State of The Art



A Low Distortion Subwoofer System
for possible use with the LCM-1 Speakers

Extends the Bass Response down to below 16 Hz

Increases the maximum overload of the LCM-1 by 12 dB at low frequencies

Deep bass ambience in large halls is
now reproduced faithfully

May be used as stand for LCM-l's or
used separately.

        Smarting under the complaints that the LCM-1 Speaker system would not crack the ceiling or allow owners to break leases (what can you do with the guy in the next apartment when he asks you to turn up the system 'cause it sounds great?), we at Dayton Wright, ever concious of the need for good customer relations, decided to respond to these complaints, and our answer is the ICBM-1 SubWoofer System.  Designed to have low distortion as well as extended frequency response, and with an efficiency allowing it to be driven with the same power amplifier used for the LCM-l's (indeed the necessary hi-pass part of the crossover is built in), the ICBM-1 came out somewhat larger than we had anticipated.  Nevertheless, we consoled ourselves in the thought that because it is only eleven inches wide (or as we would say in Canada, 28 centimeters wide).  Thus when it is used as the support for the LCM-1, only that modest width should be visible to the listener.

        In designing the ICBM-1 to be used with the LCM-1 we employed some proprietary crossover design techniques, and with them were able to obtain a very smooth transition between the two speaker systems.  The combined system has a much deeper bass without losing the natural quality that characterized the LCM-l's.  The two units when used together are (acoustically at least) a very satisfying combination!  And not only will the units allow you to break leases, they could probably lead to divorces as well.  It has been suggested, with, we suspect, some levity, that it could provide the ideal answer to bill collectors, especially when dropped from a fifth story apartment window. (ICBM stands for Intermediate Cost Bass Module, not for Incredibly Clumsy Bulky Monster!)


ICBM-1 Subwoofer with attached

         In plain English, the ICBM-1 is hard to overlook.  With dimensions of 2 feet deep by 4 feet high by I 1 inches wide (And once again for Canadians that's 61 cm. x 122 cm. x 28 cm.) with the grill sticking out another 1-3/4 inches, it has been described, at best, as a desirable intruder.  A pair of mounting clips that screw to the back of the LCM-1 allows it to be mounted on the front of the ICBM-1, but increases the depth by another 14 inches (35.6 cm).

         The finish is black vinyl imitation leather which will stand up equally well to children, household wear and tear, and verbal abuse.  The edges have been rounded off as in the LCM-1 so that personnel dents will be less painful.  This rounding of the cabinet edges also makes it less likely to be damaged either when it is shipped or when your cat assaults it.

         The front of the unit is recessed sufficiently so that we can mount the crossover network outside the cabinet, and to provide clearance for all the wiring to the ICBM-1 and LCM-1.  The latter mounts at the top front, with the Sub-Woofer grill underneath.

         An optional full length grill is available for audiophiles who wish to hide the ICBM-1 (lots of luck) as it can be used at a modest distance from the LCM-1 speakers.  Some dealers have even gone so far as to suggest that the ICBM-1 works very well with other manufacturer's loudspeakers too.

         Two ten inch Drivers are used, with a power handling capacity of over 200 watts.  The crossover is of the "Variable Rate" type so that the sub-woofer insinuates itself into the operating range of the system rather than announcing "O.K. Guys, here I am ... bring on World War Three"!  The problem with subwoofers of that type is that the explosions sound somewhat out of place when you're playing Mozart.

         As we noted, the ICBM-1 Sub-Woofer can be used separately from the LCM-1.  Its width will allow it to be hidden behind desks, elephants, sofas, etc.  It need not be right beside the LCM-1, but on the other hand it should not be too far away.  Thus, if your apartment is on the lower east side of Manhattan, it is not recommended that the Sub-Woofers be placed in St. Louis (unless the wife really insists on it!).

         In order to insure that the stability of the LCM-l/LCBM-1 is as rock-solid as possible, two alternate mountings are provided.  The bottom of the ICBM-1 has four threaded inserts near its corners.  These will accept either the "glides", or the rug-piercing pointed studs.  The Audiophile is cautioned against resting these on his foot as they are also both shoe and flesh piercing!  It is also wise to be sure that you know exactly where you are going to place the ICBM-1 before you use these points as once in position you may find that you've spiked the system to the floor!  With this potential problem in mind, the mounting for the LCM-1 has been designed so that it can easily be removed from the ICBM-1 Sub-Woofer.  Thus, we suggest that the ICBM-1 /LCM-1 System (without the rug-piercing points) be slid into position (with the LCM-1 attached), the LCM-1 removed and the Sub-Woofer tipped forward onto its face.  In this position the pointed studs are screwed in place and the Sub-Woofer tipped back upright again and the LCM-1 replaced.  The process is quite simple and can be done when someone else is out shopping!

        When used with the ICBM-1, the LCM-l's should be placed at least 2 feet away from the wall behind them. (in point of fact, when mounted on the ICBM-l's the LCM-l's cannot be placed any closer than 2 feet from the wall behind them!)

        The efficiency of the units allows them to function quite well with moderate-power receivers, although the specifications of lower-power units should be checked to be sure that they will drive speakers of 4 Ohm Impedance.

        ANOTHER WORD OF WARNING!  Do not let the dealer talk you into taking the ICBM-l/LCM-l's home to try-out if you value your marriage, or are afraid of a hernia.  You may well find yourself trading the former for the latter!

(And sure we could have gussied them up with Molded Urethane trim, added bronze handles, and sold them as coffins for short Siamese twins but we thought that when the addition of the ICBM-1 improves the LCM-1 as much as they do, our dealers deserved another opportunity to make a profit!)

        If youre feeling especially brave, the IBSM-1s can be used with the XAM-4s providing that the ICBMs are far enough away so the radiation pattern of the XAM-4s is not affected.


Finish: CABINET - Black Vinyl Only

Physical Height 122 cm (48 ins)
Width 28 cm (1 1 ins)
Depth 61 cm (24 ins) + 35.6 cm
(14 ins) for LCM-1 on front
Weight 30 kg (66 lbs)

Drivers .... 2 Long Throw Woofers 25.5 cm
(1 0 ins) each

Frequency Response Extension. . To below 16 Hz

Crossover.  Asymmetrical/Special Derivation
60 Hz

Impedance.  Minimum 4 ohm, Nominal 5.5 ohms
with LCM-1 unit

 ICBM-1 with grill removed

97 Newkirk Road North, Richmond Hill, Ontario L4C 3G4
(416) 884-8586


Hear this equipment at:

Printed in Canada

© 1984, 1997 Wright Electroacoustics


Return to Home Page