The T's sound perfect at either low volume or very high levels... makes no difference and I cannot hear any difference at all from what they have always played like. It's just that the amp suddenly shuts down the channels feeding the woofers.
I spent a lot of time on the phone with Bryston today, we did a lot of tests. Putting my Fluke multi meter across the inputs on the speakers feeding the woofer section, I measured 3.8 ohms and 3.3 ohms on the one which corresponds with the overheating amp channel. The shorted resistance reading on the probes of the meter is at .2 ohms, so subtracting this out from the above reading equals 3.6 and 3.1 respectively. This is DC ohms, resistive no AC impedance. If I recall, the AC reading in impedance would be slightly higher than the DC reading.
There is about a 15% difference in impedance between the two speakers in the pair, that is pretty close to the difference in the heat I am seeing on the amp. When it shuts down on one side, the temperature is hitting 150 degrees F vs. around 130 degrees on the other side. I think there has been this difference in heat as long as I can recall, but the amp is not handling it suddenly.
I pulled the three woofers from the low reading speaker today, I read 8.2, 8.4 and 8.7 DC resistive ohms on the drivers. I don't know what the proper spec is, but again to hit 4 ohm nominal, each speaker would have to be 12 ohms AC, it seems these readings are a little low. If all three were at the 8.7 range, the speaker would be more matched to the other T.
I am waiting to get information back on what my readings say. I think that if the speakers were around 9 or 10 ohms DC that would equate to around 4 ohms AC impedance.
Last edited by Slimpikins; 01/23/18 01:26 AM.
