The most interesting German Physiks speaker line (I'd love to hear a pair!) use interesting cabinets, damping and drivers(!). German Physiks Carbon Mk IV Loudspeakers — German Physiks (german-physiks.com) |
I think the old Walsh and new DDD mostly bending wave drivers (there seems to some combined pistonic motion too) might prove that pistonic motion is not a requirement for time and phase accuracy. The Quad ESL ‘63 is another work around that would appear to dispel the notion of a pistonic motion requirement for time and phase accuracy, Of the above mentioned examples, It should be noted that none use 1st order cross-overs either. Though to be fair I think only the limited production Walsh A could be considered full range, and that model seemed to be plagued with reliability concerns. HHR Exotics claims their updated version of the Walsh drivers have addressed many of the concerns of the original Walsh drivers. |
@tomthiel, As I understand it, though the Walsh driver is conical, the bending wave travels faster than the speed of sound, thus being able to produce step and square wave response indicating time preservation. The omnidirectional dispersion, while perhaps tricky for small room placement, is capable of charging the room rather uniformly. The original Walsh drivers were a difficult balance in that they required quite a bit of power yet could be damaged if overdriven. Modern versions claim to alleviate these issues, though extreme SLP’s still seem to be the forte’ of other designs, distribution seems somewhat limited, and they are not inexpensive. I have not heard any of these type of drivers in decades. I would welcome the opportunity! |
Some like McIntosh with Thiel. McIntosh succeeds in accomplishing their design goals, they are well made, and bench test well, they hold their value as well or better than most of the competition, they will likely have parts and well qualified techs available for some time to come, their consistent, tasteful, even iconic styling will probably go into the future making visual aesthetically pleasing compatible future McIntosh purchases probable. With that said, I can't for the life of me understand why they still use autoformers in their ss amps. Perhaps it made sense with their background in the early 60's when transistors were anything but reliable. But easily for the past 40 years that has not at all been a concern. That they add the autoformers and all the extra taps necessitated by them, as well as the poorly functioning meters only adds technical compromise and expense. The MC462's 2 Ohm Class AB output is the equivalent to that of a 113 Watt amp without autoformers that can properly double down to 2 Ohms. The MC 462 seems rather expensive for use with the Thiel CS 2.4's The only other example of a ss amp I'm aware of that used an autoformer was a limited edition run of a First Watt amp made for unique application, and in that case the autoformer was used on the input rather than the output as McIntosh does. For the McIntosh autoformers to work ideally they need to be used on an exceptionally linear impedance load. Which is not typical. Look at the Thiel CS 2.4's impedance graph here: Thiel CS2.4 loudspeaker Measurements | Stereophile.com Notice that the impedance rises to 15 Ohms at 60 Hz, typically a demanding area. Meanwhile the MC462 is recommended to be used with the tap that corresponds to the speakers lowest impedance. Which in the case of the Thiel CS 2.4 is close to 2 Ohms, and stays there most of the time. McIntosh Laboratory MC462 power amplifier Measurements | Stereophile.com While I appreciate the MC462's spec'd sensitivities for both single ended and balanced inputs, which would accommodate direct connection to many self volume controlled DAC's, the measurements don't live up to the specs, and vary with the tap used. Furthermore, the input impedance is not the most cooperative for that economical advantage. FWIW, subjectively I never appreciated the Mac house sound. To my ears they lack dynamics and dimensionality. YMMV |
@thoft, Thiel CS3.6 loudspeaker Measurements | Stereophile.com Thiel CS7.2 loudspeaker Measurements | Stereophile.com Actually, as you can see from the above measurements, they are a very similar load to amplifiers. The 7's are a much better speaker. One of Jim's best. That's a great price for a speaker of this quality! The 4 driver 7's ease at playing deeper bass with greater dynamic range will probably have users pushing their amps harder to appreciate that over the 3 driver 3.6's which will will begin to demonstrate strain much earlier on. Both of these speakers bass output is most likely to overwhelm a 10' X 13' room. A room of those dimensions will probably be better served by a 1 series Thiel. |
^Nice amps for Thiels. Unusually most users report better results through the single ended RCA inputs rather the balanced XLR inputs with these amps. I’d caution you about using these amps in bridged mono configuration with your Thiel’s. Typically bridged amps don’t do well into low impedances. A better alternative would be to have your Thiel’s modified so that each would have dual binding post pairs and have each amp run a channel to the each of the binding posts of each speaker. In this configuration each amp would receive either two left channel or two right channel inputs respectively. A pre with dual stereo pre outs helps facilitate this. I would suggest avoiding a pre that leans to the dark side or has a rolled off treble with these amps, “liquid” presentation would be a plus. These are fairly sensitive amps, be careful of very high output pres, or you might have limited volume control range. |
^For those that seem to appreciate the difference between coherent and non-coherent speakers, I think it’s a combination of conscious and unconscious appreciation. This might be especially true for the superior transient response, which is consciously self evident, but perhaps unconsciously appreciated as offering perceived superior imaging as well. |
^It’s not practical to expect Thiel or any other loudspeaker manufacturers to build speakers that come with their own dedicated rooms. I’ve suggested before that perhaps flat profile coincidental drivers with compensation for flush wall mounting coupled with DSP could be a solution to the dilemma you’ve pointed out. There might be Doppler effect issues that will need to be addressed with the coincidental drivers, Yes, technology moves on, sometimes applicable progress takes time to catch up. |
If I may add to @tomthiel ‘s comments. I think that it’s important to remember that when we read of empirical statistical reports results, we often don’t get the whole picture. The results might suggest that on average most people don’t seem to perceive time and phase coherence or the lack there of. That doesn’t mean that all didn’t. For some reason, some are more sensitive to this than others. And conversely those others might be more sensitive to other aspects of sound. If I learned anything from this hobby is that while we have remarkably similar hearing; we listen quite differently. For example, one of our regular thread contributors @prof has reported his impressions of various loudspeakers here on Audiogon, and I couldn’t possibly agree more with him on every single occasion, His words could be mine; word for word. Yet, when it comes to amplifier preferences, and to a lesser degree on speaker/listener location, we are worlds apart. For what ever reason we tend to have very definite even though subtlety different impressions of listening impressions. Which is why I try and present as much objective evidence as I can when posting. |
@sdecker, while those panel speakers might be somewhat better at time and phase coherence than most typical speakers, they don’t really qualify, as it still takes time to cross the surface of those drivers. The Quad ESL’63 are a notable exception with their time coherent concentric rings. The somewhat more typical dynamic single drivers, again can be better, but still usually don’t qualify. It takes a concerted effort to achieve true time coherence that can be verified with an appropriate step response. I do not usually share your appreciation for headphones. The in your head presentation just sounds weird to me. I can appreciate that for some studio productions made without musicians present, that headphone listening might indeed be a more accurate reproduction of the music’s genesis. Such listening for me is very infrequent. |
@thoft, the 3.6’s are probably already too big for your room, I think the 7’s (as good as they are) output, will overwhelm your room. If the 3.6’s are in any kind of decent shape, should garner well over that figure on the open market. This all seems akin to one living in an apartment, struggling to feed themselves; considering buying a horse as a house pet. |
@sdecker , your post got me to thinking past memory. I went back and looked at measurements for the other loudspeaker brands you mentioned. Of the ones I could find such measurements for, one brand surprised me for it's step response, though there were real problems elsewhere, the time response for the Zu's were better than I recalled. |
@bellesfan, If I may be so bold to recommend (and I offer this without knowing all room dimensions) that you try moving you speakers 3’ in so that the centers are 10’ apart, and moving the speakers further out from the wall behind the speakers so that the speakers are 10’ from your listening position. This could remove more of the sound from the room, providing a greater degree of direct listening, while maintaining ideal driver integration. |
@jchussey , The Thiel's are a complete speaker "system". The baffle angle was determined by the depth of the specific drivers chosen at the time. The crossovers were designed to compensate for the specific driver anomalies used at the time. And, time is the operative word here, in that is the very thing that most separates Thiel's from the very vast majority of other loudspeakers; their almost unique ability to preserve accurate time. Any changes without further very specific modifications will undermine that quality. While I was aware of the scarcity of genuine Thiel CS 3.5 midrange drivers, I was unaware that that extended to early CS 3 tweeters. Does Rob at Coherent Source have any? Perhaps @tomthiel can comment if something like this might be a suitable replacement: Thiel CS2 Tweeter in original Thiel box Dynaudio D-28AF - Speakers (highperformancestereo.com) and there's this: THIEL CS3 ELECTRIC BASS EQUALIZER | eBay These are listed as pickup only, but as this pair's woofers need replacement, I'd hate to see two pairs of these classic speakers ruined if one pair could be sacrificed to save the other pair. Perhaps the seller would consider parting out: Thiel CS3 80s Real Wood | Dan's Shop | Reverb Though there's something to be said about modifying these old classics to be improved, but I find it an anathema to see these old beauties bastardized Willy Nilly to undermine them to be compromised versions of what they once were. Good luck with the project, I do hope you can save them. |
@jchussey , I didn't realize that the original tweeters were also in short supply. I'm so sorry to read that you had such difficulties with "High Performance Stereo". Your reporting of it is a service to us all. I'm confident that your warning will be heeded. |
@beetlemania , those are random peaks into a load that doesn't drop below 4 Ohms. My amp is capable of 500 Watts per channel continuous into 4 Ohms and double that for up to a couple of minutes. All within Thiel's recommendation. |
^While not specifically calling out the Coda, I often suggest caution when reading the meters on consumer gear. Despite their not inconsiderable expense, they are almost never calibrated, and more often than not serve to misinform rather than to inform. I'll hazard a guess that the digital meters on some of the newer ultra-expensive gear might be more accurate. |
@yyzsantabarbara , I think the first graph on each of the respective links might explain what's going on: KEF LS50 Anniversary Model loudspeaker Measurements | Stereophile.com Thiel CS3.7 loudspeaker Measurements | Stereophile.com Jim Thiel seemed to be rather cognizant of the effects of a steady vs. a variable impedance load on amplifiers. As much as a low impedance is tough on amps, amps don't typically care for a varying load, especially tube amps. A variable load can exacerbate the mechanical / damping issues of analog meters as well. @Imhififan, at these impedance loads the rated sensitivities can be misleading.
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@tomthiel, et al, Saw this on another site: Renovating Thiel CS3.5 Speakers | Page 2 | Audio Science Review (ASR) Forum Post #27 Is there newfound hope? |
@tomthiel, I was really trying to specifically point out Post #27 where the poster found a way to resuscitate a midrange driver that might have otherwise been discarded. There may be hope for those that might have otherwise given up in the meantime while your project comes to fruition. The last paragraph of your last post succinctly describes what made those early CS 3 series so great (and the above 4 Ohm load!). That you are trying to make them even better is truly exciting! |
@arvincastro , Good luck, enjoy! |
^Interesting. For $55K the Humboldt's specs don't impress, especially for a load like the Thiel CS 3.7's. The Humboldt is rated for 320 Watts into 8 Ohms / doesn't come close to doubling down with 460 Watts into 4 Ohms and is not spec'd into 2 Ohms at all. The less than half the price Diablo on the other hand is rated for 300 into 8 Ohms doubles down to a greater and more linear response of 600 Watts into 4 Ohms (the CS 3.7's actual nominal load) and 950 into 2 Ohms. With the CS 3.7's 4 Ohm nominal / measured 2.4 Ohm minimum load and recommended power of 100 - 600 Watts (into an 8 Ohm load, with the understanding that the amp could double down as necessary) the Diablo appears to be better suited. For much less than $55K one could easily find separates with more apparent appropriate specs. |
^Thiel measured their speakers from a distance of 3 meters (approximately 10’), and a minimum of 8’ is required for driver integration and time alignment, aimed straight ahead. If I recall correctly, the 3 meter distance would have a convergence of 22 degrees behind the listener. As space allowed, close to an equilateral triangle for placement was recommended. So, in a room with available side wall space (at least 3’ and preferably 5’ or more) closer to 10’ apart center to center. As you have more than 5’ to side walls, closer to 10’ might work and provide for a bigger soundstage. The distance to listener is another variable to consider. If placed 10’ apart (center to center) and you have less than 10’ between listener and speaker, a bit of toe in might be needed. Toe in can be tricky, just a little bit goes a long way. Too much toe in, and you can shrink soundstage and perhaps even worse, introduce brightness. Another consideration would be the distance of woofer centers to front, rear and sidewalls, and though obviously less controllable, floor and ceiling. The ratios of which can be important for smoothing bass frequency. Simply put; it might be best not to have even multiples or divisibles of any of those distances. FWIW, as I set up my Thiels, my room affords similar wide space between speakers and sidewalls, but regrettably doesn’t offer quite the ideal distance of listener to speaker. So, I set up mine 10’ apart (center to center), 7.5’ from center to sidewalls, cabinet backs 3’ from nearest wall, and a speaker to listener distance of 8.5’. with 2.5 degrees of toe in. If your room is similar to mine in that the back wall is close to the listener, I can’t emphasize how important some absorptive room treatment behind the listener can be! Every room is different. Use the figures as a starting point and customize as necessary.
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@Thieliste, Same here, long wall. I personally prefer long wall placement. I find imaging and bass response often improves with such a layout. But again, absorption directly behind the listener is required to avoid comb filtering. Even if it's just a temporary item used only during listening sessions. Also, pulling the speakers well out (>3') from the wall behind them will help with clarity. If using spikes, I suggest removing them while experimenting. Replace them when ideal positioning is established. 9' could be ideal, but don't be afraid to try wider. Especially with such available space from side walls. Just a slight tick of just a couple of degrees of toe in could easily compensate for the foreshortened distance of listener from loudspeakers. It might really open up the soundstage. Keep in mind the center of the woofer's relationships to the various boundaries. Experiment! Test recordings can speed up the process. Good luck! |
@johnhh, Please note the following: Thiel CS1.5 Owner's Information (Page 5 of 6) | ManualsLib CAP-101 - Integrated Amplifier - Classé Audio Support (classeaudio.com) Classé CAP-100 integrated amplifier Measurements | Stereophile.com The CS 1.5's is a honey of a speaker for a small room. They still need to be, like the bigger models in the line up, placed somewhat out from surrounding walls and still be at least 8' from the listening position. As a design decision, that makes some academic sense, but I question the practicality of such placement requirements in the typical small spaces in which they will be used. In any event, they should work quite nicely indeed in your smaller 12 X 15 room, but for the 24 X 24 room, a larger, even if older model Thiel might be more appropriate. In addition the power requirements might be quite different. Note that the CS 1.5's drop to about 3 Ohms, while not brutal, still demanding. Not typically where intergrateds thrive. While there are a few very expensive exceptions, many intergrateds are not capable of doubling down with impedance like their separates counterparts. Additionally, intergrateds tend to drop their more linear Class A output bias into lower impedance loads at a faster rate than their separates counterparts. It is a mistake to assume that intergrateds are just compacted versions of their separates counterparts. Thiel recommended quality amps rated between 50 and 150 Watts per channel into 8 Ohms for the CS 1.5's, with the understanding that these quality amps could double down into impedances. That would be about 150 to 450 Watts into the minimum 3 Ohm load of the Thiel CS 1.5's. It's not likely one will find a 3 Ohm ratings, but the amplifiers capable of doubling down into 2 Ohms will most likely make claim to it in their specs. If it's not there, they're probably not capable of it. To be safe; look for amps that have ratings of between 200 and 600 Watts into 2 Ohms. Room size and sound volume will ultimately determine power requirements. For the your small 12 X 15 room the lower power figures will probably suffice, but for your larger 24 X 24 room consideration, more power will probably be desired. Though often promoted by dealers as a good match, the Classe' Cap 101 and Thiel CS 1.5's combination was probably more of a marketing match. After all, the more capable Classe' separates worked well with many of the larger Thiels. While the Classe' Cap 101 is within spitting distance of the minimum suggested power at close to the actual impedance load, we can see from the specs that it appears to be struggling to up power into a 4 Ohm load with just a 40% increase in power from 8 Ohms into 4 Ohms, instead of the desired 100% increase. I think it fair to assume that the expected power increase into the CS 1.5's 3 Ohm load the Cap 101 will be compromised. The above linked measurements of the earlier Classe' Cap 100 shows that it blew a fuse when delivering only 200 of the 400 Watts expected into 2 Ohms when driving only one channel. Put another way; a half the 8 Ohm rated Krell KSA 50* power amp will handle the CS 1.5 impedance load better. Don't be fooled into thinking you might be covered with a "stable into 2 Ohms" disclaimer. That only means the amp won't go into oscillation when presented with a 2 Ohm load. That could mean that the amp just shuts itself off before blowing up. It doesn't suggest how much power, at what linearity, with how much distortion, or how it will actually sound at 2 Ohms. In your 12 X 15 room you might get OK results, but should you want to use the 24 X 24 room you might find the Classe' CAP 101 wanting. * Krell KSA-50 power amplifier Specifications | Stereophile.com |
@dmac67 Consider the resale value of modified gear can often be compromised. As for the compatibility of your Krell 400xi integrated with Thiel 3.6’s: Thiel CS3.6 loudspeaker Specifications | Stereophile.com Thiel CS3.6 loudspeaker Measurements | Stereophile.com Krell KAV-400xi integrated amplifier Specifications | Stereophile.com Krell KAV-400xi integrated amplifier Measurements | Stereophile.com We can see from the above links that the Thiel CS 3.6’s impedance stays well below 4 Ohms most of the time. We can also see from the above links, that unlike some, but not all (!) of the rightfully famous, for their ability to keep on doubling down power into lower impedances, Krell separate power amplifiers, that the Krell 400xi integrated is not rated for sub 4 Ohm loads, nor could it withstand the rigors of measurement testing into such loads. If your interested in Thiel CS 3.6’s, you would do well to consider different amplification. There are only a few, usually expensive, integrateds that are up to the task; some of the Gryphons and the DanDagastino Momentum amongst them. |
