Coincident Speaker Technology Troubador loudspeaker Follow-Up Manufacturer's Comment
Follow-Up Manufacturer's Comment
Editor: Thank you for your Follow-Up review of the Coincident Speaker Technology Troubador speakers. This follow-up raises some very serious questions which I would now like to address.
It has always been my impression that before a review appears in print in your magazine, that many weeks of auditioning will be undertaken. After all, a reviewer must meticulously set up the new speakers, taking into account all the vagaries of room interaction, component matching, break-in period, etc. This is a time-consuming and onerous task. That, however, does not describe the procedure that was followed with respect to the Troubador Follow-Up. These speakers were received by your office on December 6, 1995. The copy of the review was faxed to me on December 18. That would leave only one week, or ten days at most, to measure and fully evaluate this loudspeaker. The Troubadors need at least 50 hours of break-in before serious auditioning is fruitful. As well, only one system was used in conjunction with the speakers; moreover, the Levinson No.333 amplifier, rated at 300Wpc at 8 ohms and 600Wpc into 4 ohms, was chosen to power speakers (Troubadors) that can be driven by single-ended triode tube amps. This just does not resemble meticulous component-matching, to say the least.
The perfunctory nature of the Troubador listening sessions must, by its very nature, raise questions about how committed WP and JA were in truly unraveling all that could be gleaned from the Troubadors. There appears to have been very little effort expended on these speakers.
What is of even greater significance is how your measurements are used (or misused). Let us examine the graphs published for the Troubador with loudspeakers reviewed in the November 1995 Stereophile. The main criticism of the sound of the Troubadors dealt with its laid-back presentation, which JA correlated to its low-treble suckout. In fact, in most respects the Troubador measured in exemplary fashion. Fig.3 illustrates that the crossover region between the woofer and tweeter at 2100Hz is down only 2dB. As well, fig.5 shows a spatially averaged in-room response (which is where most humans listen to their loudspeakers) that is (with the exception of a small area between 1800Hz and 2800Hz that is down less than 4dB) one of the flattest you have ever presented in your magazine. Fig.2, for all intents and purposes, reveals that the Troubadors are more time-coherent than virtually every other speaker you have measured.
Let us now examine the graphs published for the Wilson WATT 5, Platinum Solo, and Acoustic Energy AE2 Signature. The aforementioned speakers all received glowing reviews, and range in price from $2497/pair to $9000/pair. First, the spatially averaged responses for the Solos (p.117) reveal a variation in response of 6dB from 60Hz to 3500Hz with an almost 4dB depression between 2200Hz and 3500Hz. This anomaly in the crossover region seems to be much more easily tolerated in a $2500 pair of speakers, as JA states: "...slight lacks of energy in both the lower mids and in the crossover region. The latter will make the speaker sound a little polite..." With regards to the time domain, fig.16 reveals a woofer that is 0.4ms slower in arrival time than the tweeter. In JA's conclusion he mentions other problems (excess midbass bloat, low sensitivity), but the bottom line is nevertheless "Recommended...a great start for a new speaker company."
In the Acoustic Energy review, fig.3 (p.111) shows a spatially averaged in-room response that is down 18dB at 3800Hz! The response does not recover until almost 10kHz. Further, fig.8 shows the tweeter and woofer to be out of phase, and the impulse response to be "overlaid with ultrasonic ringing." In fig.9 it can clearly be seen that "hash is developing in the mid-treble..." Does all this matter much in a speaker costing $5495? Apparently not, since JA sums up by stating that it is "superb-sounding."
The measurements of the WATT 5 tells a similar tale as those presented above. The quasi-anechoic response (fig.4, p.106) shows that the WATT by itself is down 10dB at 50Hz, and between 200-400Hz it is depressed by almost 6dB; and again at 3kHz, it is down 4dB, falling again at 7kHz to -5dB. In the step-response graph (fig.9, p.107), it is clearly revealed that the WATT is not a time-coherent speaker by any means. Conclusion? You guessed it. JA proclaims, "This is excellent performance, correlating with the System 5's grain-free and smoothbut detailedpresentation."
The best has been saved for last. I will direct our attention to the December 1994 issue of Stereophile and the review of the $67,500 Wilson Grand SLAMM, which was awarded the prestigious honor of being named the 1995 component of the year by Stereophile. A perusal of fig.9 (p.125) clearly illustrates the more than 7dB frequency deviation in the upper frequencies. Fig.13 clearly shows that the drivers are not time-aligned, and that the phase response is not linear in the treble (p.126). Perhaps these flaws are not as relevant in the under-$70,000 price point, since the competition is not so intense in this price category.
JA's measurement methodology must also be called into question. Our measurements of the Troubador do not exhibit the degree of suckout as represented by fig.4. Our measurement shows that the response is down 3dB. Moreover, JA reports that his measurements [indicate that the] crossover is a symmetrical 18dB/octave. If this is so, then I must surely be granted a patent forthwith on this design, since I would be the only human capable of fashioning a third-order crossover using only one series capacitor with no components in parallel.
In summing up his feelings about the Troubador, JA states that "Competition in the $1500/pair price region is intense. For a new loudspeaker from a new company to stand any kind of chance, therefore, it needs to be almost without flaw." I must have missed something in my more than 20 years in audio, because I am not aware of any component at any price, let alone $1500, that is without flaw. It may be inferred from the review of the above noted loudspeakers that flaws are much more easily ignored in speakers costing twice to six times the $1500 asking price of the Troubadors. With reviews as unfair and hastily prepared as the one given the Troubador, it is of little wonder that new speakers from new companies devoid of very much influence or financial clout will never be beneficiaries of the same latitude afforded established firms that are somehow more prone to be given a sympathetic ear.
I still have faith in those in the know, including dozens of audiophiles who have purchased our Troubadors, with and without the companion Troubass subwoofers, who believe that these speakers not only represent the best value in high-end audio, but in many performance parameters advance the audio art. I believe your review of the Troubador reveals more about your magazine than it does about my speaker.Israel Blume, Coincident Speaker Technology
I usually do not respond to manufacturers; this is their space to say what they feel is necessary. Unfortunately, however, I must point out that Mr. Blume misrepresents my measurements of the other loudspeakers, which can be seen by looking at the graphs published in the November 1995 issue of Stereophile. He also misrepresents my comments about the measurements. For example, my favorable remarks about the WATT that he quotes were made in connection with the Wilson's speaker's very clean waterfall plot, not the step response.
Regarding my measurements of the Troubador, I check my methodology by measuring reference loudspeakers, such as the Rogers LS3/5A, on a regular basis, as well as comparing my measured responses with those supplied me by manufacturers. I stand by my measurements of the Troubador's performance, particularly as they correlated so well with my auditioning. And, of course, how a product sounds is what matters.
Finally, regarding the quick turnaround of the review process, Mr. Blume's original request was that we audition the revised samples of the Troubador in time to get this Follow-Up into the January '95 issue along with WP's original review. As that didn't prove to be possible, I assumed that publishing the Follow-Up in the next possible issue would be the next best thing. The speakers were broken-in overnight before I performed any serious auditioning and did seemed to have reached a consistent sound quality.John Atkinson