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I have had a couple of speaker failures in a bass rig but I don't know if the problem I'm having is an amp problem or a speaker/enclosure problem. I have a regular jam with some friends and for a bass amp I use my Ibanez Promethean 300 watt 1x10 combo. The internal speaker doesn't give enough volume, so I use an external 1x15 speaker box (homemade) that belongs to one of the other guys. In this configuration I am running the external 8 ohm in parallel with the internal speaker (which is a dual coil speaker that will be 8 ohm when using an external speaker). I don't think the amp does 300W RMS, my guess is that is a peak or program number. I don't have the amp available to me right now and don't remember what kind of power amp it is using or voltage rails..
The problem is that I've trashed two 15" Peavey Black Widow speakers that should be able to handle 300W on their own, so assuming the Promethean is sending no more than 150 watts to the external speaker (and I suspect it's less) I don't know why the speakers are getting damaged. The last one it almost seemed like the speaker voice coil had travelled too far out and gotten dislocated. When I went to test the movement of the voice coil by pushing down it felt like it popped back into place, but it still giving distorted/ragged output.
After the first speaker died I tested the amp for DC on the output and it was fine. Neither of the BW speakers was new when I started using them, so there is a possibility they were both weak to start with. I'm wondering if anything with the construction of the speaker box could be causing/letting the speakers travel too far. The Promethean is voiced very low (probably to compensate for the small internal speaker enclosure). Would something like a too big port in the cabinet potentially cause damage? The port on the box to me looks too big (with essentially no length) but I'm not a speaker box guy. Or could it be that I am overdriving the amp and stressing the speakers that way? The bass doesn't sound distorted (when the speakers are working) but I do have the amp pretty much dimed to get enough volume out.
The setup is used for less than two hours once a week. The speakers have both worked well for a while (more than a year) before failing, so I can't even tell if there is a real problem or coincidence or something else.
Thoughts?
Greg
The problem is that I've trashed two 15" Peavey Black Widow speakers that should be able to handle 300W on their own, so assuming the Promethean is sending no more than 150 watts to the external speaker (and I suspect it's less) I don't know why the speakers are getting damaged. The last one it almost seemed like the speaker voice coil had travelled too far out and gotten dislocated. When I went to test the movement of the voice coil by pushing down it felt like it popped back into place, but it still giving distorted/ragged output.
After the first speaker died I tested the amp for DC on the output and it was fine. Neither of the BW speakers was new when I started using them, so there is a possibility they were both weak to start with. I'm wondering if anything with the construction of the speaker box could be causing/letting the speakers travel too far. The Promethean is voiced very low (probably to compensate for the small internal speaker enclosure). Would something like a too big port in the cabinet potentially cause damage? The port on the box to me looks too big (with essentially no length) but I'm not a speaker box guy. Or could it be that I am overdriving the amp and stressing the speakers that way? The bass doesn't sound distorted (when the speakers are working) but I do have the amp pretty much dimed to get enough volume out.
The setup is used for less than two hours once a week. The speakers have both worked well for a while (more than a year) before failing, so I can't even tell if there is a real problem or coincidence or something else.
Thoughts?
Greg
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