Thiel Owners

Yyz - the definitive test is to make a momentary connection from a 6 volt lantern battery (or other 6 volt DC source) to the XO inputs. All drivers should move forward. You can readily see the woofer and midrange move, but may have to feel the tweeter. And Thiel uses silver solder which has a higher melt temp than utility solder. A 140 watt gun is just right.

Thanks everyone for the great info provided here. It has made this problem pretty easy and fast to resolve. I have a speaker repair tech from the local high end audio store coming to my home next Tuesday. The cost is not much for 1 hour work and the speaker seller has volunteered to cover the expense. The estimated cost is pretty low (so far) so not concerned. I will have everything ready to just unsolder and re-solder.

The speaker tech is aware of the battery test though the sound engineer in Canada told me to send him another set of measurements and he will tell me if it is setup correctly. I will see how experienced the repair guy is before I figure out which way to test it.

I received the following feedback from Rob Gillium today about the wiring.

The CS3.7 is a three way speaker, with a Passive Radiator. Each crossover section has a pair of output wires. There are three pairs. One pair to the woofer, one pair to the midrange (coax), and one pair to the tweeter (coax). The coaxial driver is a two driver combination, (midrange and tweeter). Each driver has a pair of wires. The white output wire is positive and should be connected to the red terminal of each driver. The black wire is connected to each unmarked. terminal of the drivers. These wires must be connected in this fashion, to be in phase with each other. If one of the drivers are connected out of phase (reverse polarity), then it will cancel the output from the other driver, thus rendering poor sonic quality. It is very important to connect the midrange pair to the midrange, and the tweeter pair to the tweeter. If these are connected wrong, then the tweeter will see the mid frequencies, and be destroyed in most cases.

I was also speaking with a CS3.7 owner in Brazil who is active on the ASR forum and he thought the Coda #8 V1 would be what he would select from the #8 options. However, he did mention that Purifi is going to come out with a new module that will have similar specs as the NC1200. He is waiting on that before any new amp purchase. He suggested I do the same.

I have a feeling the current Purifi module sounds very similar o the AHB2. A future module with the the same sound but NC1200 power specs would be great for the CS3.7.

I should say again how happy I am that I payed attention to TomThiel’s post about positioning. I was initially trying to get max space between the speakers with low side and later low front wall spacing. Now with the speakers around 2 feet from the front wall, 2 feet from the side, and only 6 feet in-between, the sound is really good, the best so far.

Yes, the side and front wall reflections are quite important. Your room is quite narrow, since the polar pattern of the CS3.7 is quite omnidirectional. Can you try putting them on the long wall?

I cannot play with the placement other than these minor movements. I bought the CS3.7 on the assumption that if it did not work in the office. I could eventually move them downstairs to the much larger living room. The living room is my sons play room at the moment.

However, the placement that I just did is great. Given the circumstances of this room I am extremely happy about the sound, except for that harshness. which will be resolved on Tuesday.

I will say to prospective CS3.7 buyers that the speaker will play in a acoustically treated room small room, see my Virtual System on A'gon. I understand that I am not getting the very best sound out of the CS3.7 but, what I am getting is very good. 

Reading everything on the web on this room size issue made me think it would not work. I am shocked actually that this is working so well and I am not getting overwhelmed with bass. I still have the DRC implementation that I can bring to the table to potentially make things even better.

unsound & thielrules - about individual amps. I’ve been comparing configurations these past few days and conclude that it’s very murky water. I have matched pairs of Adcom GFA-555 mkII, Classe DR9 and Benchmark AFB-2s. The power is similar, but the clipping characteristics are different. Even with using same source, preamp, cables and speakers, the amps’ characters change when stereo or bridged and how hard they are pushed. All things considered, it would be hard to make any ’best recommendation’. I agree with unsound’s thought about ’same amp’ for bass and treble. Gain matching is very important as well as overload characteristics.

At this point what I can say for sure is that among my amp stable, the AHB-2 is the cleanest, clearest, most harmonically convincing. To my previous comment about its possible bass ’deficiency’: I suspect it is outputting most accurately, even though other amps might be more appealing. After speaking with John Siau of Benchmark and poring over test results of all the amps, I’m convinced that the AHB-2 stays extremely clean (until it clips), whereas other amps delay bass frequencies which is experienced as hanging longer in time, and produce harmonic (distortion) addenda which is experienced as more amplitude. Combining time delay and more harmonics produce bigger bass. But, the AHB-2 bass is so clean and articulate with considerably more inner harmonic detail. The problem still remains that it admittedly produces "less" apparent bass than other amps, so the producers’ intent may have more bass than the listeners’ experience with the AHB-2.

My preferred setup is running a pair of AHB-2s in bridged mono, each driving a full-range speaker with 3 separate, identical cable runs (or two runs that combine midrange and tweeter feeds. I rigged some 6’ and 12’ runs and cutting the runs to half length increases damping factor by 2 and tightens up the bass that was loosened by bridging. If I could afford to splurge, I would use 4 AHB-2s, all bridged. One for each channel’s woofer and the other for the mid-tweeter. But, I don’t feel the need, a bridged pair doesn’t clip in my situation, and unlike normal amps, the AHB-2 distortion stays near zero into any drivable impedance until it clips. JS says that impedance limit is around 2 ohms, so some Thiel models are in jeopardy. But I haven’t experienced it with my 2.2 and 3.5 testing. I wish Jim had kept his loads above 4 ohms nominal, 3 ohms minimum to stay out of trouble.