Thiel Owners

a response from Rob Gillum to a question i had asked him

The CS3.7 cabinet is pressurized from the woofer and it is true that if there is an air leak between the main cabinet and the coax chamber, it will cause unwanted pressure to the coax midrange. This can cause the midrange driver excursion to be greater, which in turn will cause the midrange to fail. To check for the leak, you can gently push in on the woofer and Passive diaphragms at the same time. This will pressurize the cabinet, and no movement should come from the coax midrange. The midrange diaphragm is connected to the coil former via 25 points of a special adhesive. If the CS3.7 is driven hard, then it is possible for the glue joints to break. If only a few break, then the end result is distortion. If many of the glue joints break, then the excursion will become great enough for the lead wires to the mid to break. This will render a dead mid.

When sealing the coax chamber, use a caulk containing silicone. Door and window. There are two pieces of tubing which carry the wires into the chamber. Make sure that the wire tubing is not leaking as well. At the factory, we injected some hotmelt into the tubes to seal the wires. Also make sure that the tubing is not leaking around the holes in the divider.

In my limited experience with repairing Thiel 3.5 midranges a couple of years back the performance of Thiel in general warrants what is truly an “investment” as opposed to a mere “repair”.  Even with the $600 + dollars invested into a pair of speakers that cost me approximately the same,  (methinks) where could one spend $1200 on a pair of new speakers and get the performance/Sonics of Thiel?

We all know the answer to that question. 

I just sold off my pair of 3.6 to a fellow member who drove 250 miles to pick them up - amazing how Thiel fans are willing to spend the time and effort to get ‘em, ain’t it?  I drove an equivalent distance to pick up my first pair of 3.5’s. 

I drove an equivalent distance to pick up my first pair of 3.5’s.

I recall reading on audioasylum that Charles Hansen thought the 3.5s were Thiel's best sounding speaker with the 3.7s a close second. But maybe I'm hallucinating as I can't find that post now.

To check for the leak, you can gently push in on the woofer and Passive diaphragms at the same time.

I'm very reluctant to try this. Supposedly, dimpled drivers have no measurable or audible effects but . . .

Maybe you can use something with a bigger surface area than fingers yet still softish?

ronkent

To check for the leak, you can gently push in on the woofer and Passive diaphragms at the same time.

beetlemani

I'm very reluctant to try this. Supposedly, dimpled drivers have no measurable or audible effects but . ..

To check for the leak, you press on the diaphragm, not the dustcap.