Help!! Something wrong with my scoops..

Many thank! could you give me some suggestion about the power that amplifier should have  to drive four of these scoops please? 1500 W x channel should be ok? do I need more power?

Yes, the drivers have an Fs of 35Hz which means they are most likely going to play that frequency as they would do in free air (no air resistance = too much excursion). There is also a second thing to consider when making a HPF which is the box/design's tuning frequency. Anything below Fs and Tuning Freq will probably make the drivers reach xmax very fast, this doesn't mean that they can't reproduce these frequencies but that they have to be put down to a safe level.
Also keep in mind the power you give to the drivers can shift your crossover point, in that case it won't be the power damaging your speakers but the wrong frequencies being played.

40Hz L/R-24 is where I would start, Butterworth 48db has also been suggested here on the forum but I've found it to be complex to use..

As for the amps the more the better, there's plenty threads about amps and HEADROOM.
I would suggest to have slightly more than the Program/Continuous rated power, 2800W could be an example, so the amp will never run out of juice. Having 2800W doesn't mean the speakers will be reached by that amount of power continuously, you need the extra power to give the amp room to breathe and for the initial burst on sub bass duty so that the speaker still receives a sine wave signal.
After that, smart limiting is key to prevent damage. An overly compressed/limited signal will do just as bad as a small, clipping, amp would do.

I suggest you read/ask more about crossovers, filters and amps.

Edited by Darkstar - 03 July 2016 at 9:36pm

Forgot about the wiring part...

You can run any number of speakers on one channel as long as the total impedance is supported by the amp you are using.
Just keep in mind that (in parallel) whenever you double the number of speakers you will halve the resistance: 1 = 8 ohm, 2 = 4 ohm, 4 = 2 ohm and so on.
Power will instead be double each time, but the amp will just give the same amount of power to each speaker:
8 ohm = 1x100W = 100W total, 4 ohm = 2x100W = 200W total, 2 ohm = 4x100W = 400W total.

That said, if you had four scoops and your amp supported 2 ohms operation you could wire all the scoops to one channel with no problem. It would work just as well as connecting each speaker to a single channel of multiple amps.
It is best not to force amps to work at 2 ohm though, some amp designs struggle to deliver continuous power at low impedances, 4 ohm is way safer and pretty much every amp on the market right now will have no problem running it.

So, to answer your question, two scoops per channel will do just fine.

Edit: do keep in mind that most amps give out a little less than double the rated power at lower impedances, powerful amps do that the least and if they do it's to protect the components from excessive current draw/overheating.

Edited by Darkstar - 03 July 2016 at 10:08pm

luton_soundman wrote: Has anybody (who needs about DESIGNING scoops) checked if that driver is even suited to that box???? I havnt had time to look it up. But that might be a good reason aswell as the seriously weak amplifiers

I have, and I know that driver will be average in most Scoops, compared to PD1850, V18-1000, PD1851, Obertons.

Have done so much simming of drivers, and testing  many  drivers in diff Scoop types, I can look at 3-4x T/S parameters of a driver, and tell if it will be poor, average or great in a Scoop, and type of Scoop that matches it.

levyte357- wrote: Eminence Scoop is well known for heavy sub. However, not with Yamaha amps, and "that" 18" driver.

Drop a (pair of) 3801 on the job and show them a 35Hz or greater 24db L-R HPF!


Or slightly more realistically:
Part 1 - wind the HPF up as high as you can bare so you're not overtaxing the drivers or the amps.

Part 2 - Get some amps better suited to High Power @ LF

Part 3 - See if you can wind down the HPF a little now you've got amps that can control the driver properly