Speaker Asylum: REVIEW: Carolina Audio JTM Speakers by waynes

Model:	JTM
Category:	Speakers
Suggested Retail Price:	$1500
Description:	Transmission line Single Driver using the Jordan jx92s
Manufacturer URL:	Carolina Audio
Model Picture:	View

Review by waynes ( A ) on June 11, 2004 at 21:01:23
IP Address: 149.174.164.73

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Should I begin, like a professional audio reviewer, with a few paragraphs about my passion for mountain biking, the joys of landscaping, or a discussion of recreational soccer and its affect on the Achilles tendon? Naaahhh. I’ll just get right to the point. I love these friggin’ speakers.
I have owned Carolina Audio JTM speakers for about five months. I was hoping to finalize the rest of my system before writing a review of the JTMs because I’ve found that these speakers reward the listener for every upstream improvement. But getting the system together is taking a bit longer than expected, so I’ll write now and update later. The update will take the form of a review of the final additions, which I think will also be of interest to Inmates (Scott Nixon mono-block amplifiers, an updated beta version of Modwright’s SWL 9.0 line stage, and a Ginko Audio Rack)
Since I haven't previously posted such details, I’ll describe my listening room in detail to provide context for my comments.
LISTENING ROOM:
Definitions- “Left,” “Right,” “Front,” and “Rear” are defined from the perspective of a listener looking toward the speakers. The speakers are positioned near the “front” of the room; i.e., the wall behind the speakers is defined as the “front wall.” The listening end is the “rear” of the room; i.e., the wall behind the listener is defined as the “rear wall.” From the perspective of that listener, the room is entered through a large opening at the left rear.
My listening room is 17.5 ft x 24.5 ft. As previously indicated, my speakers are positioned across the front wall, which is the shorter wall. The speakers are positioned about 7 ft into the room and about 3 ft away from the side walls. That puts them about 11.5 ft apart. The room has a volume ceiling that rises from a height of about 7 ft at the front of the room to a maximum of about 13ft at a point that is about 8ft from the back wall. The ceiling height then drops to about 8.5 ft (for the remaining 8 ft of the room). The back wall of the room is foreshortened; it’s only about 9.5 ft (rather than 17.5 ft) across. The remaining space – about 8 ft – serves as an opening into a dining room (17.5ft x 19ft). Also, the left sidewall is foreshortened; it’s only about 16.5 ft (rather than 24.5 ft) in length. The remaining space – about 8 ft – serves as an opening to a foyer (20ft x 10 ft x 16ft in height). If you’re following this, you’ll appreciate that the 8 ft that is removed from both the left side-wall and the back wall defines an 11.3 ft “diagonal” opening through which the room is entered. This is a long-winded way of saying that I’ve got a large room that opens to large ancillary volumes.
The front wall has a bank of windows, which are covered by accordion-style blinds. The right side wall also has a window, which is likewise covered by accordion-style blinds. The room is carpeted and includes a large leather L-shaped sectional, a wood cocktail table, and two fabric-covered club chairs. The listening position (on the sectional) is about 12 ft away from the speakers. The speakers are about 11.5 ft apart and toed in so that the single driver of each speaker is aimed just outside of the listening position.
JTM CONSTRUCTION:
Each speaker cabinet (3 ft tall x 1 ft wide x 4 in deep) includes a single Jordan jx92s full-range driver. The volume within each cabinet is segmented into three communicating chambers that define a quarter-wave transmission line. The speakers are ported at the bottom of the cabinet to enable near-wall placement. Workmanship is quite good; the speakers are solidly built and have an understated black-satin finish. Custom veneers are available at additional cost.
According to the Mr. Ronnie Thackeray of Carolina Audio, the jx92 driver was selected for use in the JTM due to its extraordinarily flat response. The Jordan website provides a transmission-line design for use with the jx92 driver, but Carolina Audio has modified this design for the JTM. In particular, Ronnie tapers the transmission line, which has been found to result in improved sound relative to the nominal design.
THE SOUND:
I’m not a musician, but I do attend classical and jazz concerts fairly frequently and have a reasonable idea of what most instruments sound like. To me, every instrument that I hear reproduced by the JTMs, be it piano, violin, bass, drum, cymbal or saxophone sounds like the real thing. While the JTMs can’t reproduce the lowest registers, they go surprisingly deep. And what they do reproduce is very tight with excellent definition. Forget one-note bass – you’ll hear overtones that you haven’t heard before.
I listen with a sub – the Paradigm Servo 15 – some of the time. I do this to recover the lowest octave and, also, the sub unloads the speakers when I crank the volume. For most listening, the JTMs provide me with plenty of output and dynamics. But because my listening room is so large (especially considering the contiguous spaces), as I crank the unassisted JTMs, the sound compresses. With the sub in the system, I freely crank the volume with no such loss of dynamics. In smaller rooms, I doubt that this problem would arise – at least for those that want to listen at reasonably-sane levels. I do perceive some loss in definition in the bass with the sub in; but this might be a pyscho-acoustic phenomena. In a smaller room, I would listen quite contentedly, and probably preferably, without a sub.
A final observation on listening levels - these speakers do quite well at very low volumes. Because I often listen when the rest of the house has turned in for the night, I keep the volume to barely more than a whisper. The JTMs remain very coherent and enjoyable at these low levels.
Imaging, of course, is somewhat room dependent. In my room, the JTMs image beautifully. They literally disappear and I get a deep, layered and wide soundstage. Image placement is steady and precise.
As implied above, I’m in the process of building a system. The speakers came first, and I have heard the affect of each upgrade. I like that. I wouldn’t say that the JTMs are finicky; rather, they are revealing of what’s upstream. For example, I readily heard the difference when I upgraded from various Pioneer source components to the EAD UltraDisc 2000. Perhaps no surprise there. I’ve also readily heard the difference between the preamp in the Trivista Integrated, a Pass Labs X2 preamp, and a beta unit of the Modwright SWL 9.0 tubed linestage.
I’ll report more on the Modwright linestage when I get an updated version of the beta unit. Suffice it to say that I’m very impressed with the beta unit that I’ve got, and I understand from Dan Wright that there have been subsequent upgrades to the power supply that have taken the unit to the next level (or next two or three levels). Among other sonic improvements, this upgrade will undoubtedly improve bass extension, which is the only area in which this otherwise excellent unit is somewhat lacking. As it is now, I’d say that the linestage offers excellent value at its anticipated price (about $1200). In final form, it will only get better.
I’ve also heard a difference (increased soundstage width and improved inner detail) when I placed a Ginko Audio Cloud 10 vibration control platform under my amp, pre-amp, and cd-player (individually and then collectively). And the difference between interconnects, speaker cables and power cords were readily apparent through the JTMs. On that subject, I’ll note that while the Carolina Audio interconnects and speaker cables nicely complement the JTMs, to my ears, the Audience AU24 interconnects and speaker cables are in another league. There is a vividness and natural balance to the presentation with AU24 that is not matched by the Carolina Audio wire. This is perhaps not surprising in view of the price differential (a difference of $300 for 1-meter interconnects and a difference of $1100 for 10 ft of speaker cable). I mention it simply to note that nothing that I place upstream of these speakers is “too good” for them. Every time I upgrade, I’m rewarded with improved sound.
Perhaps it’s a bit ludicrous that my AU24 speaker cables retail for about the same price as the JTMs. In this case, I think it’s simply a matter of the speakers being way under-priced in terms of their performance relative to the competition. The least expensive speaker that I think I like more than the JTMs is 3x its price. I prefer the JTMs to many speakers that I’ve heard that are about 4x its price. Chalk that up to no dollars spent on advertising, no dealer network, and ethics.
If I were asked to characterize the JTMs in a sentence, I think I’d say that they love music. There is a delicacy and ease in the way that music is presented by the JTMs that makes them a joy to listen to. That’s not to say that they are overly polite; rather the presentation seems effortless. I don’t know whether that’s due to their flat response or extraordinary transparency and amazing inner detail. Whatever it is, I can’t stop smiling as I listen.
Carolina Audio offers a 3-week in-home trial. If you are in the market for speakers that sell for about $2k or more, and you are willing to suspend your disbelief long enough to listen to them, do yourself a favor and order a pair.

Product Weakness: Limited Low Bass
Product Strengths: Play very well at low volume, imaging, coherency, transparency,and tonal accuracy

Associated Equipment for this Review:
Amplifier:	Musical Fidelity A3CR dual mono amplifier, [Musical Fidelity Trivista Integrated Amp]
Preamplifier (or None if Integrated):	Beta Version of the Modwright’s SWL 9.0 line stage, [Pass Labs X2]
Sources (CDP/Turntable):	EAD UltraDisc 2000, [Pioneer PD-59 cd player, Pioneer Elite CLD-79 Laser Disc Player with Theta Chroma DAC]
Speakers:	Carolina Audio JTM, [AP Virgo II, Totem Mani II, Snell LCR 500]
Cables/Interconnects:	Audience AU24 single run (4.5m), Audience AU24 single-ended (1 m), [Shunyata, Analysis Plus, Carolina Audio, Audioquest, Tara, MIT]
Music Used (Genre/Selections):	Jazz, Classical, Blues
Room Size (LxWxH):	24.5ft x 17.5ft x 7-13ft
Room Comments/Treatments:	See above
Time Period/Length of Audition:	5 months
Other (Power Conditioner etc.):	Ginko Audio Cloud 10 vibration control platform, Blue Circle Music Ring, and PS Audio Ultimate Outlet, power cords by Audience, Blue Circle, PS Audio, RS Cable, Signal Cable, and Voodoo
Type of Audition/Review:	Product Owner
Your System (if other than home audition):	N/A

Product Weakness:	Limited Low Bass
Product Strengths:	Play very well at low volume, imaging, coherency, transparency,and tonal accuracy