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Ron; One of your posts mentioned your hearing issues If played to loud "my ears buzz like a tweeter" We hear the same way & especially with compressed 80's rock albums. My hearing starts howling...lol I feel your pain....... Have you had a hearing test, lately? I have my hearing accentuate at the crossover frequency Does the loudness/Tweeter happen on well recorded stuff, too? Do any of the filter setting on the PS Dac , help attenuate it? Jeff Ps: I hear the crossovers in the 3.7 were by Jim The 2.7 was done by Phil Bamburg of the speaker builder in Indiana Any correlation ? |
Welcome! gasman117 (Dave) I think that you will find the CS 2.4 to become a real honey of a loudspeaker in your system. Those older Adcom power amp(s) are still pretty good, enough so, to get you up and running. Proceed made excellent gear as well. There are repair technicians here in the U.S. for most of their products. Keep me posted as you massage this speaker into your system/room and obtain other gear to enhance the experience. Read over this thread from the beginning and you will find a plethora of valuable information from contributors and experts on Thiel Audio. Happy Listening! |
Thanks jafant, i’m picking up a set of 2.4s this weekend! cant wait but then I gotta clear out the listening room, get my old cables out, move the pitiful advents i’ve been listening to, dust off the Proceed CDP. My amp right now is an adcom 545 i got cheaply. I’m looking for a reasonably priced Classe . ill keep you informed! dave |
hi Tom, my understanding of this is bare bones at best. i did replace a few coaxes and do not remember seeing any with a resistor on the positive terminal. could that be a reason for my proclivity to blow drivers? When i sold my 2.7's i sent the extra coax that i had for it and it did have the resistor as it was my back up driver. |
Ron, I don't have enough history to comment on your situation. I am far away and out of touch and coalescing probabilities from sketchy
evidence. The detailed lab records are MIA and most of what we know is in
Rob's memory. I am gradually back-engineering XOs and timelines from photos, previous suppliers input and whatever Rob sends me. Rob says that Thiel built all 2.7s in Lexington under his supervision, so he knows far more than I do. The schematic that I created from an engineering layout shows the tweeter with a parallel pair (20+3) netting 1.3 ohms in the tweeter series feed. It is possible that value was adjusted over time. Rob would know his rationale and I do not. |
thanks Tom, that is interesting if i understand correctly about the resistors. when i sent back the last damaged coax to Rob, he sent the replacement back with a resistor on the positive terminal. to the best of my recollection, none of the others had that resistor. could the lack of that resistor make the drivers more prone to damage? |
I'll try to find out something from Rob about the 2.7 vs 3.7 failures. Same driver. Thieliste, good investigation. In the day Thiel, especially the CS5, was very successful in Japan. Luxman amps were the clear choice in ultra high-end systems. They are seriously good. The amp you reference is still doubling into 1 ohm, and their engineering choices are musical (most Japanese amps are not, in my opinion.) |
thank you again TT. your input here is so appreciated as is the research you are doing. it is a puzzle to me why i have had bad luck with the coaxes in the 2.7's, and maybe it was a bad batch. i use Analysis Plus speaker cables and they are only 8' runs. the first driver that blew was used with a Marantz reference amp, so no slouch, but the second and third were with the PS amp, so i doubt i drove it into clipping. i have issues in the right ear and it will buzz like a tweeter when the music is played too loud. sort of my canary in the coal mine thing. maybe it is a thing of the past now that i have 3.7's which i think are less demanding on the amp due to the higher input sensitivity. i have had to dial back the preamp from an average listening level of 39 to about 33 (PS BHK preamp). |
Ron, your listening levels and amplification are very appropriate / safe. So something else is going on, perhaps bad drivers, but sometimes cables can induce amp misbehavior that adds stealth distortion. I can't troubleshoot, but I will try to find out the service history of those drivers. Prof, that cliché is true. Tube amps clip softly, without much hash, and therefore are far more gentle on speakers when driven hard than most solid state designs. As an aside, I have played hundreds of Thiel speakers for thousands of hours, often in very demanding and loud situations, and have never blown a driver . . . I have also seen hundreds of "blown" Thiel drivers and in the vast majority of cases the voice coils are burned, which is (practically speaking) only caused by distortion (the driver will produce ear-piercing volume without damage given a clean signal.) Those burned coils are user-damage, but Thiel generally covered them ONCE under warranty as good will. Legitimate manufacturing defects include subtly mis-routed lead wires, magnet-position and/or suspension mis-alignment or glue failure, etc. Those are generally batch problems and result in instant failure (broken lead) or immediate voice coil rubbing. If it's defective it will fail quickly. Part of my upgrade project is thermal management, which is generally ignored in hi-fi, but is very important in sound reinforcement and pro-audio. Heat is a real enemy. It can shift crosspoints radically, which adds substantial stress to the system. A 3KHz tweeter crosspoint can migrate to 2500, admitting damaging low frequency signal to a driver which is vulnerable due to the concurrent high-power situation. So, I am mounting all resistors in heat-sinks mounted to buss bars to dissipate waste crossover heat. My CS2 2 workhorse is getting an aluminum tube spine up the back of the cabinet to sink those buss bars as well as mounting an aluminum tube from the back of each driver which conducts heat as well as provides more mechanical stiffness to the driver mount. I am puzzled that Jim abandoned aluminum voice coil formers for nomex; probably for lower mass and smoother high frequency extension. But thermal conduction was traded off. This note is just to let you know where my investigations are leading. BTW, I have a pretty big pile of foil coils, resistors, wire and caps, plus the Clarity Caps are finally on their way. I'm especially excited about a CC custom polypropylene cap we have developed to replace all the electrolytic caps. I'll be comparing the new CC to the ERSE PulseX Polypropylenes in those applications. Either way is a big step up from the present electrolytics in the shunts. Progress is being made. |
Did any of you consider Luxman amps to drive your Thiels ?If so i would like to have feedbacks.I have been told Luxman would be a very good match.I'm looking at this model : http://www.luxman.com/product/detail.php?id=19 |
tomthiel, What is the role played by the difference between tube amps and solid state amps, which it comes to damaging clipping? It’s something of a cliche to say that tube amps clip more softly than SS.Is this true to the extent that it would be less likely to get damaging clipping from a tube amp of comparable power to an SS amp? I’ve used tube amps since the 90’s . I’ve had a great many speakers, some as insensitive as 82dB and impedance all over the place, and I’ve played them loud. But not once have I ever blown a driver. So I’m wondering if this has much to do with my choice of tube amplification. (I use Conrad Johnson Premier 12 tube monoblocks - 140W side). |
thanks Tom. i guess i play them too loud but i measured and the average is about 78 db with peaks of 85. plus the PS Audio BHK 250 amp is a hoss. I will have to be more careful but interestingly enough, in the past using lesser amps with the older models, and playing at the same levels, they did not blow. my guess is that the newer coax is just a bit more touchy. thanks so much for being on this thread. |
Ron, all of your failures sound like overheated voice coils, either delaminating or in the case of humming along, being loose enough to squirm on the former. The cause is most probably being fed a distorted / semi-clipped signal. The first driver was probably good out of the box and also failed via underpowering. |
Yes brayeagle, it’s great to have custom made stuff from Blue Jeans. I’m going to have some interconnect made, short and long. They have really low capacitance interconnects which is great for some long runs I need, especially to my subwoofers. Though admittedly the really low capacitance of the BJ cables may be overkill for a subwoofer signal which is being low-passed ...what the heck...a little over-engineering never hurt. |
Prof: "
Folks, for those who blew drivers, like the 2.7/3.7 coax, what were the
sonic symptoms? Did the sound just die? Or did a crackle develop in
the sound....something like that?" first time: scratchy sound though i think it was bad from the get go as it happened within two months, or perhaps the amp, a Marantz reference, was not up to par.2nd time: with BHK amp-got the crackle you referred to and it was really obvious something was wrong and Rob said it was blown.3rd time: with BHK-weird as it was more of a hum, almost like the unit was singing with the music, but it added something really weird to the sound. Rob can usually fix them but this one stumped him if i recall. |
pops, I love both the ATCs and the Thiels. Both are great products intended to be as accurate as possible but with somewhat different ways of going about it. ATCs are usually active and the company is mainly known for pro audio. ATC has been building its own drivers for a long time and their philosophy is that if you build drivers well enough you don't need a complex crossover. I think Thiel is not that far from that. Thiel produced passive speakers for home audio so they have different strengths. Thiel had complex crossovers for a long time to fix drivers that weren't as good as they could have been. When Thiel came out with their own drivers the complexity of the crossover dropped significantly per Tom Thiel in this thread. The founders/designers of both companies were piano players. They're both hard science guys. I get the impression that Billy Woodman isn't quite the obsessive perfectionist that Jim Thiel apparently was. Both companies use small diameter midranges which I've found that I prefer. Not sure why, lighter weight leads to faster response or maybe better dispersion. |
Folks, for those who blew drivers, like the 2.7/3.7 coax, what were the sonic symptoms? Did the sound just die? Or did a crackle develop in the sound....something like that? (The only driver I've ever seen damaged in my home is, apparently, one of my Hales T1 monitors which plays the R channel in my home theater.I think it was hit with some too-heavy bass at one point and these days, although it sounds fine with most material, a super low/heavy bass signal will make it pop and crackle). |
I blew the midrange on my 3.7s the first few months I had them. I was listening to Beethoven The Revolutionary loud. I took the driver out myself and it didn't look scorched or anything to me. That was back in 2012 and they've been fine since then. They were an early pair I believe. The serial numbers on the boxes are 41 and 42 I think. I bought them used from Audio Consultants so it's possible they weren't the original boxes that came with the speakers. |
Ok, jafant....I just can not read your last line up of posts and not think of a previous quip someone had made. Along those lines, if your current source of employment dries up I think you can slip easily into another similar gig: https://www.job-applications.com/walmart-greeter/ I kid...I kid....;-) |