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The Model 50/Jamaica Speaker


"... the Model 50 produced thunderous bass and never lost its composure at very high listening levels."

NSMT Loudspeakers Model 50/Jamaica

"I'm driving this speaker either with 1 watt or 4 watt SET amplifiers with no difficulties regarding volume levels, bass extension, and overall dynamics.  I get easily over 100dB if I really want to listen that loud..." (Terry London, Audiogon)

Shown: satin black and natural cherry

Price per pair: $2,495 per pair.

The price includes our large outrigger kit with eight standard black speaker spikes, a $175 value.



The first review of the Model 50/Jamaica speaker by Terry London of hometheater review is in and here are some excerpts from the review:

"The overall appearance and build quality lead to a very attractive speaker..."

"The Model 50 produced a soundstage that seemed that I was in the middle of a large crowd, totally transcending the walls of my listening space."

"Bob Marley and his band seemed to be centered about 30 feet in front of me and the rest of the crowd was around me. The Model 50 completely vanished into this space."

"... the Model 50 produced thunderous bass and never lost its composure at very high listening levels."

His wife's comment: "This might be the most beautiful sound you have ever had in this system."

"The Model 50 speaker's performance shines in the areas of tonality, details are easily heard because of its transparency, it's a very dynamic design that gives life to the music, it produces a reference level of sound-staging/imaging, and because of its double transmission line loading you won't have to get a subwoofer for music or movies. "

You can read the full review here.

A cutomer's comment:

"I bought these speakers from you a couple of years ago and am sitting in front of them as I type. They are remarkable. .. I wasn’t so sure about the bass when I first got them, I should not have worried. Now that the drivers have moved in and out a few billion times these things make my head shake in disbelief. Anything I ever wondered about simple circuits, DHT triode amps, NOS dacs, AND well designed transmission line speakers has been achieved! Best of luck with the Clairvoyant’s. I can’t imagine how they must sound but, I’m good."

The active version of the Model 50/Jamaica is here.


The Model 50 AKA Jamaica is a two-way, time coherent, double transmission line system that reproduces music with excellent clarity, musicality, spatial presentation, dynamics, and speed.


The lasting impression one gets from visiting Jamaica is the sheer prevalence of music. In terms of the quantity and quality of music produced by Jamaicans, as Shaggy and Sting argue, Jamaica a country of roughly three million people, punches way above its size. Drive into a small town and chances are you car will be rocked by bass dominant reggae, dancehall, ska, rocksteady or mento music emanating from large speakers somewhere in the square.


While we can't replicate the sheer power and grandeur of those large speakers we wanted to produce a compact, affordable, powerful, audiophile speaker with incredible dynamics that much like Jamaica punches above its size in performance and value and can replace much larger speakers.


To accomplish this, we use two eight inch shallow high power paper cone woofers and a recessed one inch wave guide soft dome tweeter in a MTM arrangement that is time coherent and wired to simulate a point source in our proprietary DTL double transmission line cabinet design.


The woofers are implemented crossover-less to cover the fundamental frequency of instruments and voices from 35 Hz to 4,750 Hz. Without a crossover there are no phase anomalies that tend to muck up the sound in this frequency range. The woofers are seamlessly integrated with the tweeter which handles harmonics above 4,750 Hz. The tweeter is implemented with a 12 dB crossover to protect it at extremely high volume levels.


These design choices allow our Jamaica speaker to deliver stunning dynamic performance and much like Jamaica to punch above its size in performance and value. It has a humongous wide and deep soundstage, a spectacular midrange, images on par or better than some of the best minimonitors, it reproduces vocals beautifully, and projects sound with the authority that makes every recording sound live.


With a sensitivity of 100 dBs, the Jamaica speaker system can easily be driven to loudness of about 105 dBs with as little as 5 watts RMS at a distance of about 8 feet from the speakers. With 1 watt you can drive the Jamaica speaker system to about 102 dBs at about 6 feet from the speakers. 


The Jamaica speaker system proves there is no longer a need for monstrous speakers to get live sound pressure levels. 


Being thankful for the inspiration, we dedicate our Model 50 Jamaica speaker to all the musicians and singers and people of Jamaica.

NSMT Model 50


Drivers: Custom hi-power, high sensitivity 8 inch paper cone woofers with phase plug and modified 1 inch soft dome tweeter arranged in quasi point source time coherent MTM arrangement

Drivers are all wired in positive polarity to preserve the waveform of original recording.

Time Coherence: Time coherent, minimum phase design

Crossover: Crossover-less broad band woofers, second-order crossover to tweeter.

Connectors: five-way insulated gold plated binding posts.

Single wire or optional Bi-wire-able/Bi-amp-able: Custom biwire silver plated copper wire encased in OFC copper jumpers

Wiring: MasterSource multi-strand oxygen free copper wire to tweeter and woofers.

Cabinet: Made from certified “green” real red birch wood laminated CARB 2 “formaldehyde-free,” anti-resonant medium density fiber board. Only non-toxic paints and glues are used.

Support: Custom CNC machined aluminum outriggers with spikes

Warranty: Limited 5-year warranty.



Dimensions: 42 X 9.5 X 9 inches (H X W X D) with grill

Frequency Response: 42Hz – 19.5kHz +/- 3.5 dB

Bandwidth: (-10 dB): 28 Hz - 20 kHz

Sensitivity: 100 dB 1 watt/meter

Rated Impedance: 8 ohms

Minimum DCR: 7.7 ohms

Recommended Power: 1-500 watts

Shipping Weight: 60 pounds each


Role Audio dual transmission line logo
Patent Pending

DTL is a trademark of Role Audio Company



The previous NSM (NSMT) Model 50 was highly regarded. In his 1995 review of the Model 50, Julian Hirsch of Stereo Review had this to say: 

"The NSM Model 50, despite its conventional appearance, is not just another conventional column loudspeaker. The goal of its designers was to produce a "compact acoustic suspension system with the bass response of a subwoofer, and the imaging and soundstaging of a minimonitor."

"The Model 50's measured sensitivity was 85 dB, exactly as rated. The room response above a few hundred Hertz was very uniform and smooth, with a variation of only +2.5 dB from 300 Hz to 20 kHz."

"Even at 32 Hz, the output was only 6 or 7 dB below the average midrange level, and (as listening confirmed) it was perfectly audible and usable at that frequency."

"The Model 50's group delay (an indicator of its phase linearity) was among the lowest and most uniform we have measured to date, with a peak-to-peak variation of less than 0.2 millisecond from a few hundred Hertz to 20 kHz."

"All of this suggests that the NSM Model 50 is a very good speaker, which had been apparent from our first listening. How did it sound? For one thing, it was unobtrusive, in the sense that we were never particularly aware that the sound was emanating from those black boxes, even when quite close to one of the speakers."

"I suspect that the NSM speakers were the more "accurate" of the two (whatever that may mean), and that its spatial performance was more realistic. I like sonically-unobtrusive speakers that do not call attention to themselves yet give a believable impression of a concert-hall performance. By those criteria, the NSM Model 50 is a great success. Hear it for yourself if you can."

When we ceased production of the Model 50 in 1998 its price was $1,795, which is equivalent to $2,785 today. Today (8/28/2018) we are introducing a worthy successor to the original Model 50 at an introductory promotional price of $1,795. We will make subsequent price increases until we reach $2,785, the equivalent price of the original Model 50.