I just scored a sweet pair of CS 2.4SE loudspeakers. Anyone else currently or previously owned this model? Owners of the CS 2.4 or CS 2.7 are free to chime in as well. Thiel are excellent w/ both tubed or solid-state gear!
I'm with bluetone. The first time I heard the 3.5 demo-ed at a local emporium my jaw dropped. I finally picked up a pair in excellent condition seven years ago. Recently I upgraded my amp and preamp with more nice vintage gear. A Classe CA300 amp and Superphon Revelation preamp. My jaw dropped again. The palpability and power are still astounding.
The foam surround on one of the mids has finally given out though - and I am in the same boat as bluetone and many others. I stupidly had only one of the mids rebuilt by Thiel back in o4 and that one is still good.
I’ll be trying the scan-speak 10F/8424G form Madison soon.I’ll first compare it with pink noise, other listening tests and some simple measurements, to the original in the other speaker.If it’s close I’ll put the 10F/8424G in both and work on getting the original 13M 8521 re-foamed. The tough thing about that is finding the right foam surround for it.
Re. harshness etc. As many have noted. These need the right room and the right electronics or they can sound very annoying indeed.Satisfy their requirements and and they are still capable of astounding
I will post again after experimenting and would very much like to hear how bluetone and others have faired in this endeavor.
Rules - that's listening position. Peak capture might register 100dB, unless I'm driving hard to cause distress on purpose.
My listening is almost entirely for data-gathering. My chair is on wheels and my spl meter is velcroed to my thigh. 2' square carpet tiles tell me where I am and where the speakers are. Listening distance is generally 10' to 12' out (10' was design distance.) I find more value in terms of speaker distances from walls, rather than between them. Thiel polar pattern is optimized away from boundaries, and many problems result from early reflections. In a 15' wide space, I would rather have 6' between speakers with 4.5' to side walls, than to have 8' between and only 3.5 aside.
dspr - Rob at Coherent Source Service could check your serial numbers for whether yours were upgraded to the "i" status. The difference was upgraded woofers and possibly an XO tweak to compensate.
For the room bit, I recommend moving them away from the side walls and back wall as far as practical. Just for input, try 5' behind and 3-4' to the sides.
1. regarding Thiel CS 5 versus CS 5i speakers. My pair of Thiels say CS5 on the bottom of the cabinet and I've posted pictures to sell them.
One of the responses to my ad was to tell me that the speakers look like CS 5is because the middle woofer looks different (it has a smaller dust cap) compared to the upper and lower woofers. Does anyone know if this difference in woofers indicates that they are CS 5is?
2. I am also looking for advice on what else to try with my Thiels to make them disappear in the room. I was active on this forum about a year of two ago as I fought my way through amplifiers and DACs to make the Thiels sound good. My McCormack DNA-500 drives them effortless and my Theta ProBasic III DAC got the treble to my liking. I also used room treatments to improve the bass response and absorption to further manage the treble.
However, I could never make them disappear in my room. Logistics force them to be about three feet from the front walls, ten feet from the listening position, ten feet between the speakers, one speaker is within three feet of one sidewall, and there is 15 feet of open space behind me.
By contrast I recently placed a pair of Tyler Acoustics MM5X's, a much smaller speaker, with a 60 WPC CJ tube amp in the same space and they disappeared in the room and have better dynamics. Its like magic compared to the Thiels.
I know the Thiels are a great speaker but want to know if there are any other ideas to try before I complete a sale of them....
Speaking of tubes i also did consider integrated tube amps to drive CS 3.7s, the ones i was looking at are the Allnic T-2000 25th and the VAC Sigma 170i.Both of this integrated could probably do the job at moderate volumes in medium size room.
I never got the accolades given to the Cowboy Junkies "Trinity Sessions" album when I listened to it with all the other semi-decent systems I had. With the CS3.7 I get this album. Rather brilliant recording on the 3.7's.
Hi, y'all. Been away from the thread for awhile, but not from the subject. I'll explain in a minute.
About a year ago, warjarrett ("Sandy") wrote back to Tom and myself about both the Amber amp I had suggested for Thiels, and on the subject of tubes vs transistors in general. Sandy said as the conclusion of the note: "
So my advice is that just about any stereo tube amp, with at least 60 wpc, into the CS3.5 is pure heaven. With solid state, you need to be more careful to audition in advance, and don’t go lower than 100 wpc in power." I now find myself concurring completely.
At the time of Sandy's note I had been thinking about returning to tubes. I had previously driven my first pair of 3.5's with an ARC D90 and later a VTL ST-85. But after many changes to the system I ended up with solid state, and still later substitued the Amber Series 70 amplifiers that both Sandy and I think are well suited for Thiels.
Just after the first of this year, a pristine ST-85 came on the market at a good price and I snapped it up. It sounded great (again) with the 3.5's, but even better with my 2.2's. So eventually the 85 ended up with the 2.2's in my second system, and I started looking for ST-150's, which are VTL's "Big Brother" to the ST-85s. The 150 is a brute-force amp powered by two quad's of 6550 or KT88 tubes and massive VTL transformers. The thing weighs over 65 pounds out of the box and puts out 150wpc into 5 ohms, which happens to be the Thiel 3.5's actual impedance for a perfect match. But the aspect that really enticed me is it's ability to be switched to Triode mode, where it puts out 65wpc of pure tube bliss. My system has now reached a state of musical finesse never before experienced. So Sandy was right in claiming that his Triode tube amp used with the 3.5's took him to a new place.
The moral: if you want to try tubes with Thiels, don't be shy .... but make sure you have 60 or 90wpc, and if it is triode, even better. And I can highly recommend these two VTL amps for the purpose.
I was going back and reading this thread starting where I join in with my drama. I had remembered that someone who actually owned the 3.7 and 2 x AHB2's AND was a classical musician said that the single AHB2 was preferred over 2. I always like to hear what a musician thinks of gear because they have more experience in real music than me.
Here is some comments emailed to me from John Siau on the compatibility in relation to Stereophiles comments.
3.8 Ohms at -40 deg is not a problem. You will not hit over-current shut down, even in mono mode.
The maximum SPL in mono mode will be about 6 dB higher than stereo mode.
The unique thing about the AHB2 is that it stays clean when driving low impedances and difficult phase angles.
Anyways, there is enough info now in this thread on the 3.7 + 2 x AHB2 synergy that we can put it to bed. People can make up their mid based on the great comments here. I am sure people would like to get back to regular scheduled programming.
This new video From Ayre Acoustics and John Atkinson of Stereophile is just in time to explain why the CS3.7 won’t be liked by many amps, "especially bridged ones." And not only because it's closer to 2ohm rather than 4ohm
It’s got the discussed "equivalent peak dissipation resistance" (EPDR) which I mentioned a page back, which is the combination of -phase angle and resistance at a given frequency, in this CS3.7 case at 60hz where much power is needed. https://youtu.be/TRGrvd_cTHI?t=555
I find all the handwringing about whether a well designed solid state amp will drive the 3.7s surprising, given, as I've said, they were driven with aplomb, as loud as I could stand, by 140W of tubes (and even with a 14W integrated Eico amp).
"The vertical bi-amp will not work with the Thiel CS3.7 since it only has 1 set of speaker inputs."
Check out bettlemania's system on the virtual systems , he bi-wired his 2.4's .
Yes it's very easy to do, "if" the owner or a friend has a little knowledge. Once again do not bridge into these CS3.7's, you'll gain loudness at the expense of sound quality and reliability. This is stretching it, but bridging turns what was a good quality amp into a more powerfull P.A. amp.
@vair68robert That is something to consider since I already have a speaker repair tech available to help me now.
1) I have to fix the broken thread on the LEFT speaker frame for one of the screws. I have repair kit being shipped for that. Hopefully I do not mess up that repair.
2) I have to fix the SPL divergence issue between the 2 COAX drivers. I hope it is not a crossover issue and a simple COAX driver replacement, to the 2012 spec'd COAX, does the job.
3) I want to sand an lacquer the wood since it has some ugly sheen on certain angles. That was a prior DIY job not from the factory.
4) Setup the outriggers that arrived yesterday, though I will do that last.
5) Maybe add this bi-wire ability
Fun times and all I wanted to do was buy a speaker.
I was about to buy a second AHB2 last night on USAudiomart, but my PayPal was not setup the way I wanted. It will be tempting in 2 business days once my account is adjusted. Smarter move maybe be to pay a little more and do a home trial.
One thing that goes in my favor in buying a second AHB2 is that I have an orphaned KEF LS50 that needs some power. I was thinking the NAD M33 for that but I can happily get an AHB2 for that again.
Here is blurb from the AHB2 manual that I read last night. Which should be good for my small room situation where I won’t be blasting it full blast.
"Speaker impedance always varies with frequency. Speaker impedance may be much lower than the rated "nominal" impedance at certain frequencies. The over-current fault detection circuits prevent potential damage that can be caused by driving very high signal levels into very low impedances. In STEREO mode, at full output, the current limit can be reached if the load impedance dips below about 1.3Ohms. In MONO mode, at full output, the current limit can be reached if the load impedance dips below about 2.6Ohms."
So if I do hit these limits then the amp will shutdown. I am assuming that VERY HIGH LEVELS means high volumes.
@tomthiel, you seem to be referencing your experience with the AHB2's with the Thiel CS 2 2 's but most of the conversation here is in regard to the Thiel 3.7's. https://www.stereophile.com/content/thiel-cs2-2-loudspeaker-measurements https://www.stereophile.com/content/thiel-cs37-loudspeaker-measurements https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier We can see that while the 3.7's appear more sensitive than the 2 2's, the 3.7's work at a lower impedance. The 3.7's are also recommended for greater power input, perhaps to compensate. The AHB2's would seem a bit more comfortable providing comparable useable power into higher impedances than comparable useable power into lower impedances. Though not conforming to ideal textbook performance, the AHB2's are spec'd to the 2 2's load. However, I think that the crux of this conversation is in regard to the impedance and the corresponding specifications of the AHB-2's into the load at hand for the 3.7's, for which they are not. The difference between a 3.5 and a 2.4 minimum impedance load is not insignificant. Forgive me if I appear jaded, but that "John is adamant that the AHB-2 has enough power. Engineers can be that way." sounds more like he's wearing his marketing hat, rather than his engineering hat.
"The vertical bi-amp will not work with the Thiel CS3.7 since it only has 1 set of speaker inputs."
Check out bettlemania's system on the virtual systems , he bi-wired his 2.4's . So with a little drilling and soldering you can have bi-wiring for bi-amping.
To clarify for those recently joining the discussion, my observations are based on an unusual room that is effectively large since the listening room has semi-porous walls within a 12Kcubic’ space, in a 30Kcubic’ building without many partitions. I also have modified the speakers for 3 separate inputs rather than a single pair. I listen at approx 90dB peaks.
Under those conditions the pair of bridged AHB-2s never clip. I had hoped for a configuration with a bridged AHB-2 driving a woofer and another one (adjusted for matching gain) used in stereo mode with one channel driving the midrange and the other the tweeter. Alas, the upper amp clipped regularly in my conditions. But, in less demanding conditions that setup works quite well.
@unsound,
90 dB at 2.83 V 1/m into 4 ohms means current = 2.83/4 = 0.7075. Watts = current x voltage = 0.7075 x 2.83 = 2 watts. 90db at 2 watts, 93 at 4, 96 at 8, 99 at 16, 102 at 32. Regardless, the older I get the more I'm convinced that the way to go is to have a couple of systems. My den (I guess you'd call it) has my Thiel system, and my family room has my rock 'em sock 'em robots system. I'm guessing this is actually cheaper than having a single system that tries to do everything. I've got around 27k in both systems combined but components going all the way back to 2003. Less than 2k/year, not an extravagant hobby by any means.
When I spoke to Rob Gillum about the robustness of the COAX he said that it was something that should last a very long time. However, he observed that most of the damaged COAX drivers occurred because people thought a $13K speaker can play as loud as an amp was capable.
I blew out my old Revel Salon 1 tweeters a couple of times with my Bryston 600 watt mono blocks. I have learned my lesson of playing too loud.
What this means to me is that the 3.7's are my permanent take to the grave office speakers (not blasting it in the office). I will get something else for my living room.
This same AHB2 conversation was had in another A'gon thread in 2018 where John Siau participated. I don't think the folks responding to him realized he was the amp designer.
The vertical bi-amp will not work with the Thiel CS3.7 since it only has 1 set of speaker inputs.
As it stands:
1) The designer of the amp told me by email that the amp will be good with the speakers. He looked at the speaker specs. 2) The founder of the speaker company mentions that he has been testing 2 AHB2 for the last 2 years. 3) @unsound makes a great point about finding something else that does not shut down. I think there will another amp in the future to have in the stable.
At this point a second AHB2 is an easy buy for me. I love the sound of this amp. They are said to work with the 3.7's, issue is how well. One thing I have learned the last 2 weeks is that the CS3.7 is not a speaker to be played crazy loud. That is fine for my current application in my office. A little more grunt from the 2 amps will take me to an ideal spot.
What the member who’s thinking of bridging should do if he must get another ABH2, instead of bridging it, which will be a step backwards with these CS3.7’s in all parameters except total wattage.
He should vertical bi-amp the two ABH2 amps, that way the whole power supply energy is available to just one bass speaker of one channel instead of two. The amp/s remains stable and able to drive these nasty loads. https://www.av2day.com/wp-content/uploads/2014/05/biamp2.jpg
Rory at Benchmark says that many customers have requested such an AHB-3. I tried my hand at it. John is adamant that the AHB-2 has enough power. Engineers can be that way.
We wouldn’t be talking about this here if Thiel speakers had 4 ohm minimum impedances.
but its anomalous behavior is limited to its stability into low impedences, BUT if it does become unstable, it tells you via indicators
This may "save" the amp if the protection circuit is fast enough if it oscillates and there’s not too much storage capacitance, as you’d be crazy to put relays/fuses etc in the speaker outputs or power supplies. (another sound quality no no) I did say just one of the negatives was stability and low impedance drivabilty, there are many more.
I suppose it’s a good thing that this amp protects against overload, but I can’t help but think having extra power margins into lower impedances and the superior frequency linearity that come with it, wouldn’t be better. I’d rather an amp just keep delivering when called upon than shutting down, even if just briefly. As of now it seems as though there are better options available. Perhaps a beefier AHB3?
George - I agree that all amps we know, either class A or AB, act worse in many ways when bridged. I recommend you investigate this particular amp, which does indeed act as you say, but its anomalous behavior is limited to its stability into low impedences, BUT if it does become unstable, it tells you via indicators, and protects itself. I had dismissed it for myself before I looked closer and now have used it for a couple of years. Check it out.
When you do this the "sound quality" not the loudness will deteriorate. As when any amp is bridged, the there are many negatives that happen, one is that will be here is the ability to drive low impedances and the stability into low impedances. Look at the impedance graph of the 3.7's, it's nasty. If you need more watt's get a bigger amp.
@jafant I am listening to the MoFi version of Santana's Caravanserai and I am amazed to how good it is. Maybe my second best SACD disc now after DSOTM.
There is no comparison with the SME version. The MoFi has bass that I can feel on my toes as I am stretch out listening. Not bass that bothers the ears but bass that should sound loud. The percussion is more powerful and you can feel it. You hear more of everything, and it is not a louder recording just a more vivid rendering.
ampers - I’ll chime in here. The Benchmark AHB-2 has been my go-to amp for about 2 years now. It is unique in my experience for simple authenticity. Regarding their feed-forward, John Siau has written a white paper available on the BM website. In practice, the correction mechanisms are nearly invisible and inaudible. Under overload / clipping conditions (evidenced by the indicator lights), I can hear no artifacts of any kind. The error-correction compares the input signal with the projected output signal and introduces correction before the final power stage. When pushed ’too hard’ the output interrupts momentarily as though the offending peaks are erased, but with no audible distortion, mute indicators light up momentarily - and the music continues. I have purposely pushed the bridged amp into sub 2 ohm loads (two paralleled CS2.2s.) The over-current lights flicker on peaks and eventually the amp shuts down via overheating. No damage, no audible distortion, just safety shut-down waiting for manual restart in a few minutes.
Don’t try this at home. But my experience is that the AHB-2 is bulletproof for itself and its driven load.
In my large room, I run out of power in stereo mode and therefore use 1 bridged amp on each channel. Unlike class AB amps, the bridged distortion graphs match the stereo graphs. But output impedance is double (damping factor is half). Half-length cables makes up for much of the difference.
Considering the relative bargain price of the AHB-2, my dream configuration (seconded by John Siau) is 4 bridged AHB-2s -each channel getting a bridged amp for the woofer and another bridged amp for the combined midrange - tweeter. Power requirement is about equal, since the headroom required for clean midrange peaks about equals the current draw of the bass.
I’m picking up my AudioQuest 9 cables this weekend other than that nothing yet. May get more interconnects but as far as speaker cables go I have one for each speaker. The AudioQuest was terminated for the thiels. I chose the 9 for the natural warm timbre without detail smothering.
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