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[Albert Thomas]

 Just starting out in sound reinforcement but I've been in the electronics for some time. I picked up some entry level stuff (EV eliminator doubles with the EV I-subs) which have built in passive x-overs in the subs and mains. I'm using Crown amps with built-in filters so I can bi-amp them. Is worth the effort to remove the low pass inductor in the subs if I'm sending only <80hz to it? If I remember my electronic theory correctly below 80hz the inductor should act like a piece of wire, but I'm thinking waveforms with sharp rise times may get blurred.  Going a step further, would it be worthwhile to amp the bottom 15" (tri-amp) which has a crossover at 700hz and leave the passive between the top 15" and the CD horn.

Thanks in advance.

Albert Thomas

[chuck clark]

It should act like a wire below 80 hz. so no prob there. the only waveforms with fast rise times are hi freq's (as in square waves?) so you would be protected from amp clipping.  The only question is current load cabability. Older boxes were designed before modern day amps were putting an actual 1000 watts thru them so, you don't want them burning up. What gauge wire are the windings? It shouldn't be a problem as long as your running a nice clean unclipped, uncompressed signal to them. I wouldn't bother tri-amping. You need more rig before triamping is going to help. Good luck!
Chuck]

[Albert Thomas]

It should act like a wire below 80 hz. so no prob there. the only waveforms with fast rise times are hi freq's (as in square waves?) so you would be protected from amp clipping.  The only question is current load cabability. Older boxes were designed before modern day amps were putting an actual 1000 watts thru them so, you don't want them burning up. What gauge wire are the windings? It shouldn't be a problem as long as your running a nice clean unclipped, uncompressed signal to them. I wouldn't bother tri-amping. You need more rig before triamping is going to help. Good luck!
Chuck]

Thanks Chuck,
Without going out to the garage and getting my calipers, my eyeball gauge reads 14 or 16awg. So even if it's only 16, that should still be good for 1kw peaks no? 13A (16awg. ampacity) X 8ohms= 104V X 13A = 1.3kw.
The EV subs are rated for 400w EIA and 800 to 1000 peak and the Crown XLS 2500 is rated for 440w @8, so I'm guessing I wouldn't be able to notice any difference if I bypassed the coils. 

[Randall Hyde]

Thanks Chuck,
Without going out to the garage and getting my calipers, my eyeball gauge reads 14 or 16awg. So even if it's only 16, that should still be good for 1kw peaks no? 13A (16awg. ampacity) X 8ohms= 104V X 13A = 1.3kw.
The EV subs are rated for 400w EIA and 800 to 1000 peak and the Crown XLS 2500 is rated for 440w @8, so I'm guessing I wouldn't be able to notice any difference if I bypassed the coils.

I'd be very wary of using anything less than 12AWB cable, particularly if you're running at 4 Ohms. 16AWG and 14AWB might handle the current just fine, but the extra resistance kills the damping factor on your speakers.  You don't need fancy, super expensive, "monstrosity" cable, 12AWG from your local Home Depot will work fine.  Bigger is better. Always (okay, beyond 10AWG it's kinda hard to attach the wires to the speakon connectors, but you get the idea). Of course, shorter is better, too. Try not to exceed 50' (keep in mind the current has to make two trips down the distance of the cable, so the resistance is doubled).

[Albert Thomas]

I'd be very wary of using anything less than 12AWB cable, particularly if you're running at 4 Ohms. 16AWG and 14AWB might handle the current just fine, but the extra resistance kills the damping factor on your speakers.  You don't need fancy, super expensive, "monstrosity" cable, 12AWG from your local Home Depot will work fine.  Bigger is better. Always (okay, beyond 10AWG it's kinda hard to attach the wires to the speakon connectors, but you get the idea). Of course, shorter is better, too. Try not to exceed 50' (keep in mind the current has to make two trips down the distance of the cable, so the resistance is doubled).

Thanks Randall, I'm using 25' Pro Co power plus 12awg amp to speaker, what Chuck was referring to was the solid wire gauge of the low pass chokes in series with the sub drivers inside the cabinet.  The internal wire from the choke to the speaker is only 16awg so I'll re-wire with 12awg even though I don't think it'll make a difference for that short distance, I feel it's the right thing to do. I'm thinking since I'm in there soldering I also may as well bypass the choke anyway. 

[George Dougherty]

Thanks Randall, I'm using 25' Pro Co power plus 12awg amp to speaker, what Chuck was referring to was the solid wire gauge of the low pass chokes in series with the sub drivers inside the cabinet.  The internal wire from the choke to the speaker is only 16awg so I'll re-wire with 12awg even though I don't think it'll make a difference for that short distance, I feel it's the right thing to do. I'm thinking since I'm in there soldering I also may as well bypass the choke anyway.

16ga internally for that short a run should be fine, but it never hurts to have larger if you're bypassing the passive crossover anyway.

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