyright  2007 Exodus Audio. All Rights Reserved.
PHYSICAL SPECIFICATIONS
Exodus Audio Maelstrom-X
A: Overall Diameter 21.375” inches
B: Cutout Hole 19.625” inches
C: Mounting Depth 12" inches
D: Motor Width 7 .7” inches
E: Motor Depth 4" inches
Weight 53lbs
Connection Diagrams:
DUAL VOICE COIL WIRING
There are two basic means of connecting a DVC driver: parallel and series. When parallel
connecting a driver, this means connecting both voice coils to the amp in the same way. All
plus terminals connect, all minus terminals connect:

Exodus Audio Owner’s Guide 4
Exodus Audio
Owner’s Guide 4
Copyright  2007 Exodus Audio. All Rights Reserved.
For our dual 2-ohm voice coil drivers, this results in a nominal 1-ohm load (parallel connecting
voice coils of the same impedance results in half the impedance of either voice coil). This
method is suitable for some car audio amplifiers, but most home audio amplifiers like to see
a greater than a 2 Ohm load (and most are optimized around 4-ohm).
The other method of connecting DVC drivers is to wire the voice coils in series. This means
connecting from the amp to the input of one voice coil, from the output of that voice coil to
the input of the other voice coil, then from the output of the second voice coil back to the
amp:
For our dual 2-ohm voice coil drivers, it results in a nominal 4-ohm load (series connecting
voice coils results in the sum of the impedances of all voice coils). This method of wiring
gives us a much more typical impedance for home audio amplifiers.
Many pro-sound amplifiers have two channels, each capable of driving a 2-ohm load. The
Maelstrom coils have a high enough DCR that the nominal impedance in an enclosure is well

Exodus Audio Owner’s Guide 5
Exodus Audio
Owner’s Guide 5
Copyright  2007 Exodus Audio. All Rights Reserved.
within the range they will happily drive. Thus, wiring up a single Maelstrom with each voice
coil being driven by an independent channel of the amplifier is a perfectly suitable way of
powering the sub. The amplifier inputs must be summed, or wired together so that both
channels see the same signal of course.
Care
The Exodus Subs are built to the highest standards, and are designed to require a minimum
of care. Basically… use your head. If you decide to clean the cone, use non-solvent based
cleaners. Water based products are the safest.
Legal Stuff
Life Support/Mission Critical Applications:
Exodus Audio products are not fault-tolerant and are not designed, manufactured, or
intended for use or resale in hazardous environments requiring fail-safe performance, such
as in the normal operation of nuclear facilities, aircraft navigation, communication systems,
direct life support machines, heart defibrillators, or weapon systems in which the failure of
our product could lead directly to death, personal injury or severe physical or environmental
damage.
Certifications:
This product is designed to the highest standards and in accordance with all Exodus Audio
internal processes. However, this product does not carry any certification relating to
safety, standards compliance, or applicability for use in given situations. No certification is
expressed or implied. Use of this product is entirely at the user’s risk and responsibility.
Responsibility of Use:
DIYCable in no way is responsible for the use of this product. The product is capable of
causing medical damage and loss of hearing under extreme use. The customer is solely
responsible for proper use and common sense application of the product. Hearing damage
is a real threat to exposure to high SPL sound levels. Act accordingly.
Subwoofer Power Ratings:
Power ratings on transducers are just guidelines for use. They are not guarantees of the
fitness of a transducer to withstand a given power input. Why? Well, the actual power
that can be safely handled by a subwoofer depends upon several variables, including the
enclosure design, test signal or program material, amplifier details and ambient tempeture.

Exodus Audio Owner’s Guide 6
Exodus Audio
Owner’s Guide 6
Copyright  2007 Exodus Audio. All Rights Reserved.
Subwoofers by nature are inefficient devices. Most subwoofers are around 1-3% efficient,
meaning that for every 100W of power delivered to the transducer, only 1-3W is actually
converted into acoustical output. What happens to the other 97-99%? It is given off as
heat and dissipated to the environment, primarily (> 95% of it) through convective heat loss
as air passes over the voice coil & former.
Obviously, the movement of the coil & former is critical to the device being able to dissipate
heat. Consequently, if you run a 1K test tone into the driver at high power under continuous
conditions in a small sealed & stuffed box, it is easy to thermally damage a driver. If you
use a 20Hz test-tone in free-air, the same driver may be able to withstand the same power
indefinitely. For these reasons power ratings are just guidelines. Ultimately the user
must understand the conditions under which the driver is going to be used and plan for an
appropriate amount of power for the application. This is the same design paradigm that
manufactures use. Note: Highly equalized systems quickly reach thermal limits. Careful
design is required under heavy equalization especially with test-tones. Music or movies are
typically 1/8
th
power. Test tones present a MUCH higher thermal load on transducers. Be
careful testing drivers with test tones in high SPL conditions.
It is often best to be conservative with amplifier power. If you under-power the system
you will clip the amplifier at the limits of output. That will MOST LIKELY not damage the
transducer. Overpowering the transducer can quickly damage the device before the user
has a chance to adjust the system levels.
Also, amplifiers are capable of power output that
exceeds their specifications under short duration transients. These short transients can
be enough to damage the system if you are running it under full power conditions. The user
is ultimately responsible for operating the transducer within its limitations.
So what is a consumer to do? We recommend building a subwoofer like you would a bridge.
No responsible engineer would build a bridge to operate at its limit. You don’t design a
bridge to support EXACTLY the weight that it will carry under use. You design a bridge so
that it can EXCEED not only the worst-case load, but typically you would design it to have
capacity beyond its maximum expected load. While a subwoofer isn’t a bridge and it’s
failure wouldn’t be as catastrophic, it is a very good idea to build the system such that it has
MUCH higher capacity than your highest output need. Only through good design and
common-sense use will you prevent damaging the system. Since output levels required
depend upon the room, program material, user preference etc… It is beyond the scope of
this document to determine output needs.
Limited Warranty:
Exodus Audio warrants its products to be free of defects in material and workmanship for
a period of 1 year from date of purchase. Exodus Audio and/or its designated
representatives shall have all final determination about the validity of a warranty claim.

Exodus Audio Owner’s Guide 7
Exodus Audio
Owner’s Guide 7
Copyright  2007 Exodus Audio. All Rights Reserved.
This warranty shall not apply to any product that has been subject to misuse neglect
accident or abnormal conditions of operation. Improper installation is not covered under
warranty.
This warranty is limited to Exodus Audio equipment only. It does not extend to any other
equipment or product connected to or operated in conjunction with this product. We are
not responsible for any damage to other equipment or product arising from the use of this
product.
Exodus Audio’s obligation under this warranty is limited to repairing or replacing or
refunding the original purchase price (exclusive of shipping charges), at Exodus Audio’s
option, any product returned within 1 year of purchase date, provided that Exodus Audio
determines the unit is defective and has been used in compliance with the terms of this
warranty.
Subwoofer Returns
– While we do not guarantee the suitability of a specific speaker
to a specific application we provide a period of 30 days from the date of invoice in which
the customer may return the product.
All refunds require at least 14 working days for processing. This does not
include holidays or weekends. Do not contact customer service unless your return has
taken longer than 21 working days from the date of it’s arrival at DIYCable. The
following conditions apply to full refunds:
• The speaker must be in the new condition. This
includes no mounting
marks or scratches, no solder on the connectors, no sealing caulk,
dirt, sawdust, or other debris.
Speakers showing mounting marks or other
indications of use will be evaluated and a restocking fee
starting at 25%
deducted from the refund amount. In extreme cases no refund or credit may be
offered. Our intention is not to offend or punish people returning product. The
bottom line is that if we cannot resell the product as new we cannot offer you a
full refund. If we have to sell the product as b-stock or determine that it doesn’t
meet our standards for resale even as a b-stock product the customer will not
receive a refund.
• Product must be returned in all original cartons outer shipping cartons and boxes.
This packaging includes all internal plastic bags or printed manuals. The product
must be in NEW condition returned in ORIGINAL packaging.
• Package the product to protect it from damage in route to DIYCable. Insure the
package for the value of the product. In the event the returned package is damaged
in route to DIYCable due to insufficient packaging the customer is responsible to
file the claim with the shipper.
amaged Product

Exodus Audio Owner’s Guide 8
Exodus Audio
Owner’s Guide 8
Copyright  2007 Exodus Audio. All Rights Reserved.
Speaker Defects occur even in the most expensive of speakers from the most respected
companies. Contact DIYCable immediately if you suspect you have received a defective
product. Products that have obvious defects will be replaced at our cost or we will
arrange for a credit based upon the customer’s preference.
There are times when a customer may suspect a defect that is not obvious. Unless there
is an obvious defect (broken part missing components etc.) we reserve the right to
inspect and test the transducer to confirm that it is in fact defective. Often a mounting
problem or a system problem can appear like a defective transducer (clipping popping or
rubbing caused by obstruction hitting the cone or suspension components). If there is
some doubt concerning the integrity of the product we encourage the consumer to work
with our technical support to troubleshoot the problem avoiding costly shipping and
replacement of parts that may not be defective.
Customers are ultimately
responsible for troubleshooting the problem. Our technical support will do the best
they can to help but we are at a decided disadvantage by being at a remote location.
Email and phone calls are not as effective as having the product in your hands to test. In
the end the customer is
SOLEL responsible for system problems related to the use of
the transducer or any damage caused to the system.
Parts returned will be tested for rub/buzz and T/S parameters to verify the integrity of the
transducer. If the transducer is determined to be non-defective the product will be
treated as a returned new part with the same conditions outlined above in the Subwoofer
Returns section including restocking fees for cosmetic damage non-payment of shipping
charges and requirements for all original packaging.
All returned products require at least 14 working days for processing!
AMAGE MERCHAN ISE RETURNS
Contact DIYCable within 5 days of receipt. Carriers will not permit claims after 5 days.
We will file a Damage Inspection Claim which results in a carrier follow-up to inspect
your package. Retain all boxes labels and packing materials until the claim ha s been
approved. We will proceed with a replacement shipment once the carrier notifies us of
claim approval. Note: Truck freight shipment damage must be reported directly to
freight carrier.
All Returns should be shipped pre-paid to:
DIYCable
175 South Bay View Ave. Unit 23
Port Angeles, WA 98362
360-452-9373