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I am not a huge expert on speakers and cabs, really just starting to explore.
I've recently acquired a pair of mint 15ohm Celestion G12 Alnico Golds from a great GC member and just got a chance to install them into a custom cab that I acquired last year. The cab is 3/4" solid pine and the speaker baffle is 3/4" Baltic bitch plywood. The cab was originally set up as a large 1x12, but included a 2x12 baffle which I grill clothed and installed. I have not (yet) heard this cab with another speaker. On the pictured jack plate, double all impedances -- the fancy jack plate is only available labelled for a pair of 8ohm speakers.
The issue is that this setup is super (super!) bright. It is also very directional -- I can drastically change the spacial sense and sound by shifting my head a few inches when 6-10 feet in front of the cab. I am using the "4ohm mono" jack, which in this configuration is 2x15ohm in parallel so about 7.5ohm. I am using multiple amp heads on their 8ohm outputs. I have another 8ohm 2x12 cab available for comparison and it is completely different with all amps, in same space, at all volumes.
Any explanations or advice? Is this "normal" (not at all what I was expecting from this setup from my readings). Is open back the right way to run these speakers? Is the root cause the cab or the speakers? I don't think there is anything wrong with the speakers as they otherwise sound clear and look fantastic. Is this just the nature of efficient speakers?
Note that all of this testing is in a medium-sized basement, but it is finished, carpeted, with soft furniture, drywall walls, and plaster ceilings (no hard concrete surfaces) and I have turned it up for testing -- the brightness is there at all levels.
I've recently acquired a pair of mint 15ohm Celestion G12 Alnico Golds from a great GC member and just got a chance to install them into a custom cab that I acquired last year. The cab is 3/4" solid pine and the speaker baffle is 3/4" Baltic bitch plywood. The cab was originally set up as a large 1x12, but included a 2x12 baffle which I grill clothed and installed. I have not (yet) heard this cab with another speaker. On the pictured jack plate, double all impedances -- the fancy jack plate is only available labelled for a pair of 8ohm speakers.
The issue is that this setup is super (super!) bright. It is also very directional -- I can drastically change the spacial sense and sound by shifting my head a few inches when 6-10 feet in front of the cab. I am using the "4ohm mono" jack, which in this configuration is 2x15ohm in parallel so about 7.5ohm. I am using multiple amp heads on their 8ohm outputs. I have another 8ohm 2x12 cab available for comparison and it is completely different with all amps, in same space, at all volumes.
Any explanations or advice? Is this "normal" (not at all what I was expecting from this setup from my readings). Is open back the right way to run these speakers? Is the root cause the cab or the speakers? I don't think there is anything wrong with the speakers as they otherwise sound clear and look fantastic. Is this just the nature of efficient speakers?
Note that all of this testing is in a medium-sized basement, but it is finished, carpeted, with soft furniture, drywall walls, and plaster ceilings (no hard concrete surfaces) and I have turned it up for testing -- the brightness is there at all levels.




