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Author Topic: Build a Subwoofer Jon Bartow Master Film Handler Posts: 287 From: Massachusetts Registered: Nov 1999 posted 11-04-2001 08:29 PM                     A word of caution about your amp. You say that when you connect the speaker and turn the amp on the cone goes "forward in a bad way" If you mean the cone goes forward and stays there (or backwards), then you have a serious problem. Most likely DC output. Simple test: put a dummy load on the amp (8ohm 50 watt resistor for example), put something through it (pink noise, 1000hz tone) and test the amplifier outputs with a meter or scope. You should have plenty of AC but no DC (on some meters the DC needle/display will bounce around but it will not stay at one point with AC output) If your amp is putting out DC it is a good way to kill the speaker very quickly (or even catch it on fire!) Jonathan  |  IP: Logged Antonio Marcheselli Phenomenal Film Handler Posts: 1260 From: Florence, Italy Registered: Mar 2000 posted 11-06-2001 02:41 PM                        Jon, No, the cone goes forward when I turn OFF the amp and the cone doesn't stay in a different position. I hear a loud "TOC" when I turn off my amp but I canno realize if the TOC is caused by the voice coil hitting the bottom of the speaker or if it is just a sound created by the amp. It is strange because when the amp was in the theater connected to that woofer I never heard TOC's in the auditorium. Bye Antonio  |  IP: Logged

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