Search the Community
Showing results for tags 'Tri-amp'.
Found 1 result
-
What I am running: 1978 Klipsch Belles w/ all original horns and drivers, Tri-amped Xillica 4080 DSP – (HP Xover set at 4900 HZ LW 24 dB) for the Tweeters (2) First Watt M2s – A left and right feeding the MF and HF. McIntosh C32 Pre McIntosh MC2205 – Feeding the bass bin Gain Delta set via volt/ohm meter, attenuation on the McIntosh knobs. I have been on the exploratory path of digital xovers. I have in the last few months added the M2s and the Digital xover into the system and went the tri-amp route on the Belles. I am very happy with the sound and feel I have it at about 80% there although I am fine tuning. But I have run into a problem that I can’t seem to solve. This past weekend I discovered that my Right Tweeter was no longer working and I discovered it to be an open circuit. The diaphragms I run are replacements that are less than a year old from Simply Speaker. So I ordered up a replacement and on Tuesday replaced the diaphragm. This diaphragm lasted about 15 seconds under mild use and stopped working while I was testing. I shut it down and proceeded to check the ohms and saw a funny thing, it was floating around, not a direct short nor was it an open circuit. I checked all the wiring to the xover and the freq slopes and this took about 10 minutes. Upon one last check with the OHM meter the diaphragm measured OK so I plugged it and it worked for a about 10 seconds then I heard a crackle and now it measures completely open. I suspect I have overpowered or overheated it. But have no idea how or why. After it blew it the second time I tested the outputs of the M2 and was at less than .5Vrms which is under 1 Watt per the M2 sensitivity specs. My theory is that I overheated it to the point it seized the first time and after it cooled it was OK until I tried it again this time going all the way with it. I contacted Nelson Pass, (what a great guy): The M2 does not amplify DC, so that is unlikely, but you should check for DC at its output with a voltmeter (I test none). I assume that you have a capacitor in series with the tweeter in any case. The M2 also does not amplify very high frequencies, so that’s kind of unlikely also, but there is a possibility that ultrasonic oscillation exists in the system. I think the most likely source of the problem is that the crossover frequencies or slopes may be too low, sending more energy to the drivers than you think. (See setting above, this setting is widely used) One of the things I wanted to try and do was blow the other one… I flipped the system left for right and cannot get the left one to blow using the exact same setup. Maybe I just had a bad diaphragm? Or I have one that just won’t blow… I don’t know. I do not have a capacitor in series, do I need one? Is that to protect against the DC? Would this fix my problem? Tomorrow I have 2 more diaphragms that will arrive, and I am really thinking of pulling that active and the tri-amping and going back to one amp and a passive. It has been recommended that I go with a zeener diode, but if that is the only logical solution, I will go back to the passives. Although I feel though that the improvement the tri-amping this has made, is not worth giving up on just yet… Please share your thoughts even if they include "go back to passives". I have attached an unrelated photo of my system as I try and fix this issue and run some dedicated outlets. Thanks for your time. Joe
