^Oh, the irony!
Showing 50 responses by unsound
tomthiel, I humbly(!) submit that I'm a bit disappointed that you would choose the Benchmark as a reference amp. While probably a very fine amplifier in other circumstances, it seems less than ideal for the task at hand. https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-specifications This rated 100 Watt (which is the minimum power recommendation for many Thiel loudspeakers) amp with it's balanced only inputs is not compatible with Thiel 3.5's, is not spec'd to double down into 4 Ohms, is only spec'd to 3 Ohms where it's only putting out 240 Watts and not to the sub 3 Ohm levels of some Thiel loudspeakers. If one had already purchased Thiel maximum power recommended amps capable of 2400 Watts into 2 Ohms (wall power permitting), I think they might think twice before upgrading to "hot rodded" versions that were not tested the maximum output, never mind only tested into 1/10th of that. After hearing years of complaints from those that have not done their due diligence and used inappropriate amplification and then gone on to disparage the Thiel loudspeakers, I would imagine that setting such an example might be fraught with potential backlash. Most of the Thiel loudspeakers under consideration here are far from new. I submit that amplifiers with much better and more appropriate capabilities from their own era can be found at comparable prices. |
tomthiel, I understand and appreciate your points. Please forgive me if I am belaboring the point. Although I would consider a modification that would allow bi-amping with my Thiel 3.5's, I suspect that might be due to the unique qualities of the 3.5's with their 4 Ohm nominal/minimum rating with not dropping below 5 Ohm independent testing, that opens the choices of appropriate multiple amplifiers at more reasonable costs, and of course as a way to restrict the influence the eq which applies to a few other Thiel loudspeakers as well. The special cabling required to make the Benchmark work with the eq's is not typical of how end users make connections. Some might be apprehensive to invest in custom cables that will have such limited alternate use. As such many might disqualify the Benchmark. I would think amps that have more universal appeal with all Thiel loudspeakers might be more advantageous. I think the idea to adapt Thiel's with more challenging impedances with bi-amping with modern amplification certainly has merit, especially considering what I suspect is a paucity of other options. On some level none of referenced speakers could be considered any thing like new, and I wonder if we should just accept that that ship has sailed, and just deal with it. Though appropriate amplifier choices might be limited, they exist and are often readably available. At comparable cost's; would two perhaps less capable modern amps be a better value than one capable one? Mixing amps can become problematic on it's own, doing so with first order cross-overs could make it even more complicated. |
I don't think one has to forgo classic Thiel virtues to attract the HT crowd. The concentric drivers lend themselves to it.The more recent models might be adapted to the more recent HT formats. Imagine another concentric driver mounted on top of the 3.7's dome? Some of the most expensive budgets spent on sound is by Hollywood. I believe one of the reasons HT hasn't attracted that many audiophiles ( expense aside) is the fact that most of them realize that properly placing two channels is challenging enough adding another 3 to 5 or more is daunting, if not impossible. I've touched upon this before, but let me bring it up again. If like Thiel the objective is to get everything off the recording as accurately as possible to the listener, no matter how much attention is paid to the system chain the room itself will ultimately impose the biggest hurdles. One way to help ameliorate the problem is with DSP. I suspect that one of the problems with using DSP in the past is that direct sound from the loudspeaker to the listener and the reflected sound from the loudspeaker to the room to the listener has been convoluted. While is it has been estimated that 80% of the sound one typically hears is room reflected (and therefore corrupted), we know that given sufficient time delay (estimates vary from about 5-8 milliseconds, which loudspeakers placed well away from the walls will provide) listeners ear/brains will prioritize the initial direct sound from the loudspeakers over that of the reverberated room influenced sound. That might(?) be fine for symmetrically placed two channel systems, but such symmetry might well be impossible in typical listening environments for multi-channel (and perhaps preferably so for other reasons) but what was once not much filtering/processing on the ear brain has now become greater in amount and more complex from varying room influences. The problem with DSP in typical room set up is that when correcting for the secondary distorted room influence, one ends up correcting the primary direct sound from loudspeaker sound as well. That can become quite unnatural to the listener and especially more so to those listeners not in the sweet spot! Keep in mind that many recordings already have their original room influence on the recording, now with typical loudspeaker setup we're adding/superimposing more. That might be best be described as distortion. And with HT/multichannel setups distortions that varies from channel position. That's a lot of ear/brain filtering/processing, which might become fatiguing. One way to offset this myriad of convolutions is to minimize them. If the loudspeakers baffle is very close to room walls, then direct sound and reflected sound become more of one, and then the DSP room corrected sound and the reflected sound become more of one and the same, with no or little imperceptible timing issues. The advantages of such loudspeaker placement becomes more evident in multichannel and HT, especially so now that flat screen monitors/screens are fairly standard with their lack (or close to it) of projecting boxes that previously added side reflections. Placing five to seven channels 3-5 feet will into the listening room with 16-20 feet across from themselves (which would provide 8-10 feet from loudspeaker to listener) would require huge rooms (and perhaps a bevy of potential tripping speaker cables) not readily available to the typical consumers. Obviously having the loudspeakers close to the room walls could have decorating advantages that can't be undervalued in the marketplace. With such wall placement, perhaps less labor and money(!) might be placed on cabinet beauty. The downside might be an increase in baffle area to compensate for box volume losses. I have some ideas for such a baffle box, but I've probably taken up to much space already. Still, I suspect that such box reduction costs might be somewhat passed on to the consumer for ultimate multichannel affordability and commercial competitiveness. On some level Thiel has been doing just this for years and with great advantage with their concentric drivers(!), think Powerpoint, Dewdrop, etc.., just without the DSP possibilities.
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Oblgny, efficiency is not necessarily the same as sensitivity, and 2.87 Volts is not necessarily the same as 1 Watt. The 3.5’s depending on vintage were rated as 88-89 dB @ 2.87 V. in to 8 Ohms. That does not account for for the 4 Ohm nominal/minimum impedance rating (though not dropping below 5 Ohms in independent testing ). Suffice to say one could round down to a 85-86 dB sensitivity into actual load. The same holds true for the 3.7’s, only more so as the impedance drops even further. If you consider the actual impedance load the more relevant sensitivity drops accordingly. This is why the power levels into lower impedances need to increase as much as they do. |
There’s been a lot of recent talk about using Bryston amps with Thiel’s here recently. I am not the only one who has touched upon this more than once before, but I guess for some slogging through all the posts on this thread might be daunting. There was a time with the earlier Thiel’s that Bryston was as easy recommendation to make. A company with a long tradition of well made products, with one of the best warranties in the business, respected by both audiophiles and pros alike. Heck, the 3B is still one of my favorites. But... the more recent Thiel’s with sub 4 Ohm impedances aren’t quite as good a match. If one is considering purchasing Bryston amplification for any of the sub 4 Ohm Thiels it behooves you to read the following: https://www.stereophile.com/content/bryston-4b-power-amplifier-measurements https://www.stereophile.com/content/bryston-3b-st-power-amplifier-measurements https://www.stereophile.com/content/bryston-7b-sstsup2sup-monoblock-power-amplifier-measurements We can see that only the biggest 7b mono’s really have a proper 2 Ohm power delivery window to deal with the more recent Thiel’s. Even then it 690 Watts into 2 ohms is equivalent to a 172.5 Watt amp that could truly double down. With the latest Thiel’s impedance load one would be paying for 400 or so of unused Watts per channel. |
rosami, while there has been some incremental improvement (IMHO more hype than substance) over the years in speaker design, I still think the real value is with some of the older stuff. Some of the great designers, like Jim Thiel, John Dunlavy, Peter Walker, etc., have past, and there hasn't been a stampede of newer one's jumping to take their unique places. If you like Thiel's you might want to check out offerings from Duntech, Green Mountain, and Vandersteen. I suspect the next generation of speaker design on the horizon might be a bit different with more internal DSP functions. Time will tell. |
Prof, "...most audiophiles..." aren’t running steady close to 2 Ohm loads, or in my case a steady 4 Ohm load with a 12 dB bass boost eq (albeit with an 8 Ohm impedance bump up at that region). What might seem like copious power into 2 Ohms when compared to 8 Ohms; really isn’t. It’s not all about sheer volume levels, but rather about ideal operating conditions. |
tomthiel brings up a good point about "sweet spot" or best value. For instance my previous declaration in favor of the Bryston 3B (within appropriate matching with older Thiels) was based upon such a criterion. It's not necessarily one the best sounding amps, but at it's price point it performed quite admirably for the task at hand at the time. Which is quite an accomplishment! It's a lot easier to make a cost no object good sounding (and unfortunately enough examples of the over priced / under performers exist as well) kit, than one that performs nearly as well for quite a bit less. |
Tom tomthiel. HAPPY BIRTHDAY! I think you nailed it regarding time. I’ve come to believe that like other things in audio some people are more sensitive to such things. And even if statistical data suggests that many if not most don’t seem to appreciate it; for the many that do, do it consistently and deeply. I also hope you realize that your time on this mass hurling through space, has brought about deep and enduring joy for many. I’m sure all here wish for you to be around for many more birthdays. Thank you. |
^...Or a treble roll off. Which is why I think the smaller models sometimes can sound a bit tilted up compared to some of the competition. The more full range (and having the room to properly accommodate that can not be over emphasized) Thiel's are less likely (when properly amplified and set up) to sound bright. |
Was someone's feelings hurt? It seems as though more posts have been deleted. If that's the way this thread is going to go, I'm not sure I can continue here with that type of censorship. We have already lost valuable contributors here for the same reason. I don't really want to split this up , but perhaps we might need to move this dialogue (!) to another thread where the discourse has greater freedom? |
@ctsooner , @erik_squires , et al, Please see the post by the late Roy Johnson dated 05-09-2005, 12th paragraph: https://forum.audiogon.com/discussions/first-order-crossovers-pros-and-cons |
https://www.stereophile.com/content/ayre-acoustics-v-3-power-amplifier-measurements-part-2 https://www.stereophile.com/content/ayre-acoustics-ax-5-integrated-amplifier ...Probably why Ayre does not spec their amps to 2 Ohms. |
I’m guessing you meant un-equalized CS 1.2’s? Checking the eq is a good suggestion. I’ve never had a problem with mine, but in the last 30 years there have been some reports of eq issues. Your available power is just about the minimum suggested for the 3.5’s, but it is a small (and not ideally proportioned) room, and that might the reason for the limited bass response. I’ll hazard a guess and say the 40 Hz setting will probably work better in your room. |
@tmsrdg, It was a long time ago, but when I lived in NYC one my favorite dealers carried amongst others both Spectral and Thiel. They often rotated both in and out. I think this was up to the 2 2’s and 5’s time period, but pre co-ax. My recollection was that the combination demonstrated both of their attributes, but the Spectral while capable of handling the low impedance of say the CS 5’s, was happier with the above 4 Ohm and above Thiel’s. The Spectrals were admirably lighting fast, very detailed, smooth, with no electronic smear what so ever. Ultimately I found them a bit thin, threadbare and bleached. I can imagine them having their admirers though. The Spectral’s were said to be rather particular about matching pre’s and speaker cables, with their own pre and MIT cables being very strongly recommended! Hope this helps. |
Large threads like this are good for maintaining a specific community. On the other hand, large threads like this can become cumbersome to sort through for very specific considerations. With that said, let me again point out, as I oft have; that over generalized recommendations about amp compatibility with Thiel’s can be misleading. In past times, Thiel recommended amp brands for the speakers made at the time. Later models have different powering needs. Those previous recommendations may no longer apply to later model Thiel’s. I’d also suggest caution in reading too much into what Thiel or any other manufacturer used at shows. One might assume that accompanying gear was specifically hand selected by the manufacturer to demonstrate the utmost capabilities of their own gear. The truth often is; that rather than transporting crates of heavy equipment over great distances, the manufacturers depend on local dealers to assist in providing gear for demonstrations. Those local dealers might have their own convenience or agenda at the top of their priority list. Not to pick on any specific brands, but the some of the often recommended amps from companies such as Ayre, Bryston, Pass, PS Audio, etc. might work wonderfully with some Thiel’s, but are not designed or spec’d by those very manufactures, (independent testing, such as those found in Stereophile will also confirm this) for the sub 4 Ohm loads of some later model Thiel’s. Be wary of dealers selling(!) you otherwise. |
@ronkent, I've posted much of this before on this thread, but here it is again: https://www.stereophile.com/content/thiel-cs24-loudspeaker-measurements Notice that the Thiel CS 2.4's spend the vast majority of their time "..significantly below 4 Ohms between 100 Hz and 50Khz.." with a challenging phase angle to boot. https://www.psaudio.com/products/bhk-signature-amplifier/#tab-specs Notice that PS Audio only indicates that at 2 Ohms the BHK 250 is only "Stable for musical transients". That's a rather low bar for these speakers, basically saying that the amp won't blow up if briefly exposed to 2 Ohm loads. No mention of how much power and for how long it can deliver that power into that load. Well, never mind "...musical transients" we can see from above that the Theil CS 2.4's practically live in that impedance region. Now the BHK 300 seem to be spec'd much more up to the task, though the amps are not quite doubling down to 2 Ohms. So one is paying for some unused power over the vast majority of the time. Still this would appear to be a pretty good match. Notice the last sentence: "....,though it will perform best with speakers having and impedance of 4 Ohms and above.-John Atkinson I have no doubt that these are fine amplifiers, and that they can provide much enjoyment, but at nearly $15K I think one could find amplification better suited to the demands of speakers like the Thiel CS 2.4's I don't mean to pick on PS audio (FWIW, I'm quite impressed with their digital products, though they are rather expensive), similar results can be found on many of the other highly touted amplifiers. |
@Beetlemania, Let me say that off the top of my head I can't think of any amp manufacturer that's complete line is ideal for all Thiel's. Yes, it's somewhat complicated, but most of the difficult leg work has been done and the results are often readily available. With such information it's not too difficult to get a fairly good idea of what's going on with such interactions. As for the impressions of others? Well, I'm cautious about that. I have no idea what some of these strangers experience might be. We've had posters repeatedly state that particular amplifiers were "high current" when they weren't. At least not by my definition of that. Subjective impressions are important. After all in the end, one should like what they're buying. But, I sometimes wonder why they do. I have occasionally offered my own subjective opinions, with the caveat that others might disagree. But, I do try to offer some objective perspective too. I prefer to make decisions based on what I know, not on what I don't. Let's look at some of the examples that you cited: https://www.stereophile.com/content/thiel-cs16-loudspeaker-measurements Notice that impedance stays below the rated 4 Ohm load of the amplifier referenced most of the time, and with a phase angle that might be stressful. https://www.stereophile.com/content/ayre-ax-7-integrated-amplifier-measurements re: distortion: …."However, it more than doubled each time the impedance was halved, implying that low-impedance speakers are best avoided."... ..."Considering the fact that Ayre's Charlie Hansen eschews negative feedback, the AX-7 still provides excellent linearity and basically good measured performance, provided the amplifier isn't asked to drive speakers with an impedance that drops below 4 Ohms."... *To be fair we might want to take the above measurements with a grain of salt, as the reviewer as some point replaced the fuse with a different from recommended value. ______________________________________________________ https://www.stereophile.com/content/thiel-cs24-loudspeaker-measurements ".....it's impedance plot (fig.1) indicates that the CS 2.4 demands a lot of current from amplifiers. Not only does its impedance drop to 2.7 Ohms at 600Hz, but it stays significantly below 4 Ohms between 100 Hz and 50kHz, and there is a difficult combination of 4.5 ohms magnitude and -45degrees electrical phase angle at 80 Hz.".... https://www.stereophile.com/content/ayre-acoustics-ax-5-integrated-amplifier-measurements …." into 2 Ohms the (not shown), the Ayre clipped at 220 Watts with one channel driven, with a higher level of distortion at lower powers." Quite a bit less than the 500 Watts per channel of an amp capable of doubling down an down again from it's 125 Watts at 8 Ohm rating. I don't think it takes a genius to figure out why this stereo amp was only tested into 1 channel at 2 Ohms. ______________________________________________________ https://www.stereophile.com/content/thiel-cs72-loudspeaker-measurements "Like most Jim Thiel designs, the CS7.2 features quite a low impedance over most of the audio band (fig.1), with a magnitude dropping below 2.7 Ohms above 8 kHz and ranging between 2.9 Ohms and 4.2 Ohms between 60 Hz and 8 kHz." https://www.stereophile.com/content/ayre-v-1-power-amplifier-measurements …"While the amplifier easily meets specified power into 8 Ohms, it didn't do so into 4 Ohms, though the line voltage was slightly lower than normal."...…."In order to test the amplifier using continuous test signals into 2 Ohms, we had to replace - at Ayre's recommendation - the V-1's internal 10 amp resistor-fuses 15 amp versions". I'm willing to make concessions due to the line voltage issue. Note that this stereo amps 2 Ohm output was again only measured into 1 channel and put out 555.5 Watts into that one channel, rather than outputting the 800 Watts of a similarly rated 8 Ohm power amp that can double down and double down again. I Couldn't find anything on the Ayre V-5. _____________________________________________________ https://www.stereophile.com/content/thiel-cs37-loudspeaker-measurements ….".....the 3.7's impedance remains between 2 and 3 Ohms over much of the audio band (fig.1), and that there is a demanding combination of 3.8 Ohms and -40degrees capacitive phase angle at 60Hz. Thiel specifies the impedance nominally at 4 Ohms, with a minimum of 2.8 Ohms. I actually found the impedance to 2.4 Ohms at 125Hz. The difference being academic, either mandating the use of an amplifier that has no problems delivering high currents." 35 Watt Fischer. Really? "It didn't acquit itself too badly." I'd rather hear that my blind date had a nice personality. _______________________________________________________ https://www.stereophile.com/content/thiel-cs5-loudspeaker-measurements Yada, yada, yada. See above, I'm sure your get the point. _____________________________________________________ I'm confident that you are aware of most of the following, but for the sake of those that might not. Remember sensitivity predictably decreases as impedance decreases. That power requirements for increased volume levels is exponential. What might appear to outrageous amounts of Watts into lower impedances, really isn't. Furthermore, the inability to increase power as such, causes more distortion from the amp (if not down right self destruction), and at higher volume levels can effect frequency response deviations from the loudspeakers, and perhaps even timber perception for the listener. It's not all about volume levels, but more about amplifier linearity and minimizing distortions. And even actually protecting the loudspeakers from damage. It behooves one to at least listen to an amplifier truly capable of handling the actual load of a loudspeaker to get a baseline, before deciding to accept otherwise preferred distortion artifacts. Otherwise one might find themselves as though they were haphazardly running through a maze blindfolded. Some Thiel's are somewhat unique and require more discriminating amplifier choices. Good listening my audiophile friends. |
@ronkent, I like and respect Paul. There is very little I disagree with him about, such as the importance of time coherence. If he did ask why a BHK might be disqualified for use with a given Thiel, then I have to question whether or not he actually read my post. I don't usually like to speak for those that can speak for themselves, but this was addressed to me, and I might be doing TomThiel a diplomatic favor in this case; if you were to search through this thread, you might find from himself regarding, yes, the inquiry about BHK amps with Thiel's, and further along in the thread a caution about Thiel impedance loads and the " 2 Ohm Stable for musical transients" rating. |
@Beetlemania, That would depend on the loudspeakers and room. 85 dB is rather a low bar. Much music is intended for much greater peaks. At this level I think we can reasonably expect a lot more. I would really like to be able to achieve about 105 dB peaks on symphonic crescendos. Since ultimate volume levels are not that high a priority for me, I settle for less. I think that compromise might be the weakest part of my system, but I’m OK with it. Though I haven’t measured it, I suspect I can achieve somewhere between 95 dB and 100 dB peaks. But, that’s not the point. It’s about providing the least distorted, clean power into the actual load at hand. If I recall correctly, your running Thiel CS 2.4’s? If that’s the case, I’d suggest a minimum of 400 Watts into 2 Ohms per channel. Preferably twice that. That might sound like an outrageous amount of Watts, but that minimum can be had with a true high current 100 Watt rated into 8 Ohms per channel amplifier. If your enjoying your system with less than that, just imagine what it might sound with appropriate power into the actual impedance of your own CS 2.4s! As to why JA might suggest a "... good 4 Ohm - rated amp..." I would offer because sub 4 Ohm loads are unusual, amps are rarely rated as such, perhaps due to the fact that way back when tubes ruled the day, very,very few amps had less than a 4 Ohm tap. As for the numbers, if they can provide guidance, why not? Would you prefer that I just shoot off !@#$ from my hip or some other part of my anatomy? Despite all the guru mysticism marketing BS in audio, these are still exercises in engineering. |
@Beetlemania. Once again, it’s not about ultimate volume levels, but rather the ability to provide the power into the actual impedance loads of the loudspeakers. I never meant to single out anyone in particular. Just the opposite, I’m suggesting that some of the amp recommendations made here by others weren’t necessarily the best general recommendations for many Thiel’s. It just so happened that I ended up following up to those individuals that responded to my post. The power levels I suggested were actually based upon Thiel’s recommendations. Jim Thiel told me himself that Thiel’s power recommendations were based upon standard 8 Ohm power recommendations, with the assumption that the amps could double down as needed. He offered that for example that if using say a Thiel with a 4 Ohm rating, and one wanted use a tube amp (incapable of doubling down) then one should double the power recommendations appropriately. As you can see from the links in my previous posts, many of the amps frequently reccomended here, struggle to do so into lower impedances. As impedances drop so do sensitivitities. 400 Watts into 2 Ohms won’t provide much more volume output than 100 Watts into 8 Ohms. I don’t think many would find 100 Watts an outrageous number of Watts with an 8 Ohm speaker. |
Perhaps some are confused about the impedance/sensitivity relationship. Thiel like many other loudspeaker companies rates their sensitivity as 2.83V* / 1 M. This can be confusing. With each halving of impedance one can subtract about 3 dB of sensitivity. As evidenced in the "Description" in this link: https://www.stereophile.com/content/thiel-cs5-loudspeaker-specifications-0 *Not 1 Watt |
@ronkent, I too have been steadily using Thiels for over 30 years. I never considered myself a "headbanger", and as I've said before, ultimate volume levels is a low priority for me. Still, it's a relevant aspect and I'm confident that Jim Thiel gave considered effort addressing it. As one moves up the Thiel range, one of the advantages is that the speakers become more capable of moving more air, with greater dynamic range and ultimate volume levels. Let's look at what Larry Archibald former editor and former owner of Stereophile had to write about Thiel's and dynamic range.: https://www.stereophile.com/content/thiel-cs12-loudspeaker-page-2 https://www.stereophile.com/content/thiel-cs2-loudspeaker-larry-archibald-page-2 https://www.stereophile.com/content/thiel-cs35-loudspeaker-page-2 https://www.stereophile.com/content/thiel-cs5-loudspeaker-page-3-0 In some cases more recent models seemed to trade some bass response for greater loudness capabilities. Thiel's might not have the ultimate volume levels of some of the big horns, but, neither are they limited, like so many panels are. They might not be the best in any single category, but IMHO they can offer very good to excellent performance across the board in every category, save perhaps for generosity in amplifier compatibility. |